L 77 - 2022-23 (2. samling) - Bilag 1: Høringssvar og høringsnotat, fra uddannelses- og forskningsministeren

Uddannelses- og Forskningsudvalget 2022-23 (2. samling)
L 77 Bilag 1
Offentligt

Portugal Space Reference PTS_EDU_EuRoC_ST_000455

Version 03, Date 04.02.2021

UROPEAN

OCKETRY

HALLENGE

ESIGN

, T

EST

& E

VALUATION

UIDE

L 77 - 2022-23 (2. samling) - Bilag 1: Høringssvar og høringsnotat, fra uddannelses- og forskningsministeren

Portugal Space Reference PTS_EDU_EuRoC_ST_000455

Version 03, Date 04.02.2021

European Rocketry Challenge

–

Design, Test & Evaluation Guide

INTERNAL APPROVAL

PREPARED BY:

Álvaro Lopes, Portuguese Space Agency

Inês d’Ávila, Portuguese Space Agency

Manuel Wilhelm, Portuguese Space Agency

Paulo Quental, Portuguese Space Agency

Jacob Larsen, Copenhagen Suborbitals

Signature:

Date:

07/02/2022

VERIFIED BY:

Marta Gonçalves, Portuguese Space Agency

Signature:

Date: 07/02/2022

APPROVED BY:

Ricardo Conde, Portuguese Space Agency

Signature:

Date: 07/02/2022

European Rocketry Challenge

–

Design, Test & Evaluation Guide

Page 2 of 88

L 77 - 2022-23 (2. samling) - Bilag 1: Høringssvar og høringsnotat, fra uddannelses- og forskningsministeren

Portugal Space Reference PTS_EDU_EuRoC_ST_000455

Version 03, Date 04.02.2021

TABLE OF CONTENTS

LIST OF REVISIONS ....................................................................................................................... 7

1. INTRODUCTION........................................................................................................................ 8

1.1. B

ACKGROUND

.......................................................................................................................... 8

1.2. P

URPOSE

................................................................................................................................. 8

1.3. D

OCUMENTATION

................................................................................................................... 10

2. PROPULSION SYSTEMS ........................................................................................................... 10

2.1. N

TOXIC

ROPELLANTS

......................................................................................................... 10

2.2. S

OLID

OTORS

....................................................................................................................... 11

2.3. I

GNITION

YSTEMS FOR

OLID

OTORS

........................................................................................ 11

2.4. P

ROPULSION

YSTEM

AFING AND

RMING

................................................................................... 11

2.4.1. G

ROUND

START

GNITION

IRCUIT

RMING

......................................................................................... 11

2.4.2. A

START

GNITION

IRCUIT

RMING

................................................................................................. 12

2.4.3. C

LUSTERED

ROPULSION

................................................................................................................... 12

2.5. A

START

GNITION

IRCUIT

LECTRONICS

.................................................................................... 13

2.6. SRAD P

ROPULSION

YSTEMS

..................................................................................................... 13

2.6.1. C

OMBUSTION

HAMBER

RESSURE

ESTING

........................................................................................ 13

2.6.2. H

YBRID AND

IQUID

ROPULSION

ILLING

YSTEMS

............................................................................... 13

2.6.3. H

YBRID AND

IQUID

ROPULSION

YSTEM

ANKING

ESTING

.................................................................. 14

2.6.4. H

YBRID

IQUID

ENTING

.................................................................................................................. 14

2.6.5. P

ROPELLANT

FFLOADING

FTER

AUNCH

BORT

................................................................................. 15

2.6.6. S

TATIC

FIRE

ESTING

................................................................................................................. 15

3. RECOVERY SYSTEMS AND AVIONICS ....................................................................................... 15

3.1. D

UAL

EVENT

ARACHUTE AND

ARAFOIL

ECOVERY

........................................................................ 15

3.1.1. I

NITIAL

EPLOYMENT

VENT

.............................................................................................................. 16

3.1.2. M

AIN

EPLOYMENT

VENT

............................................................................................................... 16

3.1.3. E

JECTION

ROTECTION

............................................................................................................... 16

3.1.4. P

ARACHUTE

WIVEL

INKS

................................................................................................................. 16

3.1.5. P

ARACHUTE

OLORATION AND

ARKINGS

........................................................................................... 16

3.2. N

PARACHUTE

ARAFOIL

ECOVERY

YSTEMS

........................................................................... 17

3.3. R

EDUNDANT

LECTRONICS

......................................................................................................... 17

3.4. O

BOARD POWER SYSTEMS AND RAIL STANDBY TIME

...................................................................... 17

3.4.1. R

EDUNDANT

COTS R

ECOVERY

LECTRONICS

........................................................................................ 18

European Rocketry Challenge

–

Design, Test & Evaluation Guide

Page 3 of 88

L 77 - 2022-23 (2. samling) - Bilag 1: Høringssvar og høringsnotat, fra uddannelses- og forskningsministeren

Portugal Space Reference PTS_EDU_EuRoC_ST_000455

Version 03, Date 04.02.2021

3.4.2. D

ISSIMILAR

EDUNDANT

ECOVERY

LECTRONICS

................................................................................. 19

3.4.3. R

ECOVERY

LECTRONICS

CCESS

........................................................................................................ 19

3.5. O

FFICIAL

LTITUDE

OGGING AND

RACKING

YSTEM

...................................................................... 19

3.5.1. TRS F

LIGHT

OMPUTER AS

COTS F

LIGHT COMPUTER FOR

ECOVERY

....................................................... 20

3.5.2. TRS F

LIGHT

OMPUTER

REQUENCIES

................................................................................................. 20

3.5.3. TRS F

LIGHT

OMPUTER OPERATING FREQUENCY ALLOCATION

................................................................. 21

3.5.4. TRS F

LIGHT

OMPUTER FIRMWARE UPDATE

......................................................................................... 21

3.5.5. TRS

COMPATIBLE RECEIVER

(

)............................................................................................................ 21

3.5.6. TRS E

LECTRONICS

CCESS

................................................................................................................. 21

3.6. S

AFETY

RITICAL

IRING

.......................................................................................................... 22

3.6.1. C

ABLE

ANAGEMENT

....................................................................................................................... 22

3.6.2. S

ECURE

ONNECTIONS

...................................................................................................................... 22

3.6.3. C

RYO

COMPATIBLE

IRE

NSULATION

................................................................................................. 22

3.7. R

ECOVERY

YSTEM

NERGETIC

EVICES

........................................................................................ 22

3.8. R

ECOVERY

YSTEM

ESTING

....................................................................................................... 22

3.8.1. G

ROUND

EST

EMONSTRATION

........................................................................................................ 23

3.8.2. O

PTIONAL

LIGHT

EST

EMONSTRATION

............................................................................................ 23

3.8.3. O

PTIONAL

LIGHT

LECTRONICS

EMONSTRATION

................................................................................ 24

4. STORED-ENERGY DEVICES ...................................................................................................... 24

4.1. E

NERGETIC

EVICE

AFING AND

RMING

...................................................................................... 24

4.1.1. A

RMING

EVICE

CCESS

................................................................................................................... 25

4.1.2. A

RMING

EVICE

OCATION

................................................................................................................ 25

4.2. SRAD P

RESSURE

ESSELS

.......................................................................................................... 25

4.2.1. R

ELIEF

EVICE

................................................................................................................................. 26

4.2.2. D

ESIGNED

URST

RESSURE FOR

ETALLIC

RESSURE

ESSELS

............................................................... 26

4.2.3. D

ESIGNED

URST

RESSURE FOR

OMPOSITE

RESSURE

ESSELS

............................................................ 26

4.2.4. SRAD P

RESSURE

ESSEL

ESTING

....................................................................................................... 26

5. ACTIVE FLIGHT CONTROL SYSTEMS ......................................................................................... 27

5.1. R

ESTRICTED

ONTROL

UNCTIONALITY

......................................................................................... 27

5.2. U

NNECESSARY FOR

TABLE

LIGHT

............................................................................................... 27

5.3. D

ESIGNED TO

AIL

AFE

............................................................................................................ 28

5.4. B

OOST

HASE

ORMANCY

........................................................................................................ 28

5.5. A

CTIVE

LIGHT

ONTROL

YSTEM

LECTRONICS

.............................................................................. 28

5.6. A

CTIVE

LIGHT

ONTROL

YSTEM

NERGETICS

................................................................................ 29

6. AIRFRAME STRUCTURES ......................................................................................................... 29

6.1. A

DEQUATE

ENTING

................................................................................................................ 29

6.2. O

VERALL

TRUCTURAL

NTEGRITY

................................................................................................ 29

European Rocketry Challenge

–

Design, Test & Evaluation Guide

Page 4 of 88

L 77 - 2022-23 (2. samling) - Bilag 1: Høringssvar og høringsnotat, fra uddannelses- og forskningsministeren

Portugal Space Reference PTS_EDU_EuRoC_ST_000455

Version 03, Date 04.02.2021

6.2.1. M

ATERIAL

ELECTION

....................................................................................................................... 29

6.2.2. L

OAD

EARING

YEBOLTS AND

U-

BOLTS

.............................................................................................. 30

6.2.3. I

MPLEMENTING

OUPLING

UBES

....................................................................................................... 30

6.2.4. L

AUNCH

ECHANICAL

TTACHMENT

............................................................................................ 30

6.3. RF T

RANSPARENCY

.................................................................................................................. 31

6.4. I

DENTIFYING

ARKINGS

............................................................................................................ 31

6.5. O

THER

ARKINGS

................................................................................................................... 32

7. PAYLOAD ............................................................................................................................... 32

7.1. P

AYLOAD

ECOVERY

................................................................................................................ 32

7.1.1. P

AYLOAD

ECOVERY

YSTEM

LECTRONICS AND

AFETY

RITICAL

IRING

................................................ 32

7.1.2. P

AYLOAD

ECOVERY

YSTEM

ESTING

................................................................................................. 32

7.1.3. D

EPLOYABLE PAYLOAD

GPS T

RACKING

EQUIRED

................................................................................. 33

7.2. P

AYLOAD

NERGETIC

EVICES

.................................................................................................... 33

8. LAUNCH AND ASCENT TRAJECTORY REQUIREMENTS ............................................................... 33

8.1. L

AUNCH

ZIMUTH AND

LEVATION

.............................................................................................. 33

8.2. L

AUNCH

TABILITY

................................................................................................................... 33

8.3. A

SCENT

TABILITY

................................................................................................................... 34

8.4. O

VER

STABILITY

...................................................................................................................... 34

9. EUROC LAUNCH SUPPORT EQUIPMENT .................................................................................. 34

9.1. L

AUNCH

AILS

........................................................................................................................ 34

9.1.1. L

AUNCH

AIL

HECK

.................................................................................................................... 35

9.2. E

C-

PROVIDED

AUNCH

ONTROL

YSTEM

............................................................................... 36

10. TEAM-PROVIDED LAUNCH SUPPORT EQUIPMENT ................................................................. 36

10.1. E

QUIPMENT

ORTABILITY

........................................................................................................ 36

10.2. L

AUNCH

AIL

LEVATION

......................................................................................................... 36

10.3. O

PERATIONAL

ANGE

............................................................................................................. 36

10.4. F

AULT

OLERANCE AND

RMING

............................................................................................... 36

10.5. S

AFETY

RITICAL

WITCHES

...................................................................................................... 37

APPENDIX A: ACRONYMS, ABBREVIATIONS & TERMS ................................................................. 38

APPENDIX B: FIRE CONTROL SYSTEM DESIGN GUIDELINES .......................................................... 39

APPENDIX C: OFFICIAL ALTITUDE LOGGING AND TRACKING SYSTEM ........................................... 44

APPENDIX D: FLIGHT READINESS REVIEW CHECKLIST .................................................................. 68

European Rocketry Challenge

–

Design, Test & Evaluation Guide

Page 5 of 88

L 77 - 2022-23 (2. samling) - Bilag 1: Høringssvar og høringsnotat, fra uddannelses- og forskningsministeren

Portugal Space Reference PTS_EDU_EuRoC_ST_000455

Version 03, Date 04.02.2021

European Rocketry Challenge

–

Design, Test & Evaluation Guide

Page 6 of 88

L 77 - 2022-23 (2. samling) - Bilag 1: Høringssvar og høringsnotat, fra uddannelses- og forskningsministeren

Portugal Space Reference PTS_EDU_EuRoC_ST_000455

Version 03, Date 04.02.2021

LIST OF REVISIONS

EVISION

Version 01

Version 02

Version 03

ATE

20/07/2020

03/03/2021

04/02/2022

ESCRIPTION

Original edition.

Second version, major revisions for EuRoC 2021.

Third version, major revision for EuRoC 2022.

European Rocketry Challenge

–

Design, Test & Evaluation Guide

Page 7 of 88

L 77 - 2022-23 (2. samling) - Bilag 1: Høringssvar og høringsnotat, fra uddannelses- og forskningsministeren

Portugal Space Reference PTS_EDU_EuRoC_ST_000455

Version 03, Date 04.02.2021

1. INTRODUCTION

1.1. B

ACKGROUND

The Portuguese Space Agency

–

Portugal Space promotes the EuRoC

–

European Rocketry Challenge,

hosted in the Municipality of Ponte de Sor, a competition that seeks to stimulate university level

students to fly sounding rockets, by designing and building the rockets themselves. It is widely

recognized that such competitions foster innovation and motivate students to extend themselves

beyond the classroom, while learning to work as a team, solving real world problems under the same

pressures they will experience in their future careers.

EuRoC is fully aligned with the strategic goals of Portugal Space, namely the development and

evolution of the cultural/educational internationalization frameworks capable of boosting the

development of the Space sector in Portugal.

Since EuRoC’s first edition, in 2020, where 100 students

were present to 2021, with 400 students

participating, the growth of the competition within Europe is visible, and especially within Portugal,

with an increasing number of interested teams applying to the competition. For the future, it is

Portugal Space’s

goal to continue to foster the exchange of knowledge and international interaction

inherent to the event, allowing more students to gain from the Challenge and, at the same time,

contribute to it.

This document defines the rules and requirements governing participation in EuRoC. Major revisions

of this document will be accomplished by complete document reissue. Smaller revisions will be

reflected in updates to the document’s effective date and marked by the revision number. The

authority to approve and issue revised versions of this document rests with Portugal Space.

1.2. P

URPOSE

This document defines the minimum design, test and evaluation criteria that teams must meet before

launching at the competition. These criteria main goal is to promote flight safety. Departures from

the guidance this document provides may negatively impact a team’s score and flight status,

depending on the degree of severity. The foundational, qualifying criteria for EuRoC are contained in

the EuRoC Rules & Requirements document.

The following definitions differentiate between requirements and other statements. The degree to

which a team satisfies the spirit and intent of these statements will guide the competition officials’

decisions on a project’s overall score in EuRoC and flight status at the competition.

Shall

Denotes mandatory requirements.

European Rocketry Challenge

–

Design, Test & Evaluation Guide

Page 8 of 88

L 77 - 2022-23 (2. samling) - Bilag 1: Høringssvar og høringsnotat, fra uddannelses- og forskningsministeren

Portugal Space Reference PTS_EDU_EuRoC_ST_000455

Version 03, Date 04.02.2021

Failure to satisfy the spirit and intent of a mandatory requirement will always affect a project’s score

and flight status negatively.

Should

Denotes non-mandatory goals.

Failure to satisfy the spirit and intent of a non-mandatory

goal may affect a project’s score and flight

status, depending on design implementation and the team’s ability to provide thorough documentary

evidence of their due diligence on-demand.

Compliance to recommended goals and requirements may impact a team’s score and flight status in

a positive way, as demonstrating additional commitment and diligence to implement (often safety

and reliability related guidelines) is commendable.

Will

States facts and declarations of purpose.

These statements are used to clarify the spirit and intent of requirements and goals.

Flight status

Refers to the granting of permission to attempt a launch and the provisions under which that

permission remains valid.

A project’s flight status may be either nominal, provisional, or denied. The default flight status of any

team is from the project onset

“denied”, until project deliverables, and ultimately a successful Flight

Readiness Review and Flight Safety Review, convinces the technical jury to upgrade the flight status

of teams.

1) Nominal:

A project assigned nominal flight status meets or exceeds the minimum expectations of this

document and reveals no obvious flight safety concerns during flight safety review at the

competition.

2) Provisional:

A project assigned provisional flight status generally meets the minimum expectations of

this document but reveals flight safety concerns during flight safety review at the

competition which may be mitigated by field modification or by adjusting launch

environment constraints. Launch may occur only when the prescribed provisions are met.

3) Denied:

Competition officials reserve the right to deny flight status to any project which fails to

meet the minimum expectations of this document or reveals un-mitigatable flight safety

concerns during flight safety review at the competition.

European Rocketry Challenge

–

Design, Test & Evaluation Guide

Page 9 of 88

L 77 - 2022-23 (2. samling) - Bilag 1: Høringssvar og høringsnotat, fra uddannelses- og forskningsministeren

Portugal Space Reference PTS_EDU_EuRoC_ST_000455

Version 03, Date 04.02.2021

An effort is made throughout this document to differentiate between launch vehicle and payload

associated systems. Unless otherwise stated, requirements referring only to the launch vehicle do not

apply to payloads and vice versa.

1.3. D

OCUMENTATION

The following documents include standards, guidelines, schedules, or required standard forms. The

documents listed in this section (Table 1) are either applicable to the extent specified herein or contain

reference information useful in the application of this document.

Table 1: Documents file location.

OCUMENT

EuRoC Rules & Requirements

EuRoC Design, Test & Evaluation Guide

EuRoC Launch Operations

EuRoC Entry Form

EuRoC Academic Institution Letter Template

EuRoC Motors List

EuRoC Technical Questionnaire

EuRoC Temporary Admission Guide

EuRoC Waiver and Release of Liability Form

EuRoC Flight Card and Postflight Record

EuRoC Master Schedule

ILE LOCATION

http://www.euroc.pt

http://www.euroc.pt (Teams’ Reserved Area)

2. PROPULSION SYSTEMS

2.1. N

TOXIC

ROPELLANTS

Launch vehicles entering EuRoC shall use non-toxic propellants. Ammonium perchlorate composite

propellant (APCP), potassium nitrate and sugar (also known as "rocket candy"), nitrous oxide, liquid

oxygen (LOX), hydrogen peroxide, kerosene, propane, alcohol, and similar substances, are all

considered non-toxic. Toxic propellants are defined as those requiring breathing apparatus, unique

storage and transport infrastructure, extensive personal protective equipment (PPE), etc. Homemade

propellant mixtures containing any fraction of toxic propellants are also prohibited.

European Rocketry Challenge

–

Design, Test & Evaluation Guide

Page 10 of 88

L 77 - 2022-23 (2. samling) - Bilag 1: Høringssvar og høringsnotat, fra uddannelses- og forskningsministeren

Portugal Space Reference PTS_EDU_EuRoC_ST_000455

Version 03, Date 04.02.2021

2.2. S

OLID

OTORS

Only COTS solid motors from the official EuRoC motor list (issued separately) are permitted at EuRoC.

The motors must be ordered via the official EuRoC pyrotechnics. Teams should refrain from contacting

any other pyrotechnics suppliers on their own.

2.3. I

GNITION

YSTEMS FOR

OLID

OTORS

For all solid motors (COTS and SRAD), the use of the electronic ignition system provided by the EuRoC

organisers is mandatory.

2.4. P

ROPULSION

YSTEM

AFING AND

RMING

A propulsion system is considered armed if only one action (e.g., an ignition signal) must occur for the

propellant(s) to ignite. The "arming action" is usually something (i.e., a switch in series) that enables

an ignition signal to ignite the propellant(s). For example, a software-based control circuit that

automatically cycles through an "arm function" and an "ignition function" does not, in fact, implement

arming. In this case, the software's arm function does not prevent a single action (e.g., starting the

launch software) from causing unauthorized ignition. This problem may be avoided by including a

manual interrupt in the software program.

These requirements generally concern more complex propulsion systems (i.e., hybrid, liquid, and

multistage systems) and all team provided launch control systems. Additional requirements for team

provided launch control systems are defined in Section 10. of this document.

2.4.1. G

ROUND

START

GNITION

IRCUIT

RMING

All ground-started propulsion system ignition circuits/sequences shall not be "armed" until all

personnel are at least 15 m away from the launch vehicle. The provided launch control system satisfies

this requirement by implementing a removable "safety jumper" in series with the pad relay box's

power supply. The removal of this single jumper prevents firing current from being sent to any of the

launch rails associated with that pad relay box. Furthermore, access to the socket allowing insertion

of the jumper is controlled via multiple physical locks to ensure that all parties have positive control

of their own safety.

European Rocketry Challenge

–

Design, Test & Evaluation Guide

Page 11 of 88

L 77 - 2022-23 (2. samling) - Bilag 1: Høringssvar og høringsnotat, fra uddannelses- og forskningsministeren

Portugal Space Reference PTS_EDU_EuRoC_ST_000455

Version 03, Date 04.02.2021

2.4.2. A

START

GNITION

IRCUIT

RMING

All upper stage (i.e., air-start) propulsion systems shall be armed by launch detection (e.g.,

accelerometers, zero separation force [ZSF] electrical shunt connections, break-wires, or other similar

methods). Regardless of implementation, this arming function will prevent the upper stage from

arming in the event of a misfire.

2.4.3. C

LUSTERED

ROPULSION

Partial ignition may occur in clustered propulsion systems, leading to an increased probability of

incident occurrence, mainly by three potential consequences:

1. The thrust force is lower than expected, thus acceleration on the launch rail and resulting

launch rail take-off velocity too low, leading to an unstable flight.

2. The thrust force asymmetric, leading to a sideways momentum on the rocket off the launch

rail, thus to an unstable flight, and potentially a structural failure.

3. Incompletely ignited propulsions systems separate from the vehicle, ignite in the air, or ignite

from the top, and burning parts impact the ground.

To ensure stable flight, all clustered vehicles shall have a launch release system ensuring lift-off only

occurs if a minimum threshold force is met. This can be done for example by implementing a

breakaway coupling, a structural fuse, or a rope with defined breaking force.

An electromechanical alternative to a structural fuse is to measure the thrust of the restrained flight

vehicle and then open a quick release mechanism if certain conditions are fulfilled. For example, as

the vehicle throttles up, a squib/pyro actuated quick release latch can be electrically fired (i.e., Sweeny

quick release latch) when the thrust has continuously exceeded a minimum threshold for perhaps 200

milliseconds (jerk and noise suppression).

Figure 1: Example of a Sweeny quick release latch.

(Source: Matt Sweeney SPFX Inc.)

European Rocketry Challenge

–

Design, Test & Evaluation Guide

Page 12 of 88

L 77 - 2022-23 (2. samling) - Bilag 1: Høringssvar og høringsnotat, fra uddannelses- og forskningsministeren

Portugal Space Reference PTS_EDU_EuRoC_ST_000455

Version 03, Date 04.02.2021

To measure the thrust, a strain gauge could be used, or alternatively piezo-electric pressure sensors

can be applied to measure the combustion pressure inside a thrust chamber, verifying that nominal

thrust has been achieved before the quick release squib is fired. If the latter method with pressure

sensors is used, the sensor/transducer shall be of stainless-steel and mounted in a way so that it

remains protected from hot combustion gases by means of an oil trap.

Furthermore, all clustered vehicles shall provide an engineering proof (e.g., analysis and/or simulation)

that stable flight is ensured for a lift-off force above the threshold force, even if the propulsion system

fires asymmetrically (if applicable).

For

vehicles with a “main” and several “secondary” propulsion systems, the arming function of the

secondary propulsion systems shall be armed by launch detection (i.e., air-start), preventing ground

arming of the clustered propulsion in event of misfire.

2.5. A

START

GNITION

IRCUIT

LECTRONICS

All upper stage ignition systems shall comply with same requirements and goals for "redundant

electronics" and "safety critical wiring" as recovery systems

—

understanding that in this case

"initiation" refers to upper stage ignition rather than a recovery event. These requirements and goals

are defined in Sections 3.3. and 3.4. respectively.

2.6. SRAD P

ROPULSION

YSTEMS

Teams shall comply with all rules, regulations, and best practices imposed by the authorities at their

chosen test location(s). The following requirements concern verification testing of student researched

and developed (SRAD) and modified commercial-off-the-shelf (COTS) propulsion systems.

2.6.1. C

OMBUSTION

HAMBER

RESSURE

ESTING

SRAD and modified COTS propulsion system combustion chambers shall be designed and tested

according to the SRAD pressure vessel requirements defined in Section 4.2.. Note that combustion

chambers are exempted from the requirement for a relief device.

2.6.2. H

YBRID AND

IQUID

ROPULSION

ILLING

YSTEMS

Team shall demonstrate that the filling/loading/unloading of the liquid fuels can be done to be ready

for the launch window (maximum 90 minutes for liquid propellant loading, including pressurization).

European Rocketry Challenge

–

Design, Test & Evaluation Guide

Page 13 of 88

L 77 - 2022-23 (2. samling) - Bilag 1: Høringssvar og høringsnotat, fra uddannelses- og forskningsministeren

Portugal Space Reference PTS_EDU_EuRoC_ST_000455

Version 03, Date 04.02.2021

Teams utilising liquid propellants with low boiling point are also strongly encouraged to consider

abandoning the use of “passive” or “self-pressurization” of propellants and adopt active external or

internal pressurization (nitrogen or helium). Besides removing the significant propellant density

uncertainties of two-phase flows (a volatile and somewhat arbitrary mixture of gas bubbles and liquid)

in injectors, the flight vehicle can be pressurized in typically less than 15 seconds, at any point in time

after having been loaded on the launch rail.

If teams utilise any kind of remote-controlled loading mechanism for gases or liquid propellants, the

loading mechanism shall feature a clearly marked and labelled, single action, hand actuated,

“Emergency Release Mechanism”, just in case a remote-controlled

release mechanism jams and

requires manual LCO assistance.

It is strongly recommended that the flight vehicle is designed such that any filling/loading/unloading

connections for fluid propellants are readily accessible from the ground. No propellant loading

procedure should necessitate ladders or other elevation devices. Furthermore, teams should account

for a “failed” launch and subsequent unloading in launch preparation, thus teams should ensure the

availability of additional propellants, igniters, and any other parts that might need replacement or

adjustment in case a second launch attempt would be possible.

2.6.3. H

YBRID AND

IQUID

ROPULSION

YSTEM

ANKING

ESTING

SRAD and modified COTS propulsion systems using liquid propellant(s) shall successfully (without

significant anomalies) have completed a propellant loading and off-loading test in

"launchconfiguration", prior to the rocket being brought to the competition. This test may be

conducted using either actual propellant(s) or suitable proxy fluids, with the test results to be

considered a mandatory deliverable and an annex to the Technical Report, in the form of a loading

and off-loading checklist, complete with dates, signatures (at least three) and a statement of a

successful test. Referring to Section 2.4.3., it is highly recommended to perform this test multiple times

as a part of the “all-up static engine test” configuration, described in that section.

The described annex may be amended to the Technical Report, as results become available, up to the

day final deadline for delivery of the Technical Report. Failure to deliver this annex will automatically

result in a “denied” flight status.

Loading and unloading of liquid propellants must be a well-drilled, safe and efficient operation at the

competition launch rails.

2.6.4. H

YBRID

IQUID

ENTING

For hybrid and liquid motors, it is imperative that teams can facilitate oxidizer tank venting to prevent

over-pressure situations. Teams will only be able to launch in specific time slots, so pressure relief

European Rocketry Challenge

–

Design, Test & Evaluation Guide

Page 14 of 88

L 77 - 2022-23 (2. samling) - Bilag 1: Høringssvar og høringsnotat, fra uddannelses- og forskningsministeren

Portugal Space Reference PTS_EDU_EuRoC_ST_000455

Version 03, Date 04.02.2021

measures must be implemented to account for rockets potentially sitting a long time in waiting on the

launch rail. At no time oxidizer tanks must become safety liabilities.

2.6.5. P

ROPELLANT

FFLOADING

FTER

AUNCH

BORT

Hybrid and liquid propulsion systems shall implement a means for remotely controlled venting or

offloading of all liquid and gaseous propellants in the event of a launch abort.

2.6.6. S

TATIC

FIRE

ESTING

SRAD propulsion systems shall successfully (without significant anomalies) complete an instrumented

(chamber pressure and/or thrust), full scale (including system working time) static hot-fire test prior

to EuRoC. In the case of solid rocket motors, this test needs not to be performed with the same motor

casing and/or nozzle components intended for use at the EuRoC (i.e., teams must verify their casing

design, but are not forced to design reloadable/reusable motor cases).

The test shall, to the extent possible, be conducted as an “all-up static engine test”, which means that

the completed flight vehicle, rigidly fastened to a suitable test stand in an upright position, should be

tested for a full duration burn under the most realistic settings possible. Test results from horizontal

tests, using flight components is less optimum, whereas test results from test benches (not using flight

components) do not qualify.

The test results and a statement of a successful test, complete with dates and signatures (at least

three) are considered a mandatory deliverable and an annex to the Technical Report.

The described annex may be amended to the Technical Report, as results become available, up to the

day final deadline for delivery of the Technical Report. Failure to deliver this annex will automatically

result in a “denied” flight status.

“Test as you fly – Fly as you test”. This test-mentality

significantly increases the chances of a lift-off

and a nominal flight.

3. RECOVERY SYSTEMS AND AVIONICS

3.1. D

UAL

EVENT

ARACHUTE AND

ARAFOIL

ECOVERY

Each independently recovered launch vehicle body, anticipated to reach an apogee above 450 m

above ground level (AGL), shall follow a "dual-event" recovery operations concept, including an initial

deployment event (e.g., a drogue parachute deployment; reefed main parachute deployment or

similar) and a main deployment event (e.g., a main parachute deployment; main parachute un-reefing

or similar). Independently recovered bodies, whose apogee is not anticipated to exceed 450 m AGL,

are exempt and may feature only a single/main deployment event.

European Rocketry Challenge

–

Design, Test & Evaluation Guide

Page 15 of 88

L 77 - 2022-23 (2. samling) - Bilag 1: Høringssvar og høringsnotat, fra uddannelses- og forskningsministeren

Portugal Space Reference PTS_EDU_EuRoC_ST_000455

Version 03, Date 04.02.2021

3.1.1. I

NITIAL

EPLOYMENT

VENT

The initial deployment event shall occur at or near apogee, stabilize the vehicle's attitude (i.e., prevent

or eliminate tumbling), and reduce its descent rate sufficiently to permit the main deployment event,

yet not so much as to exacerbate wind drift. Any part, assembly or device, featuring an initial

deployment event, shall result in a descent velocity of said item of 23-46 m/s.

3.1.2. M

AIN

EPLOYMENT

VENT

The main deployment event shall occur at an altitude no higher than 450 m AGL and reduce the

vehicle's descent rate sufficiently to prevent excessive damage upon impact with ground. Any part,

assembly or device, featuring a main deployment event, shall result in a descent velocity of said item

of less than 9 m/s.

3.1.3. E

JECTION

ROTECTION

The recovery system shall implement adequate protection (e.g., fire-resistant material, pistons, baffles

etc.) to prevent hot ejection gases (if implemented) from causing burn damage to retaining chords,

parachutes, and other vital components as the specific design demands.

3.1.4. P

ARACHUTE

WIVEL

INKS

The recovery system rigging (e.g., parachute lines, risers, shock chords, etc.) shall implement swivel

links at connections to relieve torsion, as the specific design demands. This will mitigate the risk of

torque loads unthreading bolted connections during recovery as well as parachute lines twisting up.

3.1.5. P

ARACHUTE

OLORATION AND

ARKINGS

When separate parachutes are used for the initial and main deployment events, these parachutes

should be visually highly dissimilar from one another. This is typically achieved by using parachutes

whose primary colours contrast those of the other chute. This will enable ground-based observers to

characterize deployment events more easily with high-power optics.

Utilised parachutes should use colours providing a clear contrast to a blue sky and a grey/white cloud

cover.

European Rocketry Challenge

–

Design, Test & Evaluation Guide

Page 16 of 88

L 77 - 2022-23 (2. samling) - Bilag 1: Høringssvar og høringsnotat, fra uddannelses- og forskningsministeren

Portugal Space Reference PTS_EDU_EuRoC_ST_000455

Version 03, Date 04.02.2021

3.2. N

PARACHUTE

ARAFOIL

ECOVERY

YSTEMS

Teams exploring other recovery methods (i.e., non-parachute or parafoil based) shall mention them

in the dedicated field of the Technical Questionnaire (see Section 9.1. of the EuRoC Rules &

Requirements document). The organisers may make additional requests for information and draft

unique requirements depending on the team's specific design implementation.

3.3. R

EDUNDANT

LECTRONICS

Launch vehicles shall implement redundant recovery system electronics, including sensors/flight

computers and "electric initiators"

—

assuring initiation by a backup system, with a separate power

supply (i.e., battery), if the primary system fails. In this context, electric initiators are the devices

energized by the sensor electronics, which then initiates some other mechanical or chemical energy

release, to deploy its portion of the recovery system (i.e., electric matches, nichrome wire, flash bulbs,

etc.).

3.4. O

BOARD POWER SYSTEMS AND RAIL STANDBY TIME

Loss of launch slots have been experienced on multiple occasions as onboard batteries are typically

located in inaccessible positions. Despite the requirement of at least six hours of battery life on the

launch rail, an unsuccessful launch attempt typically results in the teams deciding to:

•

Disarm any energetic pyrotechnics;

Take the flight vehicle off the launch rail;

Haul the rocket back to the team’s preparation area;

Use tools to perform medium to extensive disassembly of the flight vehicle to extract

batteries;

Spend one to several hours recharging the batteries, if charged spares are not readily

available;

Perform the whole operation in reverse and return to the launch rail many hours later, to

perform an additional launch attempt, if the possibility is given.

This is a critically inefficient use of valuable and limited launch campaign time.

Teams should adopt one of the following two strategies:

•

Implement an on-board charging and charge level maintenance system using an umbilical

connection and cable;

European Rocketry Challenge

–

Design, Test & Evaluation Guide

Page 17 of 88

L 77 - 2022-23 (2. samling) - Bilag 1: Høringssvar og høringsnotat, fra uddannelses- og forskningsministeren

Portugal Space Reference PTS_EDU_EuRoC_ST_000455

Version 03, Date 04.02.2021

•

Place all rechargeable or replaceable batteries conveniently under service panels accessible

from ground level, without resorting to ladders or lowering the launch rail, having several

spare sets of charged batteries ready at any time.

The implementation of an on-board charging and charge level maintenance system, based on a

vehicle-wide charging bus and an umbilical cable (featuring friction-based pull-release), connected to

a ground-based power supply, should be designed/implemented as follows:

•

A “charging bus” should run along the

entire length of the flight vehicle, interfacing to all

batteries to facilitate charging and continuous charging and subsequent maintenance

tricklecharging;

Use mating connectors at every structural joint;

•

Largely all benefits of the system are lost if even a single battery is left out of the

umbilical charging bus system.

Each tap-off from the on-board charging bus to individual battery subsystems shall be reverse

current flow protected by a suitably rated diode;

All on-board batteries should feature the same nominal voltage, as far as possible;

If bus

voltage step-down is required for batteries with lower nominal voltage, adequately heat-

dissipated linear regulators are strongly recommended and placed upstream of the

mandatory cell balancing circuits;

Switch-mode regulation or onboard battery chargers are strongly discouraged due to

generated EMI and electrical noise;

LiPo battery cell balancing circuits shall protect each individual battery pack;

LiPo

battery cell balancing circuits of up to 12S cell count are widely available as

preassembled PCBs for a low price, complete with built-in undervoltage-cut-off,

overcurrent-protection and overcharging cut-off;

Flight vehicle batteries could all be considered “permanently” installed, not requiring

removal past initial installation during on-site preparation. The ground-based power

supply should simply be outputting the battery trickle charge voltage, plus a diode

drop, for easiest implementation.

The advantages of implementing such a system are in most cases worth the efforts. Most significantly,

the launch vehicle rail standby time changes to “infinite” and the launch vehicle is always launched

with 100% peak charged batteries.

3.4.1. R

EDUNDANT

COTS R

ECOVERY

LECTRONICS

At least one redundant recovery system electronics subsystem shall implement a COTS flight computer

(e.g., StratoLogger, G-Wiz, Raven, Parrot, Eggtimer, AIM, EasyMini, TeleMetrum, RRC3, etc.).

To be considered COTS, the flight computer (including flight software) must have been developed and

validated by a commercial third party. While commercially designed flight computer “kits” (e.g., the

Eggtimer) are permitted and considered COTS, any student developed flight computer assembled from

European Rocketry Challenge

–

Design, Test & Evaluation Guide

Page 18 of 88

L 77 - 2022-23 (2. samling) - Bilag 1: Høringssvar og høringsnotat, fra uddannelses- og forskningsministeren

Portugal Space Reference PTS_EDU_EuRoC_ST_000455

Version 03, Date 04.02.2021

separate COTS components will not be considered a COTS system. Similarly, any COTS microcontroller

running student developed flight software will not be considered a COTS system.

The interconnection redundancy of the nominal and redundant recovery electronics and recovery

systems should be implemented as illustrated in Figure 2.

Figure 2: Interconnection redundancy implementation. (Source: Jacob Larsen)

3.4.2. D

ISSIMILAR

EDUNDANT

ECOVERY

LECTRONICS

There is no requirement that the redundant/backup system be dissimilar to the primary; however,

there are advantages to using dissimilar primary and backup systems. Such configurations are less

vulnerable to any inherent environmental sensitivities, design, or production flaws affecting a

particular component.

3.4.3. R

ECOVERY

LECTRONICS

CCESS

As for all electronics, it is highly recommended to ensure easy and quick access to switches/connectors

via an access panel on the airframe. Access panels should be positioned so they are reachable from

ground level, ideally without ladders. Access panels shall be secured for flight.

3.5. O

FFICIAL

LTITUDE

OGGING AND

RACKING

YSTEM

Single-stage flight vehicles and upper-most stages of flight vehicles shall feature a mandatory

operational Eggtimer TRS Flight Computer for official altitude logging and GPS tracking. For more

details see http://eggtimerrocketry.com/.

The competition achieved apogee will be determined from this device.

Note:

Deployable payloads and lower stages also require a mandatory Eggfinder GPS tracking device,

but this need not be the TRS Flight Computer.

European Rocketry Challenge

–

Design, Test & Evaluation Guide

Page 19 of 88

L 77 - 2022-23 (2. samling) - Bilag 1: Høringssvar og høringsnotat, fra uddannelses- og forskningsministeren

Portugal Space Reference PTS_EDU_EuRoC_ST_000455

Version 03, Date 04.02.2021

More technical details on the Eggtimer TRS Flight Computer along with recommendations and lessons

learned can be found in Appendix C.

The Eggtimer TRS Flight Computer system serves two purposes:

•

Providing the EuRoC evaluation board with the means to easily determine and record the

apogee altitude in a fast, efficient, and consistent way. Since the flight vehicle apogee is a

fundamental part of the competition, the method of determining it must be equally fair (hence

identical) for all teams;

Provide the student/recovery teams an efficient means of quickly tracking down the location

of all landed flight vehicles (and any other tracked payload/components), to quickly clear the

launch range.

•

The Eggtimer TRS Flight Computer System was chosen to impose the least amount of inconvenience

to the teams:

•

Low weight and volume transmitter, to not impede flight vehicle design or performance;

Being cheap and imposing the smallest financial burden possible.

3.5.1. TRS F

LIGHT

OMPUTER AS

COTS F

LIGHT COMPUTER FOR

ECOVERY

The Eggtimer TRS Flight Computer may be used as the COTS flight computers to comply with the

requirements for redundant COTS Recovery Electronics according to section 3.3., or it may be used as

an additional, independent standalone system.

The Eggtimer system was NOT chosen because it provides the best overall performance or versatility.

It is however the cheapest system which fulfil the EuRoC organisation minimum functional

requirements with regards to apogee logging and GPS tracking. It is therefore recommended that

teams evaluate the specifications and functionality of the system before they decide between

implementing it as their main flight computer or leaving it as a stand-alone

“payload”.

3.5.2. TRS F

LIGHT

OMPUTER

REQUENCIES

EuRoC will make specific frequencies available for tracking system use, without the need for specific

radio amateur licenses. Eggtimer Ham-frequency equipment can thus legally be used during EuRoC

without a license. This means that all mandatory TRS Flight Computers must be purchased in the US

“Ham” frequency range.

While the “EU” license free version of the TRS sounds like a compelling option,

there is a major

drawback in the fact, that the EU license free band contains only three separate channels/frequencies,

and TRS systems cannot share the same frequency.

European Rocketry Challenge

–

Design, Test & Evaluation Guide

Page 20 of 88

L 77 - 2022-23 (2. samling) - Bilag 1: Høringssvar og høringsnotat, fra uddannelses- og forskningsministeren

Portugal Space Reference PTS_EDU_EuRoC_ST_000455

Version 03, Date 04.02.2021

This is a major problem since multiple flight vehicles might be on the launch rails at the opening of a

launch window. These vehicles will (when propulsive technology permits) be launched successively,

as soon as the previous flight vehicle is believed landed, with no time for additional pre-flight

preparations in between launches.

Therefore,

purchasing the “EU” version of the TRS Flight Computer is highly discouraged, despite being

legal to use.

3.5.3. TRS F

LIGHT

OMPUTER OPERATING FREQUENCY ALLOCATION

The EuRoC organisation intends to allocate unique TRS Flight Computer operating frequencies to

teams, at the latest shortly after the FRR. This includes the frequency for the upper-most stage of the

flight vehicle, as well as any other frequencies for lower stages and/or deployable payloads.

Teams shall however be capable of (and prepared to) re-program their operating frequencies of

Eggtimer/finder equipment at short notice in case launch schedule reshuffling requires it so.

3.5.4. TRS F

LIGHT

OMPUTER FIRMWARE UPDATE

Teams must ensure that the TRS Flight Computer is running a custom version of the firmware for the

70 cm Ham frequency band, having a channel selection resolution of 25 kHz. This is necessary in order

to be able to select the frequencies allotted to EuRoC.

Please note that firmware updates can be done at any time by participating teams, as long as the

hardware has been procured.

3.5.5. TRS

COMPATIBLE RECEIVER

(

)

While teams are not required to procure one or more receivers

for the Eggfinder “Ham-version” TRS

Flight Computer, according to the EuRoC Rules and Requirements, teams shall procure the “full kit

package”, as it includes the LCD GPS receiver.

3.5.6. TRS E

LECTRONICS

CCESS

As for all electronics, it is highly recommended to ensure easy and quick access to switches/connectors

via an access panel on the airframe. Access panels should be positioned so they are reachable from

ground level, ideally without ladders. Access panels shall be secured for flight.

European Rocketry Challenge

–

Design, Test & Evaluation Guide

Page 21 of 88

L 77 - 2022-23 (2. samling) - Bilag 1: Høringssvar og høringsnotat, fra uddannelses- og forskningsministeren

Portugal Space Reference PTS_EDU_EuRoC_ST_000455

Version 03, Date 04.02.2021

3.6. S

AFETY

RITICAL

IRING

For the purposes of this document, safety critical wiring is defined as electrical wiring associated with

recovery system deployment events and any "air started" rocket motors.

3.6.1. C

ABLE

ANAGEMENT

All safety critical wiring shall implement a cable management solution (e.g., wire ties, wiring,

harnesses, cable raceways) which will prevent tangling and excessive free movement of significant

wiring/cable lengths due to expected launch loads. This requirement is not intended to negate the

small amount of slack necessary at all connections/terminals to prevent unintentional de-mating due

to expected launch loads transferred into wiring/cables at physical interfaces.

3.6.2. S

ECURE

ONNECTIONS

All safety critical wiring/cable connections shall be sufficiently secure as to prevent de-mating due to

expected launch loads. This will be evaluated by a "tug test", in which the connection is gently but

firmly "tugged" by hand to verify it is unlikely to break free in flight.

3.6.3. C

RYO

COMPATIBLE

IRE

NSULATION

In case of propellants with a boiling point of less than -50°C any wiring or harness passing within close

proximity of a cryogenic device (e.g., valve, piping, etc.) or a cryogenic tank (e.g., a cable tunnel next

to a LOX tank) shall utilize safety critical wiring with cryo-compatible insulation (i.e., Teflon, PTFE, etc.).

3.7. R

ECOVERY

YSTEM

NERGETIC

EVICES

All stored-energy devices (i.e., energetics) used in recovery systems shall comply with the energetic

device requirements defined in Section 4. of this document.

3.8. R

ECOVERY

YSTEM

ESTING

Recovery system testing has proven to be one of the most critical and at the same time

underestimated tasks. Teams are strongly encouraged to test the system back-to-back as good as they

can and implement standard procedures that they can fall back onto even during the most stressful of

launch days.

European Rocketry Challenge

–

Design, Test & Evaluation Guide

Page 22 of 88

L 77 - 2022-23 (2. samling) - Bilag 1: Høringssvar og høringsnotat, fra uddannelses- og forskningsministeren

Portugal Space Reference PTS_EDU_EuRoC_ST_000455

Version 03, Date 04.02.2021

Teams shall comply with all rules, regulations, and best practices imposed by the authorities at their

chosen test location(s). The following requirements concern verification testing of all recovery

systems.

3.8.1. G

ROUND

EST

EMONSTRATION

All recovery system mechanisms shall be successfully (without significant anomalies) tested prior to

EuRoC, either by flight testing, or through one or more ground tests of key subsystems. In the case of

such ground tests, sensor electronics will be functionally included in the demonstration by simulating

the environmental conditions under which their deployment function is triggered.

The test results and a statement of a successful test, complete with dates and signatures (at least

three) are considered a mandatory deliverable and annex to the Technical Report.

The described annex may be amended to the Technical Report, as results become available, up to the

day final deadline for delivery of the Technical Report. Failure to deliver this annex will automatically

result in a “denied” flight status.

Correct, reliable and repeatable recovery system performance is absolute top priority from a safety

point of view. Statistical data also concludes that namely recovery system failures are the major cause

of abnormal “landings”.

3.8.2. O

PTIONAL

LIGHT

EST

EMONSTRATION

All recovery system mechanisms shall be successfully (without significant anomalies) tested prior to

EuRoC, either by flight testing, or through one or more ground tests of key subsystems. While not

required, a flight test demonstration may be used in place of ground testing. In the case of such a flight

test, the recovery system flown will verify the intended design by implementing the same major

subsystem components (e.g., flight computers and parachutes) as will be integrated into the launch

vehicle intended for EuRoC (i.e., a surrogate booster may be used).

The test results and a statement of a successful test, complete with dates and signatures (at least

three) are considered a mandatory deliverable and annex to the Technical Report.

The described annex may be amended to the Technical Report, as results become available, up to the

day final deadline for delivery of the Technical Report. Failure to deliver this annex will automatically

result in a “denied” flight status.

Correct, reliable and repeatable recovery system performance is absolute top priority from a safety

point of view. Statistical data also concludes that namely recovery system failures are the major cause

of abnormal “landings”.

European Rocketry Challenge

–

Design, Test & Evaluation Guide

Page 23 of 88

L 77 - 2022-23 (2. samling) - Bilag 1: Høringssvar og høringsnotat, fra uddannelses- og forskningsministeren

Portugal Space Reference PTS_EDU_EuRoC_ST_000455

Version 03, Date 04.02.2021

3.8.3. O

PTIONAL

LIGHT

LECTRONICS

EMONSTRATION

Teams are encouraged to have a setup to demonstrate the electronics and recovery system working

routine in the FRR, either by a software routine that actuates the outputs of the flight computer and

using LED indicators or buzzers or by a self-developed setup. This step is not mandatory, it is instead

a recommendation for teams to detect some possible bugs and defects in their system.

4. STORED-ENERGY DEVICES

4.1. E

NERGETIC

EVICE

AFING AND

RMING

All energetics shall be “safed” until the rocket is in the launch position, at which point they may be

"armed". An energetic device is considered safed when two separate events are necessary to release

the energy of the system. An energetic device is considered armed when only one event is necessary

to release the energy. For the purpose of this document, energetics are defined as all stored-energy

devices

–

other than propulsion systems

–

that have reasonable potential to cause bodily injury upon

energy release. The following table lists some common types of stored-energy devices and overviews

and in which configurations they are considered non-energetic, safed, or armed.

Table 2: Overviews and configurations of stored-energy devices.

EVICE

LASS

ENERGETIC

Small igniters/squibs,

nichrome, wire or

similar

Very small quantities

contained in non-

shrapnel producing

devices (e.g., pyrocutters

or pyro-valves)

De-energized/relaxed

state, small devices, or

captured devices (i.e.,

no jettisoned parts)

Non-charged pressure

vessels

AFED

Large igniters with leads

shunted

Large quantities with no

igniter, shunted igniter

leads, or igniter(s)

connected to unpowered

avionics

Mechanically locked and

not releasable by a single

event

Charged vessels with two

events required to open

main valve

RMED

Large igniters with

no- shunted leads

Large quantities with

non-shunted igniter

or igniter(s)

connected to

powered avionics

Unlocked and

releasable by a single

event

Charged vessels with

one event required

to open main valve

Igniters/Squibs

Pyrogens (e.g.,

black powder)

Mechanical Devices

(e.g., powerful

springs)

Pressure Vessels

European Rocketry Challenge

–

Design, Test & Evaluation Guide

Page 24 of 88

L 77 - 2022-23 (2. samling) - Bilag 1: Høringssvar og høringsnotat, fra uddannelses- og forskningsministeren

Portugal Space Reference PTS_EDU_EuRoC_ST_000455

Version 03, Date 04.02.2021

Although these definitions are consistent with the propulsion system arming definition provided in

Section 2. of this document, this requirement is directed mainly at the energetics used by recovery

systems and extends to all other energetics used in experiments, control systems, etc. Note that while

Section 2.4.1. requires propulsion systems to be armed only after the launch rail area is evacuated to

a specified distance, this requirement permits personnel to arm other stored-energy devices at the

launch rail.

4.1.1. A

RMING

EVICE

CCESS

All energetic device arming features shall be externally accessible/controllable. This does not preclude

the limited use of access panels which may be secured for flight while the vehicle is in the launch

position.

4.1.2. A

RMING

EVICE

OCATION

All energetic device arming features shall be located on the airframe such that any inadvertent energy

release by these devices will not impact personnel arming them. For example, the arming key switch

for an energetic device used to deploy a hatch panel shall not be located at the same airframe clocking

position as the hatch panel deployed by that charge.

Furthermore, it is highly recommended that the arming mechanism is accessible from ground level,

without the use of ladders or other elevation devices, when the rocket is at a vertical orientation on

the launch rail. If this requirement is considered early in the design process, implementing the arming

devices in the lower section of the rocket is easy, while also mitigating the need for risky or hazardous

arming procedures at a height.

4.2. SRAD P

RESSURE

ESSELS

The following requirements concern design and verification testing of SRAD and modified COTS

pressure vessels. Unmodified COTS pressure vessels utilized for other than their advertised

specifications will be considered modified, and subject to these requirements. SRAD (including

modified COTS) rocket motor propulsion system combustion chambers are included as well but are

exempted from the relief device requirement.

European Rocketry Challenge

–

Design, Test & Evaluation Guide

Page 25 of 88

L 77 - 2022-23 (2. samling) - Bilag 1: Høringssvar og høringsnotat, fra uddannelses- og forskningsministeren

Portugal Space Reference PTS_EDU_EuRoC_ST_000455

Version 03, Date 04.02.2021

4.2.1. R

ELIEF

EVICE

SRAD pressure vessels shall implement a relief device, set to open at no greater than the proof

pressure specified in the following requirements. SRAD (including modified COTS) rocket motor

propulsion system combustion chambers are exempted from this requirement.

4.2.2. D

ESIGNED

URST

RESSURE FOR

ETALLIC

RESSURE

ESSELS

SRAD and modified COTS pressure vessels constructed entirely from isotropic materials (e.g., metals)

shall be designed to a burst pressure no less than 2 times the maximum expected operating pressure,

where the maximum operating pressure is the maximum pressure expected during pre-launch, flight,

and recovery operations.

4.2.3. D

ESIGNED

URST

RESSURE FOR

OMPOSITE

RESSURE

ESSELS

All SRAD and modified COTS pressure vessels either constructed entirely from non-isotropic materials

(e.g., fibre reinforced plastics; FRP; composites) or implementing composite overwrap of a metallic

vessel (i.e., composite overwrapped pressure vessels; COPV), shall be designed to a burst pressure no

less than 3 times the maximum expected operating pressure, where the maximum operating pressure

is the maximum pressure expected during pre-launch, flight, and recovery operations.

4.2.4. SRAD P

RESSURE

ESSEL

ESTING

Teams shall comply with all rules, regulations, and best practices imposed by the authorities at their

chosen test location(s). The following requirements concern design and verification testing of SRAD

and modified COTS pressure vessels. Unmodified COTS pressure vessels utilized for other than their

advertised specifications will be considered modified, and subject to these requirements. SRAD

(including modified COTS) rocket motor propulsion system combustion chambers are included as well.

4.2.4.1. P

ROOF

RESSURE

ESTING

SRAD and modified COTS pressure vessels shall be proof pressure tested successfully (without

significant anomalies) to 1.5 times the maximum expected operating pressure for no less than twice

the maximum expected system working time, using the intended flight article(s) (e.g., the pressure

vessel(s) used in proof testing must be the same one(s) flown at EuRoC). The maximum system working

time is defined as the maximum uninterrupted time duration the vessel will remain pressurized during

pre-launch, flight, and recovery operations.

The test results and a statement of a successful test, complete with dates and signatures (at least

three) are considered mandatory deliverable and annexed to the Technical Report.

European Rocketry Challenge

–

Design, Test & Evaluation Guide

Page 26 of 88

L 77 - 2022-23 (2. samling) - Bilag 1: Høringssvar og høringsnotat, fra uddannelses- og forskningsministeren

Portugal Space Reference PTS_EDU_EuRoC_ST_000455

Version 03, Date 04.02.2021

The described annex may be amended to the Technical Report, as results become available, up to the

day final deadline for delivery of the Technical Report. Failure to deliver this annex will automatically

result in a “denied” flight status.

The pressure testing is an important factor in instilling confidence in the structural strength and

integrity of the flown pressure vessels. Since liquid propellant loading onto hybrid or bi-liquid

propelled flight vehicles will in the majority of cases involve manual loading, there will be times where

ground personnel will be in close proximity with pressurized systems. It is crucial that ground

personnel safety is heightened by the use of proof pressure tested pressure vessels.

4.2.4.2. O

PTIONAL

URST

RESSURE TESTING

Although there is no requirement for burst pressure testing, a rigorous verification & validation test

plan typically includes a series of both non-destructive (i.e., proof pressure) and destructive (i.e., burst

pressure) tests. A series of burst pressure tests performed on the intended design will be viewed

favourably; however, this will not be considered an alternative to proof pressure testing of the

intended flight article.

5. ACTIVE FLIGHT CONTROL SYSTEMS

5.1. R

ESTRICTED

ONTROL

UNCTIONALITY

Launch vehicle active flight control systems shall be optionally implemented strictly for pitch and/or

roll stability augmentation, or for aerodynamic "braking". Under no circumstances will a launch vehicle

entered in EuRoC be actively guided towards a designated spatial target. The organisers may make

additional requests for information and draft unique requirements depending on the team's specific

design implementation.

5.2. U

NNECESSARY FOR

TABLE

LIGHT

Launch vehicles implementing active flight controls shall be naturally stable without these controls

being implemented (e.g., the launch vehicle may be flown with the control actuator system [CAS]

—

including any control surfaces

—

either removed or rendered inert and mechanically locked, without

becoming unstable during ascent).

European Rocketry Challenge

–

Design, Test & Evaluation Guide

Page 27 of 88

L 77 - 2022-23 (2. samling) - Bilag 1: Høringssvar og høringsnotat, fra uddannelses- og forskningsministeren

Portugal Space Reference PTS_EDU_EuRoC_ST_000455

Version 03, Date 04.02.2021

Attitude Control Systems (ACS) will serve only to mitigate the small perturbations which affect the

trajectory of a stable rocket that implements only fixed aerodynamic surfaces for stability. Stability is

defined in Section 8.3. of this document. The organisers may make additional requests for information

and draft unique requirements depending on the team's specific design implementation.

5.3. D

ESIGNED TO

AIL

AFE

Control Actuator Systems (CAS) shall mechanically lock in a neutral state whenever either an abort

signal is received for any reason, primary system power is lost, or the launch vehicle's attitude exceeds

30° from its launch elevation. Any one of these conditions being met will trigger the fail-safe, neutral

system state. A neutral state is defined as one which does not apply any moments to the launch vehicle

(e.g., aerodynamic surfaces trimmed or retracted, gas jets off, etc.).

5.4. B

OOST

HASE

ORMANCY

CAS shall mechanically lock in a neutral state until either the mission’s boost phase has ended (i.e., all

propulsive stages have ceased producing thrust), the launch vehicle has crossed the point of maximum

aerodynamic pressure (i.e., max Q) in its trajectory, or the launch vehicle has reached an altitude of

6000 m AGL. Any one of these conditions being met will permit the active system state. A neutral state

is defined as one which does not apply any moments to the launch vehicle (e.g., aerodynamic surfaces

trimmed or retracted, gas jets off, etc.).

Since all flight vehicles with Control Actuator Systems (guidance systems) are to be designed inherently

passively stable at lift-off, CAS are not needed until somewhat into the flight, performing minor course

corrections thereafter. In enforcing a boost dormancy phase, any unexpected, erratic, or faulty CAS

system behaviour will take place far from the launch rail, minimizing the chances of putting EuRoC

participants at risk near the launch rail.

5.5. A

CTIVE

LIGHT

ONTROL

YSTEM

LECTRONICS

Wherever possible, all active control systems should comply with requirements and goals for

"redundant electronics" and "safety critical wiring" as recovery systems

—

understanding that in this

case "initiation" refers CAS commanding rather than a recovery event. These requirements and goals

are defined in Sections 3.3. and Section 3.4. respectively of this document. Flight control systems are

exempt from the requirement for COTS redundancy, given that such components are generally

unavailable as COTS to the amateur high-power rocketry community.

European Rocketry Challenge

–

Design, Test & Evaluation Guide

Page 28 of 88

L 77 - 2022-23 (2. samling) - Bilag 1: Høringssvar og høringsnotat, fra uddannelses- og forskningsministeren

Portugal Space Reference PTS_EDU_EuRoC_ST_000455

Version 03, Date 04.02.2021

As for all electronics, it is highly recommended to ensure easy and quick access to switches/connectors

via an access panel on the airframe. Access panels should be positioned so they are reachable from

ground level, ideally without ladders. Access panels shall be secured for flight.

5.6. A

CTIVE

LIGHT

ONTROL

YSTEM

NERGETICS

All stored-energy devices used in an active flight control system (i.e., energetics) shall comply with the

energetic device requirements defined in Section 4. of this document.

6. AIRFRAME STRUCTURES

6.1. A

DEQUATE

ENTING

Launch vehicles shall be adequately vented to prevent unintended internal pressures developed

during flight from causing either damage to the airframe or any other unplanned configuration

changes. Typically, a 3 mm to 5 mm hole is drilled in the booster section just behind the nosecone or

payload shoulder area, and through the hull or bulkhead of any similarly isolated compartment/bay.

6.2. O

VERALL

TRUCTURAL

NTEGRITY

Launch vehicles will be constructed to withstand the operating stress and retain structural integrity

under the conditions encountered during handling as well as rocket flight. The following requirements

address some key points applicable to almost all amateur high-power rockets but are not exhaustive

of the conditions affecting each unique design. Student teams are ultimately responsible for

thoroughly understanding, analysing and mitigating their design’s unique load set.

6.2.1. M

ATERIAL

ELECTION

PVC (and similar low-temperature polymers), Public Missiles Ltd. (PML) Quantum Tube components

shall not be used in any structural (i.e., load bearing) capacity, most notably as load bearing eyebolts,

launch vehicle airframes, or propulsion system combustion chambers.

European Rocketry Challenge

–

Design, Test & Evaluation Guide

Page 29 of 88

L 77 - 2022-23 (2. samling) - Bilag 1: Høringssvar og høringsnotat, fra uddannelses- og forskningsministeren

Portugal Space Reference PTS_EDU_EuRoC_ST_000455

Version 03, Date 04.02.2021

6.2.2. L

OAD

EARING

YEBOLTS AND

U-

BOLTS

All load bearing eyebolts shall be of the closed-eye, forged type

—

NOT of the open eye, bent wire

type. Furthermore, all load bearing eyebolts and U-Bolts shall be steel or stainless steel. This

requirement extends to any bolt and eye-nut assembly used in place of an eyebolt.

6.2.3. I

MPLEMENTING

OUPLING

UBES

Airframe joints which implement "coupling tubes" should be designed such that the coupling tube

extends no less than one body calibre (1D) on either side of the joint

—

measured from the separation

plane. This rule applies both for “half” couplings (e.g., nosecone –

body tube/coupling tube) as well as

for “full” couplings (e.g., body tube –

coupling tube

–

body tube). See example in Figure 3 for clarity.

Regardless of implementation (e.g., RADAX or other join types) airframe joints need to be "stiff" (i.e.,

prevent bending).

Figure 3: Examples for coupling tubes.

6.2.4. L

AUNCH

ECHANICAL

TTACHMENT

Launch lugs (i.e., rail guides) should implement "hard points" for mechanical attachment to the launch

vehicle airframe. These hardened/reinforced areas on the vehicle airframe, such as a block of wood

installed on the airframe interior surface where each launch lug attaches, will assist in mitigating lug

"tear outs" during operations.

The aft most launch lug shall support the launch vehicle's fully loaded launch weight while vertical.

At EuRoC, competition officials will require teams to lift their launch vehicles by the rail guides and/or

demonstrate that the bottom guide can hold the vehicle's weight when vertical. This test needs to be

completed successfully before the admittance of the team to Launch Readiness Review.

European Rocketry Challenge

–

Design, Test & Evaluation Guide

Page 30 of 88

L 77 - 2022-23 (2. samling) - Bilag 1: Høringssvar og høringsnotat, fra uddannelses- og forskningsministeren

Portugal Space Reference PTS_EDU_EuRoC_ST_000455

Version 03, Date 04.02.2021

6.3. RF T

RANSPARENCY

Any internally mounted RF transmitter, receiver or transceiver, not having the applicable antenna or

antennas mounted externally on the airframe, shall employ “RF windows" in the airframe shell plating

(typically glass fibre panels), enabling RF devices with antennas mounted inside the airframe, to

transmit the signal though the airframe shell.

RF windows in the flight vehicle shell shall be a 360° circumference and be at least two body diameters

in length. The internally mounted RF antenna(s) shall be placed at the midpoint of the RF window

section, facilitating maximizing the azimuth radiation pattern.

RF transmitter, receivers or transceivers are not allowed to be mounted externally.

Please note, that even though a single downward facing antenna mounted on a stabilization fin near

the engine seems like a good way to provide nearly a 360° radiation pattern from a single antenna

without significant dead-zones. This is true at any point in time, except when the rocket engine is

active. The ionized exhaust gas from the engine is highly disruptive to RF signals, so degradation or

loss of link is to be expected.

As popular as carbon fibre is for the construction of strong and lightweight airframes, it is also

conductive and will significantly shield and/or degrade RF signals, which is unacceptable. Externally

mounted antennas often provide a more powerful and uniform radiation pattern but finds the flight

vehicle body providing RF dead zones, meaning that at least two antennas on opposite sides of the

airframe are advisable.

RF antennas shall be kept as far away as possible from wiring and metallic structural elements.

Numerous examples of poor installation practice have at a great extent ruined telemetry and link

performances. Teams are highly advised to follow best RF-practices.

6.4. I

DENTIFYING

ARKINGS

The team's Team ID (a number assigned by EuRoC prior to the competition event), project name, and

academic affiliation(s) shall be clearly identified on the launch vehicle airframe. The Team ID

especially, will be prominently displayed (preferably visible on all four quadrants of the vehicle, as well

as fore and aft), assisting competition officials to positively identify the project hardware with its

respective team throughout EuRoC.

European Rocketry Challenge

–

Design, Test & Evaluation Guide

Page 31 of 88

L 77 - 2022-23 (2. samling) - Bilag 1: Høringssvar og høringsnotat, fra uddannelses- og forskningsministeren

Portugal Space Reference PTS_EDU_EuRoC_ST_000455

Version 03, Date 04.02.2021

6.5. O

THER

ARKINGS

There are no requirements for airframe coloration or markings beyond those specified in Section 6.4.

of this document. However, EuRoC offers the following recommendations to student teams: mostly

white or lighter tinted colour (e.g., yellow, red, orange, etc.) airframes are especially conducive to

mitigating some of the solar heating experienced in the EuRoC launch environment. Furthermore,

high-visibility schemes (e.g., high-contrast black, orange, red, etc.) and roll patterns (e.g., contrasting

stripes, “V” or “Z” marks, etc.) may allow ground-based

observers to track and record the launch

vehicle’s trajectory with high-power

optics more easily.

7. PAYLOAD

7.1. P

AYLOAD

ECOVERY

Payloads may be deployable or remain attached to the launch vehicle throughout the flight.

Deployable payloads shall incorporate an independent recovery system, reducing the payload's

descent velocity to less than 9 m/s before it descends through an altitude of 450 m AGL.

All types of deployable payloads must be authorized by the EuRoC Technical Evaluation Board prior to

the EuRoC. Deployable payloads without two-stage recovery systems (drogue and main chute, like the

rockets) will be subjective to considerable drift during descent.

Note that deployable payloads implementing a parachute or parafoil based recovery system are not

required to comply with the dual-event requirements described in Section 3.1. of this document, being

allowed to utilize a single-stage 8-9m/s descent rate from apogee recovery system, subject to case-

by-case EuRoC approval (the intent being to accommodate certain science/engineering packages

requiring extended airborne mission time).

7.1.1. P

AYLOAD

ECOVERY

YSTEM

LECTRONICS AND

AFETY

RITICAL

IRING

Payloads implementing independent recovery systems shall comply with the same requirements and

goals as the launch vehicle for "redundant electronics" and "safety critical wiring". These requirements

and goals are defined in Sections 3.3. and 3.4. respectively.

7.1.2. P

AYLOAD

ECOVERY

YSTEM

ESTING

Payloads implementing independent recovery systems shall comply with the same requirements and

goals as the launch vehicle for "recovery system testing". These requirements and goals are defined

in Section 3.8..

European Rocketry Challenge

–

Design, Test & Evaluation Guide

Page 32 of 88

L 77 - 2022-23 (2. samling) - Bilag 1: Høringssvar og høringsnotat, fra uddannelses- og forskningsministeren

Portugal Space Reference PTS_EDU_EuRoC_ST_000455

Version 03, Date 04.02.2021

7.1.3. D

EPLOYABLE PAYLOAD

GPS T

RACKING

EQUIRED

It must be noted that deployable payloads are equivalent to flight vehicle bodies and sections, in that

they can be difficult to locate after landing. All deployable payloads shall feature the same mandatory

GPS tracking system as all rockets and rocket stages as specified in Section 3.5. of this document.

The GPS locator ID must differ from the ID of the launch vehicle.

7.2. P

AYLOAD

NERGETIC

EVICES

All stored-energy devices (i.e., energetics) used in payload systems shall comply with the energetic

device requirements defined in Section 4. of this document.

8. LAUNCH AND ASCENT TRAJECTORY REQUIREMENTS

8.1. L

AUNCH

ZIMUTH AND

LEVATION

Launch vehicles shall nominally launch at an elevation angle of 84° ±1° and a launch azimuth defined

by competition officials at EuRoC. Competition officials reserve the right to require certain vehicles'

launch elevation be as low as 70° if flight safety issues are identified during pre-launch activities.

The tolerance expressed within the nominal launch azimuth is intended as nothing more than an

expression of acceptable human error by the operator setting the launch rail elevation prior to launch.

8.2. L

AUNCH

TABILITY

Launch vehicles shall have sufficient velocity upon "departing the launch rail" to ensure they will follow

predictable flight paths. In lieu of detailed analysis, a rail departure velocity of at least 30 m/s is

generally acceptable. Alternatively, the team may use detailed analysis to prove stability is achieved

at a lower rail departure velocity 20 m/s either theoretically (e.g., computer simulation) or empirically

(e.g., flight testing).

Teams shall comply with all rules, regulations, and best practices imposed by the authorities at their

chosen test location(s). Departing the launch rail is defined as the first instant in which the launch

European Rocketry Challenge

–

Design, Test & Evaluation Guide

Page 33 of 88

L 77 - 2022-23 (2. samling) - Bilag 1: Høringssvar og høringsnotat, fra uddannelses- og forskningsministeren

Portugal Space Reference PTS_EDU_EuRoC_ST_000455

Version 03, Date 04.02.2021

vehicle becomes free to move about the pitch, yaw, or roll axis. This generally occurs at the instant

the last rail guide forward of the vehicle's centre of gravity (CG) separates from the launch rail.

The requirements for team provided launch rails are defined in Section 10. of this document.

8.3. A

SCENT

TABILITY

Launch vehicles shall remain "stable" for the entire ascent. Stable is defined as maintaining a static

stability margin of at least 1.5 calibres throughout the whole flight phase (upon leaving the launch

rail), regardless of CG movement due to depleting consumables and shifting centre of pressure (CP)

location due to wave drag effects (which may become significant as low as 0.5 Mach).

8.4. O

VER

STABILITY

All launch vehicles should avoid becoming "over-stable" during their ascent. A launch vehicle may be

considered over-stable with a static margin significantly greater than 2 body calibres (e.g., greater than

6 body calibres).

9. EUROC LAUNCH SUPPORT EQUIPMENT

9.1. L

AUNCH

AILS

EuRoC will provide standardised launch rails for the teams that do not intend to bring their own launch

rail. One of the EuRoC Launch rails which will generally be near the paddock during Flight Readiness

Reviews for the Launch Rail Fit Check, while three will be at the Launch Site. The vehicle is guided by

a 50 mm x 50 mm cross-section aluminium rail by Kanya (see Figure 4 for details) The launch rail length

is 12 m and the launch rail inclination usually 84±1° to vertical, which may be lowered on a case-by-

case basis if the EuRoC officials deem it necessary. For details on the launch lugs, please see Section

6.2.4..

European Rocketry Challenge

–

Design, Test & Evaluation Guide

Page 34 of 88

L 77 - 2022-23 (2. samling) - Bilag 1: Høringssvar og høringsnotat, fra uddannelses- og forskningsministeren

Portugal Space Reference PTS_EDU_EuRoC_ST_000455

Version 03, Date 04.02.2021

Figure 4: EuRoC launch rail profile.

9.1.1. L

AUNCH

AIL

HECK

All teams shall perform a “launch rail fit check” as a part of the flight preparations (the

Flight Readiness

Review), before going to the launch range. This requirement is particularly important if a team is not

bringing their own launch rail, but instead relying on EuRoC provided launch rails. Teams shall provide

their own bottom “spacer” to define their vehicles’ vertical position on the rail.

Arriving at the launch rails, only then discovering that a team's launch lugs does not fit the launch rail,

will be considered gross negligence by Mission Control and the EuRoC evaluation board. The launch

rail fit check will ensure that such surprises are not encountered on the launch rails, causing delays

and loss of launch opportunities.

Note:

The launch rail fit check can only be done in the presence of EuRoC officials. Teams cannot use

the EuRoC launch rails without permission, any launch rail related activity shall be duly authorised by

EuRoC officials.

European Rocketry Challenge

–

Design, Test & Evaluation Guide

Page 35 of 88

L 77 - 2022-23 (2. samling) - Bilag 1: Høringssvar og høringsnotat, fra uddannelses- og forskningsministeren

Portugal Space Reference PTS_EDU_EuRoC_ST_000455

Version 03, Date 04.02.2021

9.2. E

C-

PROVIDED

AUNCH

ONTROL

YSTEM

EuRoC will provide a Launch Control System. The system will be a Wilson F/X Wireless Launch Control

System or equivalent.

The Wilson F/X wireless Launch Control System with one LCU-64x launch control unit and two PBU-8w

encrypted pad relay boxes (more details on Wilson F/X Digital Launch Control Systems may be found

on the Wilson F/X website: www.wilsonfx.com).

10. TEAM-PROVIDED LAUNCH SUPPORT EQUIPMENT

10.1. E

QUIPMENT

ORTABILITY

If possible/practicable, teams should make their launch support equipment man-portable over a short

distance (a few hundred metres). Environmental considerations at the launch site permit only limited

vehicle use beyond designated roadways, campgrounds, and basecamp areas.

10.2. L

AUNCH

AIL

LEVATION

Team provided launch rails shall implement the nominal launch elevation specified in Section 8.1. of

this document and, if adjustable, not permit launch at angles either greater than the nominal elevation

or lower than 70°.

10.3. O

PERATIONAL

ANGE

All team provided launch control systems shall be electronically operated and have a maximum

operational range of no less than 650 metres from the launch rail. The maximum operational range is

defined as the range at which launch may be commanded reliably.

10.4. F

AULT

OLERANCE AND

RMING

All team provided launch control systems shall be at least single fault tolerant by implementing a

removable safety interlock (i.e., a jumper or key to be kept in possession of the arming crew during

arming) in series with the launch switch. Appendix B: Fire Control System Design Guidelines of this

document provides general guidance on assuring fault tolerance in amateur high-power rocketry

launch control systems.

European Rocketry Challenge

–

Design, Test & Evaluation Guide

Page 36 of 88

L 77 - 2022-23 (2. samling) - Bilag 1: Høringssvar og høringsnotat, fra uddannelses- og forskningsministeren

Portugal Space Reference PTS_EDU_EuRoC_ST_000455

Version 03, Date 04.02.2021

10.5. S

AFETY

RITICAL

WITCHES

All team provided launch control systems shall implement ignition switches of the momentary,

normally open (also known as "dead man") type so that they will remove the signal when released.

Mercury or "pressure roller" switches are not permitted anywhere in team provided launch control

systems.

European Rocketry Challenge

–

Design, Test & Evaluation Guide

Page 37 of 88

L 77 - 2022-23 (2. samling) - Bilag 1: Høringssvar og høringsnotat, fra uddannelses- og forskningsministeren

Portugal Space Reference PTS_EDU_EuRoC_ST_000455

Version 03, Date 04.02.2021

APPENDIX A: ACRONYMS, ABBREVIATIONS & TERMS

AGL

APCP

APRS

ANAC

CONOPS

COTS

DTEG

EuRoC

ESRA

FRR

GNSS

GPS

HPR

IREC

LRR

LOX

SAC

SRAD

TBD

TBR

TBC

TEB

Actual Apogee

Above Ground Level

Ammonium Perchlorate Composite Propellant

Automatic Packet Reporting System

Portugal’s

National Civil Aviation Authority

Concept of Operations

Commercial of-the-shelf

Design, Test and Evaluation Guide

European Rocketry Challenge

Experimental Sounding Rocket Association

Flight Readiness Review

Global Navigation Satellite System

Global Positioning System

Hybrid

High Power Rocket

Intercollegiate Rocket Engineering Competition

Liquid

Launch Readiness Review

Liquid Oxygen

Points

Radio Frequency

Solid

Spaceport America Cup

Student Researched & Developed

Target Apogee

To be determined or defined

To be resolved

To be confirmed

Technical Evaluation Board

European Rocketry Challenge

–

Design, Test & Evaluation Guide

Page 38 of 88

L 77 - 2022-23 (2. samling) - Bilag 1: Høringssvar og høringsnotat, fra uddannelses- og forskningsministeren

Portugal Space Reference PTS_EDU_EuRoC_ST_000455

Version 03, Date 04.02.2021

ACS

AGL

APCP

APRS

ANAC

CAS

CONOPS

COPV

COTS

DTEG

EuRoC

ESRA

FRP

GPS

HPR

IREC

LOX

PPE

SRAD

TBD

TBR

Unit, as in Cube-Sat unit

Attitude Control Systems

Above Ground Level

Ammonium Perchlorate Composite Propellant

Automatic Packet Reporting System

Portugal´s National Civil Aviation Authority

Control Actuator System

Concept of Operations

Composite Overwrapped Pressure Vessels

Commercial of-the-shelf

Design, Test and Evaluation Guide

European Rocketry Challenge

Experimental Sounding Rocket Association

Fibre Reinforced Plastics

Global Positioning System

High Power Rocket

Intercollegiate Rocket Engineering Competition

Liquid Oxygen

Personal Protective Equipment

Student Researched & Developed

To be determined or defined

To be resolved

APPENDIX B: FIRE CONTROL SYSTEM DESIGN GUIDELINES

B.1. I

NTRODUCTION

The following white paper is written to illustrate safe fire control system design best practices and

philosophy to student teams participating in the IREC. When it comes to firing (launch) systems for

large amateur rockets, safety is paramount. This is a concept that everyone agrees with, but it is

apparent that few truly appreciate what constitutes a “safe” firing system. Whether they have ever

seen it codified or not, most rocketeers understand the basics:

European Rocketry Challenge

–

Design, Test & Evaluation Guide

Page 39 of 88

L 77 - 2022-23 (2. samling) - Bilag 1: Høringssvar og høringsnotat, fra uddannelses- og forskningsministeren

Portugal Space Reference PTS_EDU_EuRoC_ST_000455

Version 03, Date 04.02.2021

•

The control console should be designed such that two deliberate actions are required to fire

the system;

The system should include a power interrupt such that firing current cannot be sent to the

firing leads while personnel are at the pad and this interrupt should be under the control of

personnel at the pad.

These are good design concepts and if everything is working as it should they result in a perfectly safe

firing system. But “everything is working as it should” is a dangerous assumption to make. Control

consoles bounce around in the backs of trucks during transport. Cables get stepped on, tripped over,

and run over. Switches get sand and grit in them. In other words, components fail. As such there is

one more concept that should be incorporated into the design of a firing system:

The failure of any single component should not compromise the safety of the firing system.

B.2. P

ROPER

IRE

ONTROL

YSTEM

ESIGN

HILOSOPHY

Let us examine a firing system that may at first glance appear to be simple, well designed, and safe

(Figure 1). If

everything is functioning as designed, this is a perfectly safe firing system, but let’s

examine the system for compliance with proper safe design practices.

The control console should be designed such that two deliberate actions are required to launch the

rocket. Check! There are actually three deliberate actions required at the control console: (1) insert

the key, (2) turn the key to arm the system, (3) press the fire button.

The system should include a power interrupt such that ignition current cannot be sent to the firing

leads while personnel are at the pad and this interrupt should be under control of personnel at the

pad. Check and check! The Firing relay effectively isolates the electric match from the firing power

supply (battery) and as the operator at the pad should have the key in his pocket, there is no way that

a person at the control console can accidentally fire the rocket.

But all of this assumes that everything in the firing system is working as it should. Are there any single

component failures that can cause a compromise in the safety of this system? Yes. In a system that

only has five components beyond the firing lines and e-match, three of those components can fail with

potentially lethal results.

European Rocketry Challenge

–

Design, Test & Evaluation Guide

Page 40 of 88

L 77 - 2022-23 (2. samling) - Bilag 1: Høringssvar og høringsnotat, fra uddannelses- og forskningsministeren

Portugal Space Reference PTS_EDU_EuRoC_ST_000455

Version 03, Date 04.02.2021

Figure 5: A simple high current fire control system.

Firing Relay: If the firing relay was stuck in the ON position: The rocket would fire the moment it was

hooked to the firing lines. This is a serious safety failure with potentially lethal consequences as the

rocket would be igniting with pad personnel in immediate proximity.

Arming Switch: If the arm key switch failed in the ON position simply pushing the fire button would

result in a fired rocket whether intentional or not. This is particularly concerning as the launch key

–

intended as a safety measure controlled by pad personnel

–

becomes utterly meaningless. Assuming

all procedures were followed, the launch would go off without a hitch. Regardless, this is a safety

failure as only one action (pressing the fire button) would be required at the control console to launch

the rocket. Such a button press could easily happen by accident. If personnel at the pad were near the

rocket at the time we are again dealing with a potentially lethal outcome

CAT5 Cable: If the CAT5 cable was damaged and had a short in it the firing relay would be closed and

the rocket would fire the moment it was hooked to the firing lines. This too is a potentially lethal safety

failure.

Notice that all three of these failures could result in the rocket being fired while there are still

personnel in immediate proximity to the rocket. A properly designed firing system does not allow

single component failures to have such drastic consequences. Fortunately, the system can be fixed

with relative ease.

Consider the revised system (Figure 6). It has four additional features built into it:

(1) a separate battery to power the relay (as opposed to relying on the primary battery at the pad),

(2) a flip cover over the fire button,

(3) a lamp/buzzer in parallel with the firing leads (to provide a visual/auditory warning in the event

that voltage is present at the firing lines), and

(4) a switch to short-out the firing leads during hook up (pad personnel should turn the shunt switch

ON anytime they approach the rocket).

European Rocketry Challenge

–

Design, Test & Evaluation Guide

Page 41 of 88

L 77 - 2022-23 (2. samling) - Bilag 1: Høringssvar og høringsnotat, fra uddannelses- og forskningsministeren

Portugal Space Reference PTS_EDU_EuRoC_ST_000455

Version 03, Date 04.02.2021

Figure 6: An improved high current fire control system.

In theory, these simple modifications to the previous firing circuit have addressed all identified single

point failures in the system. The system has 8 components excluding the firing lines and e-match (part

of the rocket itself). Can the failure of any of these components cause an inadvertent firing? That is

the question. Let us examine the consequences of the failure of each of these components.

Fire Button: If the fire button fails in the ON position, there are still two deliberate actions at the

control console required to fire the rocket. (1) The key must be inserted into the arming switch, and

(2) the key must be rotated. The firing will be a bit of a surprise, but it will not result in a safety failure

as all personnel should have been cleared by the time possession of the key is transferred to the Firing

Officer.

Arm Switch: If the arm switch were to fail in the ON position, there are still two deliberate actions at

the control console required to fire the rocket. (1) The cover over the fire button would have to be

removed, and (2) the fire button would have to be pushed. This is not an ideal situation as the system

would appear to function flawlessly even though it is malfunctioning and the key in the possession of

personnel at the launch pad adds nothing to the safety of the overall system. It is for this reason that

the shunting switch should be used. Use of the shunting switch means that any firing current would

be dumped through the shunting switch rather than the e-match until the pad personnel are clear of

the rocket. Thus, personnel at the pad retain a measure of control even in the presence of a

malfunctioning arming switch and grossly negligent use of the control console.

Batteries: If either battery (control console or pad box) fails, firing current cannot get to the e-match

either because the firing relay does not close or because no firing current is available. No fire means

no safety violation.

CAT5 Cable: If the CAT5 cable were to be damaged and shorted, the system would simply not work as

current intended to pull in the firing relay would simply travel through the short. No fire means no

safety violation.

Firing Relay: If the firing relay fails in the ON position the light/buzzer should alert the pad operator of

the failure before he even approaches the pad to hook up the e-match.

European Rocketry Challenge

–

Design, Test & Evaluation Guide

Page 42 of 88

L 77 - 2022-23 (2. samling) - Bilag 1: Høringssvar og høringsnotat, fra uddannelses- og forskningsministeren

Portugal Space Reference PTS_EDU_EuRoC_ST_000455

Version 03, Date 04.02.2021

Shunt switch, Lamp/Buzzer: These are all supplementary safety devices. They are intended as added

layers of safety to protect and/or warn of failures of other system components. Their correct (or

incorrect) function cannot cause an inadvertent firing.

Is this a perfect firing system? No. There is always room for improvement. Lighted switches or similar

features could be added to provide feedback on the health of all components. Support for firings at

multiple launch pads could be included. Support for the fuelling of hybrids and/or liquids could be

required. A wireless data link could provide convenient and easy to set up communications at greater

ranges. The list of desired features is going to be heavily situation dependent and is more likely to be

limited by money than good ideas.

Hopefully the reader is getting the gist: The circuit should be designed such that no single equipment

failure can result in the inadvertent firing of the e-match and thus, the rocket motor. Whether or not

a particular circuit is applicable to any given scenario is beside the larger point that in the event of any

single failure a firing system should always fail safe and never fail in a dangerous manner. No matter

how complicated the system may be, it should be analysed in depth and the failure of any single

component should never result in the firing of a rocket during an unsafe range condition. Note that

this is the bare minimum requirement; ideally, a firing system can handle multiple failures in a safe

manner.

European Rocketry Challenge

–

Design, Test & Evaluation Guide

Page 43 of 88

L 77 - 2022-23 (2. samling) - Bilag 1: Høringssvar og høringsnotat, fra uddannelses- og forskningsministeren

Portugal Space Reference PTS_EDU_EuRoC_ST_000455

Version 03, Date 04.02.2021

APPENDIX C: OFFICIAL ALTITUDE LOGGING AND TRACKING SYSTEM

C.1. I

NTRODUCTION

This appendix contains mandatory provisions for flight vehicles partaking in the EuRoC competition.

C.1.1. S

COPE

EuRoC calls for a specific system for rocket (flight vehicle) apogee tracking and subsequent

location/recovery of landed vehicles, which this appendix focuses on.

The specific system tested and approved for these tasks is described in further detail in the technical

sections, along with recommendations and lessons learned from the test campaign at the end.

C.1.2. B

ACKGROUND

The fast growth in number of teams attending the EuRoC competition calls for some careful

considerations on how to complete the following two tasks in the most efficient and expedient way:

•

Providing the EuRoC jury with the means to easily determine and record the apogee altitude

in a fast, efficient, and consistent way. Since the flight vehicle apogee is a fundamental part of

the competition, the method of determining it must be equally fair (hence identical) for all

teams;

Provide the student/recovery teams an efficient means of quickly tracking down the location

of all landed flight vehicles (and any other tracked payload/components), to quickly clear the

launch range.

•

After careful consideration of what a future-proof solution to the above could look like, EuRoC requires

students to fly a mandatory system for altitude logging and recovery tracking.

C.1.3. R

ATIONALE

While the prime intentions behind instigating a specific mandatory altitude and logging system are

clear, the EuRoC organisation has also put some emphasis on trying to find a solution which will impose

the least amount of inconvenience (in general) on teams.

An example of trying to impose a least amount of inconvenience, for requiring the installation of a

distinct mandatory altitude logging and tracking system is, for example:

•

Low weight and volume transmitter, to not impede flight vehicle design or performance;

Being cheap and imposing the smallest financial burden possible.

European Rocketry Challenge

–

Design, Test & Evaluation Guide

Page 44 of 88

L 77 - 2022-23 (2. samling) - Bilag 1: Høringssvar og høringsnotat, fra uddannelses- og forskningsministeren

Portugal Space Reference PTS_EDU_EuRoC_ST_000455

Version 03, Date 04.02.2021

It is the EuRoC organisation main objective to seek out a universally fair and transparent method of

determining apogee, where teams may be separated by only a few meters at apogee.

Furthermore, the EuRoC organisation also focuses on finding a field-rated solution for tracking and

recovering the flight vehicles in the most efficient and expedient manner, minimising at the most the

efforts of, and time spent in the field, trying to locate and recover landed rockets.

C.2. A

LTITUDE

OGGING AND TRACKING SYSTEM FUNCTIONAL REQUIREMENTS

C.2.1. A

LTITUDE AND APOGEE REQUIREMENTS

1) The system shall be able to log and store the flight apogee in a non-volatile memory.

•

Apogee and flight data may still be recoverable after various “unforeseen events”,

such as power-outs or even crashes.

2) The system shall be able to allow the EuRoC Jury to extract the apogee and flight data, using

one fast, efficient, and standardized way, without necessarily requiring student team

assistance.

•

This means one common system across all flight vehicles, to which the Jury can

extract the needed flight data with one single tool.

3) The system should be able to provide real-time altitude read-outs during flight.

•

If this data or data stream is captured and logged, it should be possible to reconstruct

the altitude curve and the apogee, in case of a total loss of flight vehicle/data.

4) The system should be able to provide the teams and Jury with a preliminary apogee figure for

quick measure, later to be backed up by detailed recorded flight data.

C.2.2. T

RACKING AND RECOVERY REQUIREMENTS

The system shall consist of a transmitter and a receiver, and the transmitter shall record it’s

position by means of GPS and transmit its location to the receiver.

•

Both the transmitter and receiver can be transceivers;

More than one transmitter can be employed when the Rules and Regulations call for

it, as required for each stage of multi-stage flight vehicles, as well as for deployable

payloads;

More than one receiver can be employed for various purposes.

•

European Rocketry Challenge

–

Design, Test & Evaluation Guide

Page 45 of 88

L 77 - 2022-23 (2. samling) - Bilag 1: Høringssvar og høringsnotat, fra uddannelses- og forskningsministeren

Portugal Space Reference PTS_EDU_EuRoC_ST_000455

Version 03, Date 04.02.2021

2) The system shall as efficiently and directly as possible direct the operator of the receiver to

the landing coordinates of the flight vehicle. This is achieved by the receiver being aware of

the transmitters position (or last

known position), as well as the receiver’s own current

position, through GPS receivers in both devices.

•

The receiver shall be mobile and transportable (in the operational state) by a single

person, without support.

C.2.3. G

ENERAL REQUIREMENTS

1. The transmitter shall be as small and light as possible, facilitating easy integration into the

flight vehicle and exhibit the least possible mass penalty for flight vehicle mass budgets.

2. The system shall be a commercially available solution, with a history of adequate and reliable

operation, to which EuRoC can acquire and use the organisation’s own receivers.

•

Teams can fly additional high-end tracking solutions as they please, but EuRoC recovery

crews shall be able to utilize one single type of standardized and fieldprogrammable

system receiver to track and recover all flight vehicles launched.

3. The system shall be field-programmable with regards to RF operating frequency.

•

Unexpected launch slot re-shuffling may suddenly necessitate a likewise re-shuffling

of GPS tracking system operating frequencies;

“Field-programmable” may include the use of additional equipment, such as a laptop,

to accomplish the task of changing frequencies.

4. The transmitter shall be mounted internally in the flight vehicle, at the location of an

“RFtransparent” section, unless the transmitter features an externally mounted antenna.

•

No external mounting allowed.

5. The system should be capable of performing its function without the support of other services,

such as mobile cell networks, online web-services, or online apps.

•

A self-reliant, enclosed, stand-alone system is well suited for field operations, with

intermittent or lacking mobile services (where delicate laptops, wired breakout

boards, and web-based apps are not).

6. The receiver display should be clearly readable in bright sunlight.

•

Backlit screens and displays can be difficult to read under clear skies and full sun

conditions.

European Rocketry Challenge

–

Design, Test & Evaluation Guide

Page 46 of 88

L 77 - 2022-23 (2. samling) - Bilag 1: Høringssvar og høringsnotat, fra uddannelses- og forskningsministeren

Portugal Space Reference PTS_EDU_EuRoC_ST_000455

Version 03, Date 04.02.2021

7. The receiver should, to the extent possible, be ruggedized for extended periods of field use.

•

The receiver and its operator may likely experience a bumpy and dusty cross-country

excursion, while conducting the recovery effort;

The receiver should be able to operate continuously throughout a day.

8. The system should be cheap and affordable to the extent possible, where it does not impact

reliability or function.

•

Affordable and adequate performance is favoured over fancy and expensive

alternatives.

C.3. M

ANDATORY

LTITUDE

OGGING AND TRACKING SYSTEM

C.3.1. E

GGTIMER

TRS F

LIGHT

OMPUTER

Figure 7: Eggtimer TRS Flight Computer (assembled). (Source: Eggtimer)

Single-stage flight vehicles and upper-most stages of flight vehicles shall feature an operational

Eggtimer TRS Flight Computer for official altitude logging and GPS tracking.

The competition achieved apogee will be determined from this device.

Note:

Deployable payloads and lower stages also require a mandatory Eggfinder GPS tracking device,

but this need not be the TRS Flight Computer. See section C.4.5. for details.

The Eggtimer TRS (Total Recovery System) Flight Computer combines several useful systems in one

device, fulfilling the requirements outlined in section C.2.:

•

A COTS dual-channel deployment computer;

European Rocketry Challenge

–

Design, Test & Evaluation Guide

Page 47 of 88

L 77 - 2022-23 (2. samling) - Bilag 1: Høringssvar og høringsnotat, fra uddannelses- og forskningsministeren

Portugal Space Reference PTS_EDU_EuRoC_ST_000455

Version 03, Date 04.02.2021

•

Barometric pressure sensor for apogee determination and recovery systems deployment;

A non-volatile memory for recording flight data (including altitude) over the full flight

duration.

GPS tracking functionality and a tracking transmitter.

The TRS Flight Computer comes as a kit (PCB, components and some sub-assemblies) and requires

component mounting and testing.

C.3.1.1. TRS F

LIGHT

OMPUTER FIRMWARE UPDATE

Teams must ensure that the TRS Flight Computer is running a custom version of the firmware for the

70 cm Ham frequency band, having a channel selection resolution of 25 kHz. This is necessary in order

to be able to select the frequencies allotted to EuRoC.

Please note that firmware updates can be done at any time by participating teams, as long as the

hardware has been procured.

See section C.4. for further details on firmware.

C.3.1.2. T

TRS F

LIGHT

OMPUTER IS ELIGIBLE AS THE REDUNDANT

COTS

DEPLOYMENT ELECTRONICS

As per the “Redundant COTS Recovery Electronics” section in the EuRoC Design Guide, the TRS Flight

Computer fulfils this requirement and can be used as the redundant recovery system electronics

subsystem.

C.3.1.3. TRS F

LIGHT

OMPUTER OPERATING FREQUENCY ALLOCATION

The EuRoC organisation will allocate TRS Flight Computer operating frequencies to teams no less than

24 hours prior to the Flight Readiness Review. This includes the frequency for the upper-most stage of

the flight vehicle, as well as any other frequencies for lower stages and/or deployable payloads.

Teams must however be capable of (and prepared to) re-program their operating frequencies of

Eggtimer/finder equipment at short notice in case launch schedule reshuffling requires it so.

C.3.1.4. E

C M

ISSION CONTROL

GGFINDER

LCD

HANDHELD RECEIVERS

The EuRoC organisation will field a selection of fully upgraded Eggfinder LCD handheld receivers, to be

placed at Mission Control for the duration of the launch campaign:

•

Four units of Ham-version LCD handheld receivers with LCD-GPS and custom field-use

enclosure upgrade;

European Rocketry Challenge

–

Design, Test & Evaluation Guide

Page 48 of 88

L 77 - 2022-23 (2. samling) - Bilag 1: Høringssvar og høringsnotat, fra uddannelses- og forskningsministeren

Portugal Space Reference PTS_EDU_EuRoC_ST_000455

Version 03, Date 04.02.2021

•

One unit of EU license free version LCD handheld receiver with LCD-GPS and custom field-use

enclosure upgrade.

Up to five of these LCD handheld receivers will be tuned to the individual TRS Flight Computer

transmission frequencies of the flight vehicles scheduled for launch, at each launch slot.

As each rocket launches, each of the EuRoC operated tuned LCD receivers may be connected to a

tripod with high gain directional antennas at mission control. The aim is to receive live telemetry and

altitude data even at 9 km altitude and track the flight vehicle until loss of line-of-sight at very low

altitude. The procedure is predicted to be as follows:

•

Mission Control will know the flight vehicle assigned operating frequency (or frequencies) and

program the EuRoC operated LCD receivers during launch preparations;

The reception of valid TRS Flight Computer telemetry will be verified prior to (or during) the

Launch Readiness Review, performed at the launch rail;

Mission Control will track the TRS Flight Computer of each flight vehicle during the entire

flight, using high gain antennas at Mission Control, until potential loss of signal, due to loss of

line-of-sight at very low altitude;

Mission control will record the last known GPS coordinates at mission control for reference;

All EuRoC LCD handheld receivers will stay powered while recovery operations are running;

Teams shall each have at least one tracking receiver. Several can be advantageous for more

efficient tracking and recovery;

Recovery teams will change LCD handheld receiver operating frequencies in the field, as

necessary to recover all jettisoned stages and/or deployable payloads;

Teams may leave their TRS Flight Computer powered during recovery and transportation back

to Mission Control, provided that any recovery systems are brought back into a safe state,

where actuation of recovery systems (regardless of status) is prevented;

A representative of the EuRoC organisation will inspect the recovered flight vehicles at Mission

Control and extract flight data and apogee from the TRS Flight Computer, as possible.

•

C.3.1.5. O

THER ALTITUDE LOGGING AND

GPS

TRACKING SYSTEMS

Teams are welcome to operate and fly one or more of their own altitude logging and/or GPS tracking

solutions, in addition to the mandatory systems, described in this addendum.

Such systems may have superior performance or range compared to the selected mandatory Eggtimer

systems, but this does not exempt teams from implementing the mandatory systems.

European Rocketry Challenge

–

Design, Test & Evaluation Guide

Page 49 of 88

L 77 - 2022-23 (2. samling) - Bilag 1: Høringssvar og høringsnotat, fra uddannelses- og forskningsministeren

Portugal Space Reference PTS_EDU_EuRoC_ST_000455

Version 03, Date 04.02.2021

Again, the EuRoC organisation is firm on testing and validating a system and procedures for the fair,

equal and transparent recording of apogees, and the implementation of efficient tracking and

recovery operations.

C.3.2. E

TESTING OF THE

GGTIMER

TRS F

LIGHT

OMPUTER

The EuRoC organisation conducted both GPS tracking field tests as well as simulated flight tests, using

a vacuum chamber. A short summary of the tests used to evaluate and approve the Eggtimer TRS Flight

Computer (and other Eggfinder products) is outlined as follows.

Note:

The testing was performed using the EU license free frequency version of the Eggtimer product

line (869 MHz range), hence the expected range of the 433 MHz range Ham-version products is

expected to be roughly double of what is described below.

The entire Eggfinder range of GPS tracking solutions, as well as the TRS Flight Computer, utilizes the

same half-duplex RF module for telemetry. As expected, range performance has been found to be

similar for all products.

C.3.2.1. O

GROUND

GPS

TRACKING TESTS

Two cases of worst-case scenario testing were carried out:

•

An Eggfinder TX was placed in a wet crop field, 10 cm off the ground (line of sight), with the

aim of having the wet vegetation attenuating the RF link as much as possible;

An Eggfinder TX was placed at a tree stub in a rugged and heavily forested area.

European Rocketry Challenge

–

Design, Test & Evaluation Guide

Page 50 of 88

L 77 - 2022-23 (2. samling) - Bilag 1: Høringssvar og høringsnotat, fra uddannelses- og forskningsministeren

Portugal Space Reference PTS_EDU_EuRoC_ST_000455

Version 03, Date 04.02.2021

Figure 8: Eggfinder TX placed in wet crop field at a distance of 530 meters (heavy digital zoom; red arrow marks TX

location).

(Source: Jacob Larsen)

Figure 9: Another worst-case scenario: A rugged and heavily forested test area. (Source: Jacob Larsen)

European Rocketry Challenge

–

Design, Test & Evaluation Guide

Page 51 of 88

L 77 - 2022-23 (2. samling) - Bilag 1: Høringssvar og høringsnotat, fra uddannelses- og forskningsministeren

Portugal Space Reference PTS_EDU_EuRoC_ST_000455

Version 03, Date 04.02.2021

While the crop field test illustrated in Figure 8 did feature line-of-sight between TX transmitter and

LCD handheld receiver, ground effects and wet vegetation should provide a challenging test setup.

Test results indicated that the RF-link range was about 500 meters with a wire antenna on the TX and

an Eggtimer supplied 3 dB stub antenna, as illustrated in Figure 10.

The forest test range limitation was primarily governed by loss of line-of-sight, due to bumpy terrain,

while wet tree trunks were also identified as efficient signal attenuators.

Circling the transmitter in the forest revealed a consistent RF-link range of about 300 meters,

regardless of terrain and foliage.

It can thus be concluded, that at the absolute worst-case scenario of an 869 MHz EU licence free

version in a forest, an LCD handheld receiver will pick up the RF-link signal at a minimum distance of

300 meters, regardless of conditions.

If getting within 300 meters of a GPS transmitter, the LCD handheld receiver will pick up the tracking

signal, no matter what terrain it is in.

433 MHz “Ham” versions are expected to exhibit about twice the range of the above.

Figure 10: LCD handheld receiver detects GPS transmitter at a distance of 530 meters.

(custom enclosure, 3dB stub antenna, SMA board connector options) (Source: Jacob Larsen)

European Rocketry Challenge

–

Design, Test & Evaluation Guide

Page 52 of 88

L 77 - 2022-23 (2. samling) - Bilag 1: Høringssvar og høringsnotat, fra uddannelses- og forskningsministeren

Portugal Space Reference PTS_EDU_EuRoC_ST_000455

Version 03, Date 04.02.2021

C.3.2.2. A

GROUND

GPS

TRACKING TESTS

No air-to-ground GPS tracking tests have been conducted as of time of writing. The manufacturer

indicates about 15 km of line-of-sight aerial range with the Ham-version and a stub antenna. About

half that with the EU license free 869 MHz version.

Based on the above, lack of range of the Eggfinder equipment is not currently a concern.

C.3.2.3. TRS F

LIGHT

OMPUTER SIMULATED FLIGHT TEST

In the interest of testing and validating the performance of the TRS Flight Computer, a simulated flight

test case was devised, using a vacuum chamber to simulate the ambient pressure drop experienced

during ascent.

The test objectives were as follows:

•

To simulate a trajectory the TRS Flight Computer would interpret as a real launch;

To record flight and altitude data onboard the TRS non-volatile memory;

To rehearse and gain experience with the TRS Flight Computer arming sequence;

To rehearse the interpretation of downlink telemetry and flight events displayed at the LCD

handheld receiver;

To rehearse downloading and visualizing the flight data stored in the TRS Flight Computer non-

volatile memory.

The test consisted of quickly drawing a vacuum to simulate ascent and then gradually opening a

manual bleed valve to simulate apogee and descent.

The flight data is easily downloaded from the TRS Flight Computer, using a laptop and the USB/TTL

UART data cable. The data is downloaded and saved into a log file as comma separated ascii values,

using a terminal program.

Figure 11 illustrates the flight data imported into an excel spreadsheet and displayed in a suitable

graph format.

There are two things to note in Figure 11:

•

All altitudes and velocity data from the TRS Flight Computer are displayed and logged in units

of feet and feet/sec. The TRS Flight Computer is not capable of transmitting and/or recording

flight data in metric units.

This is in stark contrast to the GPS and tracking data downrange displayed on the LCD

handheld receiver, which can be switched between feet and meters.

European Rocketry Challenge

–

Design, Test & Evaluation Guide

Page 53 of 88

L 77 - 2022-23 (2. samling) - Bilag 1: Høringssvar og høringsnotat, fra uddannelses- og forskningsministeren

Portugal Space Reference PTS_EDU_EuRoC_ST_000455

Version 03, Date 04.02.2021

•

The drogue deployment is delayed, contrary to supposed to happen at “nose-over”, due to an

artifact of the test setup. The apogee is a discontinuous kink in the pressure profile, in contrast

to the continuous inverted parabola expected. The flight computer waits for one second of

vertical velocity below 100 ft/sec, before it arms and fires the drogue pyro channel. This is why

the drogue deployment event does not happen at nose-over in the below test.

The TRS Flight Computer deployment channels work as advertised. It is the test setup

which is not capable of generating a smooth simulated apogee.

TRS Flight Computer simulated flight test using vacuum

chamber: Test 4

14400, 11410

12000

10000

8000

21950, 10656

1500

1000

500

6000

4000

2000

60950, 1496

-500

-1000

-1500

120000

20000

40000

60000

80000

100000

Time [ms]

Filtered_Alt

Drogue deploy

Apogee

Main deploy

Nose-over

Filtered:Veloc

Figure 11: TRS downloaded flight data visualization from vacuum chamber test #4, 1500 feet main deployment set

(delayed drogue deployment event is an artifact of having too sharp a kink at apogee). (Source: Jacob Larsen)

C.4. M

ANDATORY SYSTEM

EYPOINTS

RECOMMENDATIONS AND REQUIREMENTS SUMMARY

C.4.1. M

ANDATORY ALTITUDE LOGGING AND GPS TRACKING SYSTEM

For single-stage flight vehicles (and upper-most stage vehicles), the mandatory Official Altitude

Logging and Tracking device to be installed is the Eggtimer TRS Flight Computer.

•

The TRS (Total Recovery System) device combines:

A COTS dual-channel deployment computer;

European Rocketry Challenge

–

Design, Test & Evaluation Guide

Page 54 of 88

L 77 - 2022-23 (2. samling) - Bilag 1: Høringssvar og høringsnotat, fra uddannelses- og forskningsministeren

Portugal Space Reference PTS_EDU_EuRoC_ST_000455

Version 03, Date 04.02.2021

Barometric pressure sensor for apogee determination and recovery systems

deployment;

A non-volatile memory for recording flight data over the full flight duration;

GPS

tracking and recovery transmitter.

C.4.2. TRS F

LIGHT

OMPUTER

REQUENCY

ANGE

EuRoC will make specific frequencies available for tracking system use, without the need for specific

radio amateur licenses. Eggtimer Ham-frequency equipment can thus legally be used during EuRoC

without a license. This means that all mandatory TRS Flight Computers MUST be purchased in the US

“Ham” frequency range.

•

The recommended package to buy is (approximately $200):

The “Eggtimer TRS/LCD Starter set, 70cm Ham versions” (includes data cable +

terminal blocks + external antennas) at $168 (2021 price).

The “Eggfinder LCD-GPS module kit” at $40 (2021 price).

C.4.3. “EU”

TRS F

LIGHT

OMPUTER VERSIONS

While the “EU” license free version of the TRS sounds like a compelling option, there is a major

drawback in the fact, that the EU license free band contains only three separate channels/frequencies

(and TRS systems cannot share the same frequency).

This is a major problem since multiple flight vehicles will be sitting on the launch rails at the opening

of a launch window. These vehicles will (when engine technology permits) be launched successively,

as soon as the previous flight vehicle is believed landed, with no time for additional pre-flight

preparations in between launches.

•

Therefore purchasing the “EU” version of the TRS

Flight Computer is highly discouraged,

despite being legal to use;

However, for teams or flight vehicles already having an “EU”-frequency

versions of Eggtimer

products, these “EU” frequency systems can be flown at EuRoC as a replacement for the

“HAM” frequency version. The EuRoC organization only has one “EU” compatible receiver,

limiting its use.

European Rocketry Challenge

–

Design, Test & Evaluation Guide

Page 55 of 88

L 77 - 2022-23 (2. samling) - Bilag 1: Høringssvar og høringsnotat, fra uddannelses- og forskningsministeren

Portugal Space Reference PTS_EDU_EuRoC_ST_000455

Version 03, Date 04.02.2021

C.4.4. P

ROCUREMENT OF

TRS

COMPATIBLE RECEIVER

(

)

While teams are not required to procure one or more receivers for the Eggfinder “Ham-version” TRS

Flight Computer, according to the EuRoC Rules and Requirements, teams are strongly encouraged to

procure the above “full kit package”.

•

The TRS Flight Computer is best programmed wirelessly from the LCD receiver while firmware

updating, and flight data download happens via the USB-serial adaptor data cable (included

in package).

The LCD receiver has several test functions (including deployment channel testing) which are

very useful.

Having an LCD receiver allows teams to train both programming of the TRS Flight Computer

as well as GPS tracking.

It is difficult to underscore how much easier the GPS tracking and location becomes with the

LCD-GPS

module kit addition to the LCD receiver. Don’t forget to order it.

It is not encouraged to add the Bluetooth option, as the LCD-GPS programming port is much

more useful in the wired configuration. An openlogger module can alternatively be installed

to capture and store all received telemetry. This is very useful for post-flight analysis,

especially of the vehicle is lost.

•

C.4.5. M

ANDATORY

GPS

TRACKING SYSTEMS FOR DEPLOYABLE PAYLOADS OR STAGES

While the upper-most stage of any multi-stage flight vehicle, as well as any single-stage flight vehicle,

must feature the mandatory Eggfinder TRS Flight Computer for official altitude recording and GPS

tracking, this is not the case for deployable payloads or stages.

It is still mandatory to implement a Eggfinder GPS tracking device for lower stages and deployable

payloads, as the EuRoC operated LCD handheld receivers (or student operated LCD receivers) can be

reprogrammed in the field to track each flight vehicle component.

While the Eggtimer TRS Flight Computer can be utilized in all stages and deployable payloads, there

are some simpler, smaller and cheaper compatible alternatives for lower stages and deployable

payloads:

•

The Eggfinder TX and TX-mini GPS tracking transmitters are fully eligible for tracking and

location any lower stages or deployable payloads.

The Eggfinder TX and TX-mini transmitters enable EuRoC recovery teams to track and locate

lower stages and deployable payloads, using already available LCD handheld receivers, while

the flight data and apogee of such stages and payloads are not relevant to team scoring.

European Rocketry Challenge

–

Design, Test & Evaluation Guide

Page 56 of 88

L 77 - 2022-23 (2. samling) - Bilag 1: Høringssvar og høringsnotat, fra uddannelses- og forskningsministeren

Portugal Space Reference PTS_EDU_EuRoC_ST_000455

Version 03, Date 04.02.2021

•

The Eggfinder LCD receivers are fully compatible with the TX and TX-mini and can be used to

easily program the RF frequency of these transmitters.

C.4.6. U

TIME REQUIREMENTS OF TRANSMITTERS

The following requirements pertain to the mandatory Eggtimer TRS Flight Computer, TX, TX-mini and

LCD receivers:

•

The battery capacity of the various Eggtimer/finder transmitters must be sufficient to keep the

GPS tracking systems running continually for at least 12 hours.

C.4.7. U

PDATING FIRMWARE TO THE CUSTOM

Z CHANNEL STEP VERSION

Due to the differences of EU and the US, the frequencies allotted by the Portuguese authorities,

channel

centre frequencies may lie at frequencies “odd” to the US Ham system. Consequently,

students will have to update the firmware of the TRS Flight Computer (and any LCD-GPS receivers)

with a special firmware version capable of 25 kHz channel selection.

The TRS firmware update is described in the “How to update the Eggtimer TRS firmware” document

at the Eggtimer support web page.

Direct link:

http://eggtimerrocketry.com/wp-content/uploads/2018/06/Eggtimer_TRS_Flash_

Update_Instructions1.pdf

Likewise,

there

document

for

updating

the

LCD-GPS

firmware:

http://eggtimerrocketry.com/wpcontent/uploads/2020/04/Eggfinder-LCD-Flash-Update-

Instructions-1.pdf

Both firmware updates were performed as a part of testing the system, since both devices were

delivered with outdated firmware. The flashing procedure uses the USB data cable and should not

present a challenge to student teams.

C.4.8. TRS F

LIGHT

OMPUTER SAMPLE FILE

A sample file captured from a TRS Flight Computer illustrates the recorded data (GPS location and

some NMEA sentences deleted or redacted for clarity). Worthwhile noting, besides the standard

NMEA sentences:

•

{DM}

is deployment status

D for

undeployed drogue chute

European Rocketry Challenge

–

Design, Test & Evaluation Guide

Page 57 of 88

L 77 - 2022-23 (2. samling) - Bilag 1: Høringssvar og høringsnotat, fra uddannelses- og forskningsministeren

Portugal Space Reference PTS_EDU_EuRoC_ST_000455

Version 03, Date 04.02.2021

d for deployed drogue chute

M for undeployed main chute

m for deployed main chute

•

<2>,<-6>

(or other varying number) is the barometric altitude in feet at any time.

<1015>, <1015>

(repeated) is the achieved apogee

This achieved apogee term is however not broadcasted before the TLS Flight Computer has

determined that the rocket has landed. A landing event is determined as an altitude of less

than 30 feet above ground level for 5 seconds, or alternately when the TRS runs out of flight

memory.

@JSL EggTimer@

$GPGGA,211127.000,XXXX.7710,N,0XXXX.4560,E,1,05,3.7,23.1,M,41.8,M,,0000*6C

$GPGSA,A,3,13,15,05,23,18,,,,,,,,4.8,3.7,3.1*33

$GPRMC,211127.000,A,XXXX.7710,N,0XXXX.4560,E,0.42,222.64,140821,,,A*6A

{DM}

<2>

@JSL EggTimer@

$GPGGA,211128.000,XXXX.7709,N,0XXXX.4569,E,1,05,3.7,23.1,M,41.8,M,,0000*62

$GPGSA,A,3,13,15,05,23,18,,,,,,,,4.8,3.7,3.1*33

$GPRMC,211128.000,A,XXXX.7709,N,0XXXX.4569,E,0.30,222.64,140821,,,A*61

{dm}

<-6>

@JSL EggTimer@

$GPGGA,211131.000,XXXX.7709,N,0XXXX.4571,E,1,05,3.7,23.0,M,41.8,M,,0000*62

$GPGSA,A,3,13,15,05,23,18,,,,,,,,4.8,3.7,3.1*33

$GPRMC,211131.000,A,XXXX.7709,N,0XXXX.4571,E,0.00,222.64,140821,,,A*63

{dm}

<1015>

@JSL EggTimer@

$GPGGA,211134.000,XXXX.7709,N,0XXXX.4571,E,1,05,3.7,23.0,M,41.8,M,,0000*67

$GPGSA,A,3,13,15,05,23,18,,,,,,,,4.8,3.7,3.1*33

$GPRMC,211134.000,A,XXXX.7709,N,0XXXX.4571,E,0.00,222.64,140821,,,A*66

{dm}

European Rocketry Challenge

–

Design, Test & Evaluation Guide

Page 58 of 88

L 77 - 2022-23 (2. samling) - Bilag 1: Høringssvar og høringsnotat, fra uddannelses- og forskningsministeren

Portugal Space Reference PTS_EDU_EuRoC_ST_000455

Version 03, Date 04.02.2021

<1015>

C.4.9. LCD

HANDHELD RECEIVER

Figure 12: LCD handheld receiver with backlight and custom 3D printed enclosure. (Source: Jacob Larsen)

The LCD handheld receiver is well described in this document, thus this section focuses only on

observations and specific characteristics of the device.

•

It is necessary to wipe the EEPROM flight memory before use, according to the LCD receiver

user guide.

As illustrated in Figure 12, the backlight option in the LCD handheld receiver is very useful

after dark, if it is not excessively bright. An 86 Ohm series resistor had to be fitted on the leads

going to the backlight, which also brings the back light current consumption down to about 20

mA.

Without this series resistor, the backlight acts like a blinding flood light, gulping up about 200

mA in the process.

•

The programming port on the rear face of the LCD handheld receiver PCB can be used to log

downlink telemetry data from the TRS Flight Computer, using a USB/TTL UART data cable,

although less elegant than the RX receiver solution outlined in section C.7.. Another

recommended solution is to install an openlog breakout board for telemetry capture.

European Rocketry Challenge

–

Design, Test & Evaluation Guide

Page 59 of 88

L 77 - 2022-23 (2. samling) - Bilag 1: Høringssvar og høringsnotat, fra uddannelses- og forskningsministeren

Portugal Space Reference PTS_EDU_EuRoC_ST_000455

Version 03, Date 04.02.2021

Figure 13: A USB/TTL UART data cable can be used to record TRS Flight Computer downlink data to a laptop.

(Source: Jacob Larsen)

C.5. E

GGTIMER

TRS

ALTITUDE LOGGING AND

GPS

TRACKING SYSTEM

ESSONS

EARNED

Based on previous editions of EuRoC a number of findings, advantages, disadvantages, and risks for

the mandatory (Eggtimer TRS based) altitude logging and GPS tracking system have been compiled

below (in no particular order):

•

When properly implemented, the GPS tracing performance is excellent. A rocket which

unintentionally deployed its main chute at an altitude of 9593 meters was continuously

tracked until horizon dependent loss of line-of-sight, at a downrange of 27 kilometers, using a

cheap type 5-element Yagi antenna.

The biggest drawback of the Eggtimer system is that the quality control is left up to the

students assembling and testing the correct performance and tracking range of the system.

This responsibility of inspecting own work and validating performance cannot be overstated.

In some of the worst cases seen, GPS tracking telemetry was lost a little over 100 meters past

the Mission Control tent, which corresponds to the RF-module output not being electrically

connected to the transmitter antenna trace (or very bad installation and RF practices). Such

serious issues will be discovered with rudimentary range testing and performance assessment;

•

European Rocketry Challenge

–

Design, Test & Evaluation Guide

Page 60 of 88

L 77 - 2022-23 (2. samling) - Bilag 1: Høringssvar og høringsnotat, fra uddannelses- og forskningsministeren

Portugal Space Reference PTS_EDU_EuRoC_ST_000455

Version 03, Date 04.02.2021

•

The Eggtimer TRS documentation quality is lacking. The EuRoC organization will require a

significant improvement of the documentation from the manufacturer, or as a minimum

interact with the manufacturer until all functionality is understood, such that it can be clearly

communicated to teams;

The Eggtimer TRS system requires training and accumulation of experience to realize its full

potential, which is considerable, once full system understanding is achieved. It is a cheap field-

programmable, 2-channel deployment computer, with position and altitude downlink,

deployment test features, e-match continuity checking, stand-alone GPS tracking receiver and

flight data recorder;

Print a rugged case for the LCD tracking receiver and let that one have the experience of

constant exposure to fine flying dust and rattling around in the bottom of an army truck going

off-road in the attempts of recovering a stray rocket, instead of your mint condition Macbook.

Link

free

printable

LCD

tracking

receiver

enclosure:

https://www.dropbox.com/sh/i1p1tfhbfjeivvw/AAD5kwoKUdgcNXBqD6kyJ7W4a?dl=0

Appoint a dedicated GPS tracking and recovery responsible team member along with 3-4

recovery team members. Field-train and drill the recovery team in quickly and efficiently

tracking down the rocket, by having team members (not part of the recovery team) place the

rocket in unknown locations and have the recovery team do a series of increasingly

challenging tracking challenges;

Re-acquiring a GPS tracking signal given only an approximate heading and a 3-5 kilometer

downrange is quite challenging. Finding a rocket in thick vegetation without a functional GPS

tracking signal and a handheld tracking receiver is close to impossible. Both scenarios have

proved to be surprisingly common at EuRoC;

It is highly recommended to integrate an openlogger breakout board in the back of the

Eggtimer LCD receiver. This means that the human readable ASCII telemetry downlink data

stream can be captured for post-flight analysis, even in the event of an in-flight failure leading

to a total loss of the vehicle. Besides GPS NMEA sentences, the TRS data downlink barometric

altitude and recovery system deployment events.

A cheap and widely available directional 5-element Yagi antenna with UHF-SMA adaptor cable

does wonders for the tracking range.

•

European Rocketry Challenge

–

Design, Test & Evaluation Guide

Page 61 of 88

L 77 - 2022-23 (2. samling) - Bilag 1: Høringssvar og høringsnotat, fra uddannelses- og forskningsministeren

Portugal Space Reference PTS_EDU_EuRoC_ST_000455

Version 03, Date 04.02.2021

Figure 14: Yagi 5-element high gain antenna.

C.6. C

USTOM

PRINTED

LCD

RECEIVER ENCLOSURE

A convenient custom enclosure was developed and refined as a part of the Eggtimer/Eggfinder test

campaign, in order to ruggedize the LCD handheld receiver for field use.

The manufacturer’s plastic enclosure and installation of the LCD

receiver in an odd-sized rectangular

box called for something more refined.

The stl-files are for free printing and use, as well as a step-file model of the enclosure design being

available for reference. The latest version files can also be retrieved from the following Dropbox link,

until further notice:

https://www.dropbox.com/sh/i1p1tfhbfjeivvw/AAD5kwoKUdgcNXBqD6kyJ7W4a?dl=0.

European Rocketry Challenge

–

Design, Test & Evaluation Guide

Page 62 of 88

L 77 - 2022-23 (2. samling) - Bilag 1: Høringssvar og høringsnotat, fra uddannelses- og forskningsministeren

Portugal Space Reference PTS_EDU_EuRoC_ST_000455

Version 03, Date 04.02.2021

Figure 15: Updated ruggedized custom enclosure for the LCD handheld receiver. (Source: Jacob Larsen)

Relevant details, in no particular order:

•

This enclosure design is free for printing and use;

The “CS” is a reference to Copenhagen Suborbitals (www.copsub.com);

The red pushbutton is included in the Eggfinder LCD handheld receiver kit;

A double pole, double throw switch, switches power and backlight on and off simultaneously;

The design consists of three parts:

Front section;

Rear section;

Battery cap (snaps into place).

•

The rear section contains an opening, providing access to the programming port, which is used

to program TX, Mini or RX operating frequencies;

Put a piece of tape over the opening when not in use. It keeps the dirt out of the unit.

European Rocketry Challenge

–

Design, Test & Evaluation Guide

Page 63 of 88

L 77 - 2022-23 (2. samling) - Bilag 1: Høringssvar og høringsnotat, fra uddannelses- og forskningsministeren

Portugal Space Reference PTS_EDU_EuRoC_ST_000455

Version 03, Date 04.02.2021

Figure 1: Blue recess and dark grey notch mating scheme. (Source: Jacob Larsen)

•

The front and rear enclosure mates accurately using a notch-and-recess fit. Put a few drops of

glue in there, if you want to assemble the enclosure permanently;

The GPS-LCD module add-on is conveniently soldered to the LCD receiver PCB using a 3-pin

header.

Figure 18: Crude CAD model of LCD receiver PCBs, with LCD-GPS module add-on soldered in place.

(Source: Jacob Larsen and Eggtimer)

•

Eight PCB mounting points are integrated into the front and rear enclosures. Tap M3 threading

in all eight and fit each of the two LCD receiver PCBs in their respective enclosure segments,

using countersunk M3x6mm countersunk screws with reduced head.

European Rocketry Challenge

–

Design, Test & Evaluation Guide

Page 64 of 88

L 77 - 2022-23 (2. samling) - Bilag 1: Høringssvar og høringsnotat, fra uddannelses- og forskningsministeren

Portugal Space Reference PTS_EDU_EuRoC_ST_000455

Version 03, Date 04.02.2021

Figure 19: Rear section illustrating the programming port opening and where to tap M3 threading. (Source: Jacob Larsen)

•

The battery compartment fits a 2S 1900 mAh LiPo battery with measures 115 x 34 x 18 mm,

which should provide about 18 hours of operation per charge. The printed battery

compartment cap clicks nicely into position.

Do not print this enclosure using carbon fibre reinforced plastics, since the conductivity of the carbon

fibre may negatively impact the internal GPS receiver sensitivity.

C.7. N

OTES ON ADDITIONAL TESTED

GGFINDER DEVICES

This section lists some findings on tested Eggfinder equipments, other than the TRS Flight Computer.

C.7.1. E

GGFINDER

TX T

RANSMITTER

Figure 20: Eggfinder TX transmitter. (Source: Eggtimer)

European Rocketry Challenge

–

Design, Test & Evaluation Guide

Page 65 of 88

L 77 - 2022-23 (2. samling) - Bilag 1: Høringssvar og høringsnotat, fra uddannelses- og forskningsministeren

Portugal Space Reference PTS_EDU_EuRoC_ST_000455

Version 03, Date 04.02.2021

The Eggfinder TX transmitter is a simple and useful GPS tracking transmitter. Some observations made

during assembly and testing:

•

The device is quite simple and just transmits the onboard GPS NMEA sentences at 9600 baud,

to any receiver listening.

It has the added advantage that it features PCB space for an Openlogger device, if one wants

to log whatever is transmitted onboard. (Eggtimer stock Openloggers)

The TX transmitter will accommodate a SMA PCB edge-connector, required for external

antennas, contrary to the Mini transmitter. (Eggtimer stocks SMA PCB edge connectors).

The RF module of the tested device would not transmit anything, until the RF module

frequency was reprogrammed, using the LCD handheld receiver and the included 3-wire

programming cable. It worked flawlessly since then.

The TX transmitter has an included jumper for setting it into programming mode. This is

contrary to the Mini transmitter, which utilizes inconvenient solder jumpers.

•

C.7.2. E

GGFINDER

TX-

MINI TRANSMITTER

Figure 21: Eggfinder Mini transmitter. (Source: Eggtimer)

The Eggfinder Mini transmitter is a smaller version of the TX transmitter, intended for very small

rockets. Some observations made during assembly and testing:

•

The Mini transmitter uses solder jumpers for putting the device either in programming or

running mode. This is inconvenient in the event of having to change the RF-link frequency in

the field.

This device cannot accommodate an SMA PCB edge connector. It is stuck with the little stub

antenna.

Some issues were encountered as difficulties with getting good solder joints between the PCB

and the GPS module.

European Rocketry Challenge

–

Design, Test & Evaluation Guide

Page 66 of 88

•

L 77 - 2022-23 (2. samling) - Bilag 1: Høringssvar og høringsnotat, fra uddannelses- og forskningsministeren

Portugal Space Reference PTS_EDU_EuRoC_ST_000455

Version 03, Date 04.02.2021

•

The Mini transmitter, with its short stub antenna, had a very similar RF-link range, compared

to the TX transmitter with a wire antenna.

C.7.3. E

GGFINDER

“

DONGLE

”

RECEIVER

Figure 22: Eggfinder RX "dongle" receiver. (Source: Eggtimer)

The RX receiver is potentially a useful device, considering how inexpensive it is. Some observations

made during assembly and testing:

•

The RX receiver is very inexpensive due to the lack of a GPS receiver.

The RX receiver is available in both a Bluetooth and a USB cable option, of which the latter

seems more useful.

The RX receiver frequency is easily programmed with an LCD handheld receiver and the

included 3-wire programming cable.

The “USB version” of the RX receiver can be powered directly from a laptop, if using a USB/TTL

UART data cable (included). No other accessories required.

The RX receiver (USB cable version) and a laptop makes for an excellent TRS Flight Computer

standalone telemetry backup data logger. While the TRS Flight Computer logs high-speed flight data

to onboard non-volatile EEPROM, said EEPROM may in some unfortunate incidents disintegrate upon

“landing”, taking the recorded flight data with it into oblivion.

If an RX receiver has logged the telemetry, which also includes the altitude reading from the TRS Flight

Computer barometric pressure sensor, the trajectory and apogee may be reconstructed from these

data, enabling the EuRoC Jury to award points for achieved apogee.

European Rocketry Challenge

–

Design, Test & Evaluation Guide

Page 67 of 88

L 77 - 2022-23 (2. samling) - Bilag 1: Høringssvar og høringsnotat, fra uddannelses- og forskningsministeren

Portugal Space Reference PTS_EDU_EuRoC_ST_000455

Version 03, Date 04.02.2021

APPENDIX D: FLIGHT READINESS REVIEW CHECKLIST

Table 3: Flight Readiness Review checklist.

ECTION

ESCRIPTION

PROPULSION SYSTEMS

Upon request, the flier should provide the inspector

with hardcopy checklist procedures for the

propulsion system's safe handling, assembly,

disassembly, and operation (both nominal and

offnominal/contingency

flows)

–

including

selfinspection/verification steps which make

individual team members accountable to one

another for having completed the preceding

process(es).

CTIONS TO BE TAKEN

Checklist

Simple confirmation

Inspection on site

Launch vehicles entering EuRoC shall use non-toxic

propellants. Ammonium perchlorate composite

propellant (APCP), potassium nitrate and sugar (also

known as "rocket candy"), nitrous oxide, liquid

oxygen (LOX), hydrogen peroxide, kerosene,

propane, alcohol, and similar substances, are all

Non-toxic Propellants

considered non-toxic. Toxic propellants are defined

as those requiring breathing apparatus, unique

storage and transport infrastructure, extensive

personal protective equipment (PPE), etc.

Homemade propellant mixtures containing any

fraction of toxic propellants are also prohibited.

The sum of all rocket stages' impulse must either

not exceed 40,960 newton-seconds, or the Flier

must have previously consulted with EuRoC on

provisions for launching a larger rocket.

The design must provide for positive retention of

the propulsion system within the airframe - leaving

no possibility for the propulsion system to shift from

its retaining device(s) and jettison itself.

A "structural chain" that transfers the propulsion

system thrust to various points on the rocket

structure must exist and it must be capable of

withstand these loads.

Simple confirmation

Total Impulse

Simple confirmation

Motor Retention

Inspection on site

Proof by reasoned

argumentation

Inspection on site

Proof by reasoned

argumentation

Thrust Structure

European Rocketry Challenge

–

Design, Test & Evaluation Guide

Page 68 of 88

L 77 - 2022-23 (2. samling) - Bilag 1: Høringssvar og høringsnotat, fra uddannelses- og forskningsministeren

Portugal Space Reference PTS_EDU_EuRoC_ST_000455

Version 03, Date 04.02.2021

Thrust Curve

Upon request, the flier must provide the inspector

with hardcopy thrust curve data for each individual

rocket motor or engine implemented.

Proof by calculation

ROPULSION

YSTEM

AFING AND

RMING

Upon request, the flier should provide the inspector

with hardcopy checklist procedures for any of the

propulsion system's unique final on-pad

preparations, pre-flight, and launch (both nominal

and off-nominal/abort/mishap flows) - including

self-inspection/verification steps which make

individual team members accountable to one

another for having completed the preceding

process(es).

Pre-flight and

Countdown

Procedure

Simple confirmation

Inspection on site

All ground-started propulsion system ignition

circuits/sequences shall not be "armed" until all

personnel are at least 15 m away from the launch

vehicle. The provided launch control system

satisfies this requirement by implementing a

removable "safety jumper" in series with the pad

Ground-start Ignition

relay box's power supply. The removal of this single

Circuit Arming

jumper prevents firing current from being sent to

any of the launch rails associated with that pad relay

box. Furthermore, access to the socket allowing

insertion of the jumper is controlled via multiple

physical locks to ensure that all parties have positive

control of their own safety.

All upper stage (i.e., air-start) propulsion systems

shall be armed by launch detection (e.g.,

accelerometers, zero separation force [ZSF]

Air-start

Ignition

electrical shunt connections, break-wires, or other

Circuit Arming

similar methods). Regardless of implementation,

this arming function will prevent the upper stage

from arming in the event of a misfire.

Hybrid and liquid propulsion systems shall

Propellant Offloading implement a means for remotely controlled venting

or offloading of all liquid and gaseous propellants in

After Launch Abort

the event of a launch abort.

Simple check

Proof by reasoned

argumentation

Inspection on site

Proof by reasoned

argumentation

European Rocketry Challenge

–

Design, Test & Evaluation Guide

Page 69 of 88

L 77 - 2022-23 (2. samling) - Bilag 1: Høringssvar og høringsnotat, fra uddannelses- og forskningsministeren

Portugal Space Reference PTS_EDU_EuRoC_ST_000455

Version 03, Date 04.02.2021

All upper stage ignition systems shall comply with

same requirements and goals for "redundant

Air-start

Ignition electronics" and "safety critical wiring" as recovery

systems

—

understanding that in this case

Circuit Electronics

"initiation" refers to upper stage ignition rather

than a recovery event.

Staging Ignition

Commit Criteria

Positive State

Indication

The electronics controlling the various staging

events must inhibit staging if the rockets' flight

profile deviates from predicted nominal behaviour.

Each independent set of electronics controlling

staging events must provide sensory (i.e., visual or

auditory) indication of its activation.

Simple confirmation

Inspection on site

Proof by reasoned

argumentation

Simple confirmation

Inspection on site

The electronics controlling stage ignition in design's

implementing "drag-separation" must not be

Special Consideration

located in the separating stage - where premature

for "Drag Separation"

separation could prevent ignition of the following

stage.

SRAD P

ROPULSION

YSTEM

ESTING

SRAD and modified COTS propulsion system

combustion chambers shall be designed and tested

according to the SRAD pressure vessel requirements

defined in Section 4.2. Note that combustion

chambers are exempted from the requirement for a

relief device.

SRAD and modified COTS propulsion systems using

liquid propellant(s) shall successfully (without

significant anomalies) have completed a propellant

loading and off-loading test in "launch-

configuration", prior to the rocket being brought to

the competition. This test may be conducted using

either actual propellant(s) or suitable proxy fluids,

with the test results to be considered a mandatory

deliverable and an annex to the Technical Report, in

the form of a loading and off-loading checklist,

complete with dates, signatures (at least three) and

a statement of a successful test. Failure to deliver

this annex will automatically result in a “denied”

flight status. Loading and unloading of liquid

propellants must be a well-drilled, safe and efficient

operation at the competition launch rails.

European Rocketry Challenge

–

Design, Test & Evaluation Guide

Simple confirmation

Inspection on site

Combustion

Chamber Pressure

testing

Proof by previous

testing

Hybrid and Liquid

Propulsion System

Tanking Testing

Proof by previous

testing

Page 70 of 88

L 77 - 2022-23 (2. samling) - Bilag 1: Høringssvar og høringsnotat, fra uddannelses- og forskningsministeren

Portugal Space Reference PTS_EDU_EuRoC_ST_000455

Version 03, Date 04.02.2021

SRAD propulsion systems shall successfully (without

significant anomalies) complete an instrumented

(chamber pressure and/or thrust), full scale

(including system working time) static hot-fire test

prior to EuRoC. In the case of solid rocket motors,

this test needs not to be performed with the same

motor casing and/or nozzle components intended

for use at the EuRoC (i.e., teams must verify their

Static Hot-fire testing casing design, but are not forced to design

reloadable/reusable motor cases). The test results

and a statement of a successful test, complete with

dates and signatures (at least three) are considered

a mandatory deliverable and an annex to the

Technical Report. Failure to deliver this annex will

automatically result in a “denied” flight status. See

Section 2.6.6. for more information.

Proof by previous

testing

RECOVERY SYSTEMS AND AVIONICS

Upon request, the flier must provide the inspector

with hardcopy checklist procedures for the recovery

system's safe handling, assembly, disassembly, and

operation

(both

nominal

and

offnominal/contingency

flows)

including

selfinspection/verification steps which make

individual team members accountable to one

another for having completed the preceding

process(es).

Upon request, the flier must provide the inspector

with hardcopy checklist procedures for any of the

recovery system's unique final on-pad preparations,

pre-flight, and launch (both nominal and

offnominal/abort/mishap flows) - including

selfinspection/verification steps which make

individual team members accountable to one

another for having completed the preceding

process(es).

Checklist

Simple confirmation

Inspection on site

Pre-flight and

Countdown

Procedure

Simple confirmation

Inspection on site

European Rocketry Challenge

–

Design, Test & Evaluation Guide

Page 71 of 88

L 77 - 2022-23 (2. samling) - Bilag 1: Høringssvar og høringsnotat, fra uddannelses- og forskningsministeren

Portugal Space Reference PTS_EDU_EuRoC_ST_000455

Version 03, Date 04.02.2021

Dual-event

Parachute and

Parafoil Recovery

Each independently recovered launch vehicle body,

anticipated to reach an apogee above 450 m above

ground level (AGL), shall follow a "dual-event"

recovery operations concept, including an initial

deployment event (e.g., a drogue parachute

deployment; reefed main parachute deployment or

similar) and a main deployment event (e.g., a main

parachute deployment; main parachute un-reefing

or similar). Independently recovered bodies, whose

apogee is not anticipated to exceed 450 m AGL, are

exempt and may feature only a single/main

deployment event.

If previously flown, any used parachutes, shock

chords, and suspension lines must not exhibit signs

of damage which threatens the safe recovery of the

rocket.

The initial deployment event shall occur at or near

apogee, stabilize the vehicle's attitude (i.e., prevent

or eliminate tumbling), and reduce its descent rate

sufficiently to permit the main deployment event,

yet not so much as to exacerbate wind drift. Any

part, assembly or device, featuring an initial

deployment event, shall result in a descent velocity

of said item of 23-46 m/s.

The main deployment event shall occur at an

altitude no higher than 450 m AGL and reduce the

vehicle's descent rate sufficiently to prevent

excessive damage upon impact with ground. Any

part, assembly or device, featuring a main

deployment event, shall result in a descent velocity

of said item of less than 9 m/s.

Any parachutes or parafoils used must be rated for

the weight of the vehicle and the expected

conditions at deployment.

Parachutes or parafoils intended for the final

descent phase to the ground must not allow a

descent rate that would represent a safety hazard.

Proof by calculation

Proof by reasoned

argumentation

Inspect for Damage

Simple Confirmation

Inspection on site

Proof by reasoned

argument

(Deployment event)

Proof by calculation

(Descent rate)

Proof by previous

testing (Descent

rate)

Proof by reasoned

argumentation

(Deployment event)

Proof by calculation

(Descent rate)

Proof by previous

testing (Descent

rate)

Proof by calculation

Proof by reasoned

argumentation

Proof by previous

testing

Initial Deployment

Event

Main Deployment

Event

Parachutes and

Parafoils

Safe Descent rate

European Rocketry Challenge

–

Design, Test & Evaluation Guide

Page 72 of 88

L 77 - 2022-23 (2. samling) - Bilag 1: Høringssvar og høringsnotat, fra uddannelses- og forskningsministeren

Portugal Space Reference PTS_EDU_EuRoC_ST_000455

Version 03, Date 04.02.2021

Personal Safety

The arming/disarming process must not place the

operator in the predicted path of hot gases, ejecta,

or deployable devices which might result from an

unintentional triggering event

The electronics controlling recovery events must be

activated by externally accessible switches, and do

not require any disassembly of the rocket to either

activate or de-activate.

Each independent set of electronics controlling

recovering events must provide sensory (i.e., visual

or auditory) indication of its activation.

Heavy items - most notably batteries - must be

adequately supported to prevent them becoming

dislodged under anticipated flight loads.

The recovery system shall implement adequate

protection (e.g., fire-resistant material, pistons,

baffles etc.) to prevent hot ejection gases (if

implemented) from causing burn damage to

retaining chords, parachutes, and other vital

components as the specific design demands.

The recovery system rigging (e.g., parachute lines,

risers, shock chords, etc.) shall implement swivel

links at connections to relieve torsion, as the specific

design demands. This will mitigate the risk of torque

loads unthreading bolted connections during

recovery as well as parachute lines twisting up.

Simple check

Activation Devices

Simple confirmation

Positive State

Indication

Acceleration Effects

on Electronics

Simple confirmation

Inspection on site

Simple confirmation

Ejection Gas

Protection

Simple confirmation

Inspection on site

Parachute Swivel

Links

Simple confirmation

Inspection on site

Parachute Coloration

and Markings

When separate parachutes are used for the initial

and main deployment events, these parachutes

should be visually highly dissimilar from one

another. This is typically achieved by using

parachutes whose primary colours contrast those of

the other chute. This will enable ground-based

observers to characterize deployment events more

easily with high-power optics. Utilised parachutes

should use colours providing a clear contrast to a

blue sky and a grey/white cloud cover.

Simple confirmation

European Rocketry Challenge

–

Design, Test & Evaluation Guide

Page 73 of 88

L 77 - 2022-23 (2. samling) - Bilag 1: Høringssvar og høringsnotat, fra uddannelses- og forskningsministeren

Portugal Space Reference PTS_EDU_EuRoC_ST_000455

Version 03, Date 04.02.2021

Non-

parachute/Parafoil

Recovery Systems

Teams exploring other recovery methods (i.e.,

nonparachute or parafoil based) shall mention them

in the dedicated field of the Technical

Questionnaire. The organisers may make additional

requests for information and draft unique

requirements depending on the team's specific

design implementation.

Simple confirmation

Inspection on site

Proof by reasoned

argumentation

In-depth proofing

needed

EDUNDANT

LECTRONICS

At least one redundant recovery system electronics

subsystem shall implement a COTS flight computer.

To be considered COTS, the flight computer

(including flight software) must have been

developed and validated by a commercial third

party.

EuRoC will require teams to implement a common

mandatory GPS tracking and locating device in all

rocket systems featuring a dual-event deployment

and recovery system, specified in more detail in

Appendix C.

Redundant COTS

Recovery Electronics

Simple confirmation

Mandatory Official

GPS Tracking and

Tracking Systems

Simple confirmation

Dissimilar Redundant

Recovery Electronics

There is no requirement that the redundant/backup

system be dissimilar to the primary; however, there

are advantages to using dissimilar primary and

backup systems. Such configurations are less

vulnerable to any inherent environmental

sensitivities, design, or production flaws affecting a

particular component.

No action necessary

AFETY

RITICAL

IRING

All safety critical wiring shall implement a cable

management solution (e.g., wire ties, wiring,

harnesses, cable raceways) which will prevent

tangling and excessive free movement of significant

wiring/cable lengths due to expected launch loads.

This requirement is not intended to negate the

small amount of slack necessary at all

connections/terminals to prevent unintentional

demating due to expected launch loads transferred

into wiring/cables at physical interfaces.

Cable Management

Simple confirmation

Inspection on site

European Rocketry Challenge

–

Design, Test & Evaluation Guide

Page 74 of 88

L 77 - 2022-23 (2. samling) - Bilag 1: Høringssvar og høringsnotat, fra uddannelses- og forskningsministeren

Portugal Space Reference PTS_EDU_EuRoC_ST_000455

Version 03, Date 04.02.2021

Secure Connections

All safety critical wiring/cable connections shall be

sufficiently secure as to prevent de-mating due to

expected launch loads. This will be evaluated by a

"tug test", in which the connection is gently but

firmly "tugged" by hand to verify it is unlikely to

break free in flight.

In case of propellants with a boiling point of less

than -50°C any wiring or harness passing within the

close proximity of a cryogenic device (e.g., valve,

piping, etc.) or a cryogenic tank (e.g., a cable tunnel

next to a LOX tank) shall utilize safety critical wiring

with cryo-compatible insulation (i.e., Teflon, PTFE,

etc.).

All stored-energy devices (aka energetics) used in

recovery systems shall comply with the energetic

device requirements defined in Section 4. of this

document.

Inspection on site

Cryo-compatible

Wire Insulation

Inspection on site

Recovery System

Energetic Devices

Simple confirmation

ECOVERY

YSTEM

ESTING

All recovery system mechanisms shall be

successfully (without significant anomalies) tested

prior to EuRoC, either by flight testing, or through

one or more ground tests of key subsystems. In the

case of such ground tests, sensor electronics will be

functionally included in the demonstration by

simulating the environmental conditions under

which their deployment function is triggered. The

test results and a statement of a successful test,

complete with dates and signatures (at least three)

are considered a mandatory deliverable and annex

to the Technical Report. Failure to deliver this annex

will automatically result in a “denied” flight status.

Ground Test

Demonstration

Proof by previous

testing

European Rocketry Challenge

–

Design, Test & Evaluation Guide

Page 75 of 88

L 77 - 2022-23 (2. samling) - Bilag 1: Høringssvar og høringsnotat, fra uddannelses- og forskningsministeren

Portugal Space Reference PTS_EDU_EuRoC_ST_000455

Version 03, Date 04.02.2021

Optional Flight Test

Demonstration

All recovery system mechanisms shall be

successfully (without significant anomalies) tested

prior to EuRoC, either by flight testing, or through

one or more ground tests of key subsystems. While

not required, a flight test demonstration may be

used in place of ground testing. In the case of such

a flight test, the recovery system flown will verify

the intended design by implementing the same

major subsystem components (e.g., flight

computers and parachutes) as will be integrated

into the launch vehicle intended for EuRoC (i.e., a

surrogate booster may be used). The test results

and a statement of a successful test, complete with

dates and signatures (at least three) are considered

a mandatory deliverable and annex to the Technical

Report. Failure to deliver this annex will

automatically result in a “denied” flight

status.

STORED-ENERGY DEVICES

No action necessary

All energetics shall be “safed” until the rocket is in

the launch position, at which point they may be

"armed". An energetic device is considered safed

when two separate events are necessary to release

the energy of the system. An energetic device is

Energetic

Device considered armed when only one event is necessary

Safing and Arming

to release the energy. For the purpose of this

document, energetics are defined as all

storedenergy devices

–

other than propulsion

systems

–

that have reasonable potential to cause

bodily injury upon energy release. See Section 4.1.

for more information.

All energetic device arming features shall be

externally accessible/controllable. This does not

preclude the limited use of access panels which may

be secured for flight while the vehicle is in the

launch position.

Simple check

Arming Device

Access

Simple confirmation

Inspection on site

European Rocketry Challenge

–

Design, Test & Evaluation Guide

Page 76 of 88

L 77 - 2022-23 (2. samling) - Bilag 1: Høringssvar og høringsnotat, fra uddannelses- og forskningsministeren

Portugal Space Reference PTS_EDU_EuRoC_ST_000455

Version 03, Date 04.02.2021

Arming Device

Location

All energetic device arming features shall be located

on the airframe such that any inadvertent energy

release by these devices will not impact personnel

arming them. For example, the arming key switch

for an energetic device used to deploy a hatch panel

shall not be located at the same airframe clocking

position as the hatch panel deployed by that charge.

Furthermore, it is highly recommended that the

arming mechanism is accessible from ground level,

without the use of ladders or other elevation

Simple confirmation

devices, when the rocket is at a vertical orientation

on the launch rail.

SRAD P

RESSURE

ESSELS

SRAD pressure vessels shall implement a relief

device, set to open at no greater than the proof

pressure specified in the following requirements.

SRAD (including modified COTS) rocket motor

propulsion system combustion chambers are

exempted from this requirement.

SRAD and modified COTS pressure vessels

constructed entirely from isentropic materials (e.g.,

metals) shall be designed to a burst pressure no less

than 2 times the maximum expected operating

pressure, where the maximum operating pressure is

the maximum pressure expected during prelaunch,

flight, and recovery operations.

All SRAD and modified COTS pressure vessels either

constructed entirely from non-isentropic materials

(e.g., fibre reinforced plastics; FRP; composites) or

implementing composite overwrap of a metallic

vessel (i.e., composite overwrapped pressure

vessels; COPV), shall be designed to a burst pressure

no less than 3 times the maximum expected

operating pressure, where the maximum operating

pressure is the maximum pressure expected during

pre-launch, flight, and recovery operations.

Relief Device

Proof by previous

testing

Designed Burst

Pressure for Metallic

Pressure Vessels

Proof by calculation

Proof by reasoned

argumentation

In-depth proofing

needed

Designed Burst

Pressure for

Composite Pressure

Vessels

Proof by calculation

Proof by reasoned

argumentation

In-depth proofing

needed

SRAD P

RESSURE

ESSEL

ESTING

European Rocketry Challenge

–

Design, Test & Evaluation Guide

Page 77 of 88

L 77 - 2022-23 (2. samling) - Bilag 1: Høringssvar og høringsnotat, fra uddannelses- og forskningsministeren

Portugal Space Reference PTS_EDU_EuRoC_ST_000455

Version 03, Date 04.02.2021

Proof Pressure

Testing

SRAD and modified COTS pressure vessels shall be

proof pressure tested successfully (without

significant anomalies) to 1.5 times the maximum

expected operating pressure for no less than twice

the maximum expected system working time, using

the intended flight article(s) (e.g., the pressure

vessel(s) used in proof testing must be the same

one(s) flown at EuRoC). The maximum system

working time is defined as the maximum

uninterrupted time duration the vessel will remain

pressurized during pre-launch, flight, and recovery

operations.

The test results and a statement of a successful test,

complete with dates and signatures (at least three)

are considered mandatory deliverable and annexed

to the Technical Report. Failure to deliver

this annex will automatically result in a “denied”

flight status.

Although there is no requirement for burst pressure

testing, a rigorous verification & validation test plan

typically includes a series of both non-destructive

(i.e., proof pressure) and destructive (i.e., burst

pressure) tests. A series of burst pressure tests

performed on the intended design will be viewed

favourably; however, this will not be considered an

alternative to proof pressure testing of the intended

flight article.

ACTIVE FLIGHT CONTROL SYSTEMS

Launch vehicle active flight control systems shall be

optionally implemented strictly for pitch and/or roll

stability augmentation, or for aerodynamic

"braking". Under no circumstances will a launch

vehicle entered in EuRoC be actively guided towards

a designated spatial target. The organisers may

make additional requests for information and draft

unique requirements depending on the team's

specific design implementation.

Proof by previous

testing

Optional Burst

Pressure Testing

No action necessary

Restricted Control

Functionality

Simple confirmation

European Rocketry Challenge

–

Design, Test & Evaluation Guide

Page 78 of 88

L 77 - 2022-23 (2. samling) - Bilag 1: Høringssvar og høringsnotat, fra uddannelses- og forskningsministeren

Portugal Space Reference PTS_EDU_EuRoC_ST_000455

Version 03, Date 04.02.2021

Unnecessary for

Stable Flight

Launch vehicles implementing active flight controls

shall be naturally stable without these controls

being implemented (e.g., the launch vehicle may be

flown with the control actuator system [CAS]

—

including any control surfaces

—

either removed or

rendered inert and mechanically locked, without

becoming unstable during ascent). Attitude Control

Systems (ACS) will serve only to mitigate the small

perturbations which affect the trajectory of a stable

rocket that implements only fixed aerodynamic

surfaces for stability. The organisers may make

additional requests for information and draft

unique requirements depending on the team's

specific design implementation.

Control Actuator Systems (CAS) shall mechanically

lock in a neutral state whenever either an abort

signal is received for any reason, primary system

power is lost, or the launch vehicle's attitude

exceeds 30° from its launch elevation. Any one of

these conditions being met will trigger the fail-safe,

neutral system state. A neutral state is defined as

one which does not apply any moments to the

launch vehicle (e.g., aerodynamic surfaces trimmed

or retracted, gas jets off, etc.).

CAS shall mechanically lock in a neutral state until

either the mission’s boost phase has ended (i.e., all

propulsive stages have ceased producing thrust),

the launch vehicle has crossed the point of

maximum aerodynamic pressure (i.e., max Q) in its

trajectory, or the launch vehicle has reached an

altitude of 6.000 m AGL. Any one of these conditions

being met will permit the active system state. A

neutral state is defined as one which does not apply

any moments to the launch vehicle (e.g.,

aerodynamic surfaces trimmed or retracted, gas jets

off, etc.).

Proof by reasoned

argumentation

Inspection on site

Designed to Fail Safe

Proof by reasoned

argumentation

Inspection on site

Boost Phase

Dormancy

Proof by reasoned

argumentation

Inspection on site

European Rocketry Challenge

–

Design, Test & Evaluation Guide

Page 79 of 88

L 77 - 2022-23 (2. samling) - Bilag 1: Høringssvar og høringsnotat, fra uddannelses- og forskningsministeren

Portugal Space Reference PTS_EDU_EuRoC_ST_000455

Version 03, Date 04.02.2021

Active Flight Control

System Electronics

Wherever possible, all active control systems should

comply with requirements and goals for "redundant

electronics" and "safety critical wiring" as recovery

systems

—

understanding that in this case

"initiation" refers CAS commanding rather than a

recovery event. Flight control systems are exempt

from the requirement for COTS redundancy, given

that such components are generally unavailable as

COTS to the amateur highpower rocketry

community.

All stored-energy devices used in an active flight

control system (i.e., energetics) shall comply with

the energetic device requirements defined in

Section 4. of this document.

AIRFRAME STRUCTURES

Launch vehicles shall be adequately vented to

prevent unintended internal pressures developed

during flight from causing either damage to the

airframe or any other unplanned configuration

changes. Typically, a 3 mm to 5 mm hole is drilled in

the booster section just behind the nosecone or

payload shoulder area, and through the hull or

bulkhead

any

similarly

isolated

compartment/bay.

Simple confirmation

Active Flight Control

System Energetics

Simple confirmation

Adequate Venting

Simple confirmation

Inspection on site

VERALL

TRUCTURAL

NTEGRITY

Upon request, the flier should provide the inspector

with hardcopy checklist procedures for the rocket's

assembly and integration for flight - including

selfinspection/verification steps which make

individual team members accountable to one

another for having completed the preceding

process(es).

PVC (and similar low-temperature polymers), Public

Missiles Ltd. (PML) Quantum Tube components

shall not be used in any structural (i.e., load bearing)

capacity, most notably as load bearing eyebolts,

launch vehicle airframes, or propulsion system

combustion chambers.

Checklist

Simple confirmation

Inspection on site

Material Selection

No action necessary

(for stainless steel

components)

Simple confirmation

European Rocketry Challenge

–

Design, Test & Evaluation Guide

Page 80 of 88

L 77 - 2022-23 (2. samling) - Bilag 1: Høringssvar og høringsnotat, fra uddannelses- og forskningsministeren

Portugal Space Reference PTS_EDU_EuRoC_ST_000455

Version 03, Date 04.02.2021

Load Bearing

Eyebolts and U-bolts

All load bearing eyebolts shall be of the closed-eye,

forged type

—

NOT of the open eye, bent wire type.

Furthermore, all load bearing eyebolts and U-Bolts

shall be steel or stainless steel. This requirement

extends to any bolt and eye-nut assembly used in

place of an eyebolt.

Airframe joints which implement "coupling tubes"

should be designed such that the coupling tube

extends no less than one body calibre on either side

of the joint

—

measured from the separation plane.

Regardless of implementation (e.g., RADAX or other

join types) airframe joints will be "stiff" (i.e., prevent

bending).

Launch lugs (i.e., rail guides) should implement

"hard points" for mechanical attachment to the

launch vehicle airframe. These hardened/reinforced

areas on the vehicle airframe, such as a block of

wood installed on the airframe interior surface

where each launch lug attaches, will assist in

mitigating lug "tear outs" during operations. The aft

most launch lug shall support the launch vehicle's

fully loaded launch weight while vertical. At EuRoC,

competition officials will require teams to lift their

launch vehicles by the rail guides and/or

demonstrate that the bottom guide can hold the

vehicle's weight when vertical. This test needs to be

completed successfully before the admittance of

the team to Launch Readiness Review.

All teams shall perform a “launch rail fit check” as a

part of the flight preparations (the Launch

Readiness Review), before going to the launch

range. This requirement is particularly important if

a team is not bringing their own launch rail, but

instead relying on EuRoC provided launch rails.

The rail guides must be firmly attached to the rocket

without evidence of cracking in the joints, and the

aft most guide attachment must be sufficient to

bear the rocket's entire mass when erected.

No action necessary

(for stainless steel)

Inspection on site

Implementing

Coupling Tubes

Simple confirmation

Proof by reasoned

argumentation

Launch Lug

Mechanical

Attachment

Inspection on site

Proof by previous

testing

Launch Rail Fit Check

Inspection on site

Rail Guide

Attachment

Inspection on site

European Rocketry Challenge

–

Design, Test & Evaluation Guide

Page 81 of 88

L 77 - 2022-23 (2. samling) - Bilag 1: Høringssvar og høringsnotat, fra uddannelses- og forskningsministeren

Portugal Space Reference PTS_EDU_EuRoC_ST_000455

Version 03, Date 04.02.2021

Slip-fit Joints

Joints intended to separate in flight cannot become

separated when loaded by their own weight alone,

and the Flier should demonstrate cognizance of

shear pin design (if implemented).

All joints - both separating and non-separating in

flight - must be "stiff", so as to eliminate any visible

airframe bending.

The fins must be firmly attached to the rocket

without evidence of cracking in the joints.

("Hairline" cracks may be acceptable if the fins are

not loose or, if the fins are mounted using the

"through-the-wall" [TTW] construction technique.

The fins must exhibit no shifting and minimal

deflection (i.e., bending) when handled.

The fins must exhibit little-to-no indication of

damage due to moisture penetration or excessive

thermal cycling during storage or transport - leading

to out of tolerance dimensional changes in the part.

Proof by reasoned

argumentation

Joint Stiffness

Inspection on site

Fin Attachment

Inspection on site

Fin Stiffness

Inspection on site

Fin "Warpage"

Inspection on site

RF T

RANSPARENCY

European Rocketry Challenge

–

Design, Test & Evaluation Guide

Page 82 of 88

L 77 - 2022-23 (2. samling) - Bilag 1: Høringssvar og høringsnotat, fra uddannelses- og forskningsministeren

Portugal Space Reference PTS_EDU_EuRoC_ST_000455

Version 03, Date 04.02.2021

RF Window Location

Any internally mounted RF transmitter, receiver or

transceiver, not having the applicable antenna or

antennas mounted externally on the airframe, shall

employ “RF windows" in the airframe shell plating

(typically glass fibre panels), enabling RF devices

with antennas mounted inside the airframe, to

transmit the signal though the airframe shell. RF

windows in the flight vehicle shell shall be a 360°

circumference and be at least two body diameters

in length. The internally mounted RF antenna(s)

shall be placed at the midpoint of the RF window

section, facilitating maximizing the azimuth

radiation

pattern.

RF transmitter, receivers or transceivers are not

allowed to be mounted externally. Externally

mounted antennas are allowed, but only if at least

two antennas are mounted on opposite sides of the

airframe, thus retaining circumferential symmetry

and covering sufficient transmission area,

transmitting or receiving identical signals. As

popular as carbon fibre is for the construction of

strong and lightweight airframes, it is also

conductive and will significantly shield and/or

degrade RF signals, which is unacceptable.

The team's Team ID (a number assigned by EuRoC

prior to the competition event), project name, and

academic affiliation(s) shall be clearly identified on

the launch vehicle airframe. The Team ID especially,

will be prominently displayed (preferably visible on

all four quadrants of the vehicle, as well as fore and

aft), assisting competition officials to positively

identify the project hardware with its respective

team throughout EuRoC.

Simple confirmation

Identifying Markings

No action necessary

European Rocketry Challenge

–

Design, Test & Evaluation Guide

Page 83 of 88

L 77 - 2022-23 (2. samling) - Bilag 1: Høringssvar og høringsnotat, fra uddannelses- og forskningsministeren

Portugal Space Reference PTS_EDU_EuRoC_ST_000455

Version 03, Date 04.02.2021

Other Markings

There are no requirements for airframe coloration

or markings beyond those specified in Section 6.4.

of this document. However, EuRoC offers the

following recommendations to student teams:

mostly white or lighter tinted colour (e.g., yellow,

red, orange, etc.) airframes are especially conducive

to mitigating some of the solar heating experienced

in the EuRoC launch environment. Furthermore,

high-visibility schemes (e.g., highcontrast black,

orange, red, etc.) and roll patterns (e.g., contrasting

stripes, “V” or “Z” marks, etc.) may allow ground-

based observers to more easily track and record the

launch vehicle’s trajectory with high-power

optics.

PAYLOAD

Payloads may be deployable or remain attached to

the launch vehicle throughout the flight. Deployable

payloads shall incorporate an independent recovery

system, reducing the payload's descent velocity to

less than 9 m/s before it descends through an

altitude of 450 m AGL. Deployable payloads without

two-stage recovery systems (drogue and main

chute, like the rockets) will be subjective to

considerable drift during descent.

Payloads implementing independent recovery

systems shall comply with the same requirements

and goals as the launch vehicle for "redundant

electronics" and "safety critical wiring".

Payloads implementing independent recovery

systems shall comply with the same requirements

and goals as the launch vehicle for "recovery system

testing".

No action necessary

Payload recovery

Proof by calculation

Proof by reasoned

argumentation

Proof by previous

testing

Payload Recovery

System

Electronics

and

Safety Critical

Wiring

Payload Recovery

System Testing

Inspection on site

Simple confirmation

European Rocketry Challenge

–

Design, Test & Evaluation Guide

Page 84 of 88

L 77 - 2022-23 (2. samling) - Bilag 1: Høringssvar og høringsnotat, fra uddannelses- og forskningsministeren

Portugal Space Reference PTS_EDU_EuRoC_ST_000455

Version 03, Date 04.02.2021

Deployable Payload

GPS Tracking

Required

It must be noted that deployable payloads are

equivalent to flight vehicle bodies and sections, in

that they can be difficult to locate after landing. All

deployable payloads shall feature the same

mandatory GPS tracking system as all rockets and

rocket stages as specified in the Appendix C: Official

Altitude Logging and Tracking System. The GPS

locator ID must differ from the ID of the launch

vehicle.

All stored-energy devices (i.e., energetics) used in

payload systems shall comply with the energetic

device requirements defined in Section 4. of this

document.

LAUNCH AND ASCENT TRAJECTORY REQUIREMENTS

Launch vehicles shall nominally launch at an

elevation angle of 84° ±1° and a launch azimuth

defined by competition officials at EuRoC.

Competition officials reserve the right to require

certain vehicles' launch elevation be as low a 70°, if

flight safety issues are identified during pre-launch

activities.

Launch vehicles shall have sufficient velocity upon

"departing the launch rail" to ensure they will follow

predictable flight paths. In lieu of detailed analysis,

a rail departure velocity of at least 30 m/s is

generally acceptable. Alternatively, the team may

use detailed analysis to prove stability is achieved at

a lower rail departure velocity 20 m/s either

theoretically (e.g., computer simulation) or

empirically (e.g., flight testing).

Launch vehicles shall remain "stable" for the entire

ascent. Stable is defined as maintaining a static

margin of at least 1.5 to 2 body calibres, regardless

of CG movement due to depleting consumables and

shifting centre of pressure (CP) location due to wave

drag effects (which may become significant as low

as 0.5 Mach). Not falling below 2 body calibres will

be considered nominal, while falling below 1.5 body

calibres will be considered a loss of stability.

Simple confirmation

Payload Energetic

Devices

Simple confirmation

Launch Azimuth and

Elevation

Simple check

Launch Stability

Proof by calculation

Ascent Stability

Proof by calculation

European Rocketry Challenge

–

Design, Test & Evaluation Guide

Page 85 of 88

L 77 - 2022-23 (2. samling) - Bilag 1: Høringssvar og høringsnotat, fra uddannelses- og forskningsministeren

Portugal Space Reference PTS_EDU_EuRoC_ST_000455

Version 03, Date 04.02.2021

Over-stability

All launch vehicles should avoid becoming

"overstable" during their ascent. A launch vehicle

may be considered over-stable with a static margin

significantly greater than 2 body calibres (e.g.,

greater than 6 body calibres).

Upon request, the flier should either provide a hard

copy, or demonstrate on a portable computer, a

3degreee-of-freedom (3DoF) simulation (or better)

of the rocket's nominal trajectory.

The fins should be mounted parallel to the roll axis

of the rocket, or (if canted or otherwise roll

inducing) the Flier must demonstrate cognizance of

the predicted roll behaviour and its effects.

Proof by calculation

Flight Simulation

In-depth proofing

needed

Fin Alignment

Inspection on site

Any delays implemented between staging events

must not be so long as to significantly risk the rocket

Staging Event

Sequence and Timing having "arced-over" into an unsafe orientation -

typically by "gravity turn".

TEAM-PROVIDED LAUNCH SUPPORT EQUIPMENT

If possible/practicable, teams should make their

launch support equipment man-portable over a

short distance (a few hundred metres).

Environmental considerations at the launch site

permit only limited vehicle use beyond designated

roadways, campgrounds, and basecamp areas.

Team provided launch rails shall implement the

nominal launch elevation specified in Section 8.1. of

this document and, if adjustable, not permit launch

at angles either greater than the nominal elevation

or lower than 70°.

All team provided launch control systems shall be

electronically operated and have a maximum

operational range of no less than 650 metres from

the launch rail. The maximum operational range is

defined as the range at which launch may be

commanded reliably.

Proof by calculation

Equipment

Portability

Simple confirmation

Launch Rail Elevation

Inspection on site

Operational Range

No action necessary

European Rocketry Challenge

–

Design, Test & Evaluation Guide

Page 86 of 88

L 77 - 2022-23 (2. samling) - Bilag 1: Høringssvar og høringsnotat, fra uddannelses- og forskningsministeren

Portugal Space Reference PTS_EDU_EuRoC_ST_000455

Version 03, Date 04.02.2021

Fault Tolerance and

Arming

All team provided launch control systems shall be at

least single fault tolerant by implementing a

removable safety interlock (i.e., a jumper or key to

be kept in possession of the arming crew during

arming) in series with the launch switch.

All team provided launch control systems shall

implement ignition switches of the momentary,

normally open (also known as "dead man") type so

that they will remove the signal when released.

Mercury or "pressure roller" switches are not

permitted anywhere in team provided launch

control systems.

EQUIPMENT

All teams must bring any Personal Protection

Equipment (PPE) required for all preparation- and

launch activities. EuRoC does not have a supply of

spare PPE. PPE includes, but is not limited to, safety

goggles, gloves, safety shoes, hardhats, ear

protection, cryo-protection, etc.

Inspection on site

Safety Critical

Switches

Simple confirmation

Communication

Equipment

No action necessary

Personal Protection

Equipment

All teams must bring any Personal Protection

Equipment (PPE) required for all preparation- and

launch activities. EuRoC does not have a supply of

Simple confirmation

spare PPE. PPE includes, but is not limited to, safety

goggles, gloves, safety shoes, hardhats, ear

protection, cryo-protection, etc.

All teams are encouraged to provide each

participating team member with a suitable

“field/day pack”, which is kept close at hand (or

worn) during launch days. Due to the possibility of

strong sunlight and high temperatures even in

October, some of these provisions are intended to

get students through a hot and dry day in the field,

while other provisions are intended to enable

student teams to continue efficient operation after

loss of daylight after a quick sun-down and a

resulting sudden and significant drop in ambient

temperature.

Table 4: Legend for de-scoping FRR checklist.

Field Equipment

No action necessary

EGEND FOR DE

SCOPING FEEDBACK

European Rocketry Challenge

–

Design, Test & Evaluation Guide

Page 87 of 88

L 77 - 2022-23 (2. samling) - Bilag 1: Høringssvar og høringsnotat, fra uddannelses- og forskningsministeren

Portugal Space Reference PTS_EDU_EuRoC_ST_000455

Version 03, Date 04.02.2021

This requirement is very important

This requirement is important

This requirement is of lesser importance

Table 5: Legend for actions to be taken on the FRR checklist.

CTIONS TO BE TAKEN

No action necessary

Simple confirmation

Simple check

Inspection on site

Proof by reasoned

argumentation

“I see you used stainless steel here. Okay, fine”

“Are you using non-toxic propellants?” – “Yes, we are”

“Is everybody at least 15 m away when the ground-start

ignition

circuit is arming?” – “Okay now, yes”

“Are all the critical wiring/cable connections sufficiently secured?” –

“I will have a look, ah I see, yes”

“Can you tell me about your process of offloading propellant in case

of a launch abort?” – “Okay, sounds reasonable, this should work.”

“Have you tested the

pressure vessels to 1.5 the maximum expected

operating pressure?” – “Okay, I will have a look at the results and

understand if everything has been tested appropriately.”

“Regarding the launch stability, have you calculated the

lower rail

departure velocity? How did you do it? What is the result?” – “Okay,

I see and understand the calculation, this will work then.”

“How does this design feature work?” – “Okay, so you are not

certain, and I do not understand on site, so let us go to the CAD

model and check.”

Proof by previous testing

Proof by calculation

In-depth proofing needed

European Rocketry Challenge

–

Design, Test & Evaluation Guide

Page 88 of 88