Space systems — Thermal vacuum environmental testing

This document provides methods and specifies general requirements for spacecraft level thermal balance tests (TBT) and thermal vacuum tests (TVT). It also provides basic requirements for test facilities, test procedures, test malfunction interruption emergency handling and test documentation. The methods and requirements can be used as a reference for subsystem-level and unit-level test article.

Systèmes spatiaux — Essais environnementaux sous vide thermique

General Information

Status

Published

Publication Date

30-Jan-2023

ICS

49.140 - Space systems and operations

Technical Committee

ISO/TC 20/SC 14 - Space systems and operations

Drafting Committee

ISO/TC 20/SC 14/WG 2 - System requirements, verification and validation, interfaces, integration, and test

Current Stage

6060 - International Standard published

Start Date

31-Jan-2023

Due Date

10-Sep-2022

Completion Date

31-Jan-2023

Ref Project

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ISO/FDIS 24412:2022(E)
ISO TC 20/SC 14/WG 2
Date: 2022-09-1910-25
Secretariat: ANSI/AIAA
Space systems — Thermal vacuum environmental testing
---------------------- Page: 1 ----------------------
ISO/FDIS 24412:2022(E)
© ISO 2022

part of this publication may be reproduced or utilized otherwise in any form or by any means,

electronic or mechanical, including photocopying, or posting on the internet or an intranet, without

prior written permission. Permission can be requested from either ISO at the address below or ISO’s

member body in the country of the requester.
ISO copyright office
CP 401 • Ch. de Blandonnet 8
CH-1214 Vernier, Geneva
Phone: +41 22 749 01 11
Email: copyright@iso.org
Website: www.iso.org
Published in Switzerland
ii © ISO 2022 – All rights reserved
---------------------- Page: 2 ----------------------
ISO/FDIS 24412:2022(E)
Contents

Foreword ........................................................................................................................................................................... v

Introduction ................................................................................................................................................................... vi

1 Scope ........................................................................................................................................................................... 1

2 Normative references ........................................................................................................................................... 1

3 Terms and definitions .......................................................................................................................................... 1

4 Symbols and abbreviations ................................................................................................................................ 2

5 Test purpose ............................................................................................................................................................ 2

5.1 Thermal balance test ............................................................................................................................................ 2

5.2 Thermal vacuum test ............................................................................................................................................ 2

5.2.1 General purpose ............................................................................................................................................... 2

5.2.2 Qualification test .............................................................................................................................................. 3

5.2.3 Proto-flight test ................................................................................................................................................ 3

5.2.4 Acceptance test ................................................................................................................................................. 3

6 Test methods ........................................................................................................................................................... 3

6.1 Thermal balance test ............................................................................................................................................ 3

6.1.1 Test description ............................................................................................................................................... 3

6.1.2 Test conditions ................................................................................................................................................. 5

6.1.3 Basic requirements of test facilities ......................................................................................................... 6

6.1.4 Monitoring during TBT .................................................................................................................................. 7

6.2 Thermal vacuum test ............................................................................................................................................ 7

6.2.1 Test description ............................................................................................................................................... 7

6.2.2 Test conditions ................................................................................................................................................. 9

6.2.3 Basic requirements of test facilities ...................................................................................................... 11

6.2.4 Monitoring during TVT .............................................................................................................................. 11

7 Test facility ........................................................................................................................................................... 12

7.1 Laboratory environment ................................................................................................................................. 12

7.2 Laboratory infrastructure ............................................................................................................................... 12

7.3 Test system ........................................................................................................................................................... 12

7.3.1 Overview ......................................................................................................................................................... 12

7.3.2 Chamber system ........................................................................................................................................... 13

7.3.3 Vacuum system ............................................................................................................................................. 13

7.3.4 Thermal system ............................................................................................................................................ 14

7.3.5 Data acquisition system ............................................................................................................................. 16

7.3.6 MGSE ................................................................................................................................................................. 17

7.3.7 Contamination measurement and control system ........................................................................... 17

8 Test requirements .............................................................................................................................................. 17

8.1 Test tolerance and accuracy ........................................................................................................................... 17

8.2 Test configuration .............................................................................................................................................. 18

8.3 Temperature and heat flux measurement ................................................................................................ 18

8.3.1 General ............................................................................................................................................................. 18

8.3.2 Location of temperature monitoring point for test article ........................................................... 19

8.3.3 Location of temperature monitoring point for test equipment .................................................. 19

8.4 Heating device selection .................................................................................................................................. 19

8.5 Safety requirements .......................................................................................................................................... 19

9 Test procedure .................................................................................................................................................... 20

9.1 Test flow ................................................................................................................................................................ 20

9.2 Test procedure .................................................................................................................................................... 20

9.2.1 Before test ....................................................................................................................................................... 20

iv © ISO 2022 – All rights reserved
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ISO/FDIS 24412:2022(E)

9.2.2 Test implementation ................................................................................................................................... 21

9.2.3 After test .......................................................................................................................................................... 22

10 Test interruption and handling ..................................................................................................................... 22

10.1 Interruption .................................................................................................................................................... 22

10.1.1 Test facility malfunction ............................................................................................................................ 22

10.1.2 Test article malfunction ............................................................................................................................. 23

10.2 Interruption handling ................................................................................................................................. 23

11 Test documentation ........................................................................................................................................... 23

Annex A (informative) Main characteristic of a solar simulator ............................................................... 24

Annex B (informative) An example of IR heater design flow for absorbed flux simulation

method in TBT ............................................................................................................................................... 26

Bibliography ................................................................................................................................................................. 30

ISO (the International Organization for Standardization) is a worldwide federation of national

standards bodies (ISO member bodies). The work of preparing International Standards is normally

carried out through ISO technical committees. Each member body interested in a subject for which a

technical committee has been established has the right to be represented on that committee.

International organizations, governmental and non-governmental, in liaison with ISO, also take part in

the work. ISO collaborates closely with the International Electrotechnical Commission (IEC) on all

matters of electrotechnical standardization.

The procedures used to develop this document and those intended for its further maintenance are

described in the ISO/IEC Directives, Part 1. In particular, the different approval criteria needed for the

different types of ISO documents should be noted. This document was drafted in accordance with the

editorial rules of the ISO/IEC Directives, Part 2 (see www.iso.org/directives).

Attention is drawn to the possibility that some of the elements of this document may be the subject of

patent rights. ISO shall not be held responsible for identifying any or all such patent rights. Details of

any patent rights identified during the development of the document will be in the Introduction and/or

on the ISO list of patent declarations received (see www.iso.org/patents).

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expressions related to conformity assessment, as well as information about ISO's adherence to the

World Trade Organization (WTO) principles in the Technical Barriers to Trade (TBT), see

www.iso.org/iso/foreword.html.

This document was prepared by Technical Committee ISO/TC 20, Aircraft and space vehicles,

Subcommittee SC 14, Space systems and operations.

Any feedback or questions on this document should be directed to the user’s national standards body. A

complete listing of these bodies can be found at www.iso.org/members.html.
vi © ISO 2022 – All rights reserved
---------------------- Page: 6 ----------------------
ISO/FDIS 24412:2022(E)
Introduction

The on-orbit environments of spacecraft, with their vacuum state, cryogenic and black background, and

complex heat transfer, are harsher and more complex than the ground environment. They have a strong

impact on the success of spacecraft mission. Thermal balance tests (TBT) and thermal vacuum tests

(TVT) at spacecraft level are conducted to ensure the units in spacecraft operate normally in specified

pressure and thermal range.

This document provides methods and specifies general requirements for spacecraft level thermal

balance tests and thermal vacuum tests. However, the technical requirements in this document can be

tailored by the parties for some special spacecraft, such as manned vehicle, deep space explorer, extra-

terrestrial body lander or the satellites with emphasis on low-cost and fast delivery, which are

characterized by extensive use of non-space-qualified commercial-off-the-shelf (COTS) units.

This document acts as a supplement to ISO 15864 and ISO 19683. It is applicable to test project

designers and test organizations. It also serves as a reference for spacecraft designers and test facility

manufacturers.
© ISO 2022 – All rights reserved vii
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FINAL DRAFT INTERNATIONAL STANDARD ISO/FDIS 24412:2022(E)
Space systems — Thermal vacuum environmental testing
1 Scope

This document provides methods and specifies general requirements for spacecraft level thermal

balance tests (TBT) and thermal vacuum tests (TVT). It also provides basic requirements for test

facilities, test procedures, test malfunction interruption emergency handling and test documentation.

The methods and requirements can be used as a reference for subsystem-level and unit-level test

article.
2 Normative references

The following documents are referred to in the text in such a way that some or all of their content

constitutes requirements of this document. For dated references, only the edition cited applies. For

undated references, the latest edition of the referenced document (including any amendments) applies.

ISO 15864:2021, Space systems — General test methods for spacecraft, subsystems and units

ISO 17566:2011, Space systems — General test documentation
3 Terms and definitions
For the purposes of this document, the following terms and definitions apply.

ISO and IEC maintain terminology databases for use in standardization at the following addresses:

— ISO Online browsing platform: available at https://www.iso.org/obp
— IEC Electropedia: available at https://www.electropedia.org/
3.1
maximum predicted temperature

highest temperature that can be expected to occur during the entire life cycle of the subsystem

(3.4)/unit (3.8) in all operational modes plus an uncertainty factor
3.2
minimum predicted temperature

lowest temperature that can be expected to occur during the entire life cycle of the subsystem (3.4)/unit

(3.8) in all operational modes plus an uncertainty factor
3.3spacecraft3
spacecraft

integrated set of subsystems (3.4) and units (3.8) designed to perform specific tasks or functions in

space
3.4subsystem4
subsystem

assembly of functionally related units (3.8), which is dedicated to specific functions of a system

© ISO 2022 – All rights reserved 1
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ISO/FDIS 24412:2022(E)
3.5
thermal balance test

test conducted to verify the adequacy of the thermal model and the adequacy of the thermal design

3.6
thermal uncertainty margin

temperature margin included in the thermal analysis of units (3.8), subsystems (3.4) and spacecraft (3.3)

to account for uncertainties in modelling parameters such as complex view factors, surface properties,

contamination, radiation environments, joint conduction and interface conduction and ground

simulation
3.7
thermal vacuum test

test conducted to demonstrate the capability of the test item to operate according to requirements in

vacuum at predefined temperature condition

NOTENote 1 to entry: Temperature conditions can be expressed asin terms of temperature level, gradient,

variation and number of high-low temperature cycles.
3.8
unit

lowest level of hardware assembly that works with specified complex electrical, thermal and/or

mechanical functions
4 Symbols and abbreviated terms
AT acceptance test
AT acceptance testelectrical ground support equipment
EGSE
FM flight model
IR infrared
MGSE mechanical ground support equipment
OSR optical solar reflector
PFT proto-flight test
QT qualification test
TBT thermal balance test
TQCM temperature-controlled quartz crystal microbalances
TVT thermal vacuum test
UPS uninterruptible power supplyultraviolet
UV ultraviolet
2 © ISO 2022 – All rights reserved
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ISO/FDIS 24412:2022(E)
5 Test purpose
5.1 Thermal balance test

The purpose of the thermal balance test is to provide the data necessary to verify the analytical thermal

model and demonstrate the ability of the spacecraft thermal control subsystem to maintain the

specified operational temperature limits of the units throughout the entire spacecraft.

5.2 Thermal vacuum test
5.2.1 General purpose

The purpose of the thermal vacuum test is to demonstrate the ability of the test item and its units to

meet the design requirements under vacuum conditions and temperature extremes that simulate those

predicted for flight. TVT detects material, process and workmanship defects that would respond to

vacuum and thermal stress conditions.

The test level and test duration isare described in subclause 6.2.2.1 and 6.2.2.2 respectively.

5.2.2 Qualification test

During the qualification test (QT), the thermal vacuum test serves to validate the performance of the

qualification model (QM) in the intended environments with the specified qualification margins.

5.2.3 Proto-flight test

During the proto-flight test (PFT), the thermal vacuum test serves to validate the performance of the

proto-flight model (PFM) on the first flight in the intended environments with the specified proto-flight

margins.
5.2.4 Acceptance test

During the acceptance test (AT), the thermal vacuum test serves to validate the performance of the

flight model (FM)，), except the one used as pro-flight, in the intended environments with the specified

acceptance margins.
6 Test methods
6.1 Thermal balance test
6.1.1 Test description

The on-orbit external thermal flux simulation can be conducted by one of the following methods:

a) Incident flux method

The intensity, spectral content and angular distribution of the incident solar, albedo and planetary

irradiation encountered by on-orbit spacecraft are simulated by using solar simulator system, shown in

Figure 1 or using the other method (e.g.,. with axial location of solar simulator).

The solar simulator is composed of the xenon lamp, the filter and the collimator. Generally, the test

article is installed on a motion simulator (rotating platform) to simulate the different attitudes on orbit.

For the requirements of a solar simulation system, see 7.3.4.5. For the main characteristic of a solar

simulator, see Annex A.
© ISO 2022 – All rights reserved 3
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ISO/FDIS 24412:2022(E)
Key
1 shroud 2 motion simulator 3 test article
4 solar simulator 5 vacuum chamber 6 collimator
Figure 1 — Solar simulation method

This method is suitable for spacecraft with complex shapes and large differences in surface thermal

characteristics. It can provide incident illumination with matching spectral, uniformity and stability of

irradiance, divergence angle for the thermal test of the spacecraft. However, it is difficult to simulate the

effects for performance degradation of thermal control coatings at end of lifetime. This method may be

restricted for the effect of reflection light or heat from surfaces of shroud and MGSE, large operating

cost and heat pipes on-board normally working horizontally.
b) Absorbed flux method

The absorbed solar, albedo and planetary irradiation for on-orbit spacecraft, are simulated by using

infrared (IR) heaters (cage, lamps, calrods and thermal plate) with their spectrum adjusted to the

external thermal coating properties, or by using film heaters attached to spacecraft surfaces with the

absorbed heat flux controlled by electrical power, shown in Figure 2. For the requirements for IR heater

and film heater, see 7.3.4.3 and 7.3.4.4. TheAnnex B describes the design flow of an IR heater in the

absorbed flux method in TBT can be referred to Annex B.
4 © ISO 2022 – All rights reserved
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ISO/FDIS 24412:2022(E)
Key
1 vacuum chamber 2 shroud 3 IR cage or IR thermal plate
4 test article 5 IR lamp/calrod array
Figure 2 — Absorbed flux method

This method is suitable for spacecraft with simple shapes and similar in surface thermal characteristics.

It has the advantage of high reliability, low manufacturing and operation cost. It may be restricted for

the containment released from MGSE, limited temperature ramp and the numbers of heating loops or

electrical power.
c) The combination of methods a) and b)

The combination of the methods a) and b) can be used for heat flux simulation of different surfaces of

the test article in TBT.
Generally, the following shall be considered during test article design:

— The profile, structures, materials, instrument and device layout, cable network, various thermal

control measures, envelop dimension, surface state, installation and connection mode, internal heat

sources, thermal capacity shall meet the requirements of thermal design and simulation.

— The thermal simulation model of spacecraft or its units may be designed specially, whose thermal

capacity and heat consumption are in accord with that on orbit.

— The large antenna, solar array and other external components may not participate in the test, but

their radiation heat effects shall be evaluated. Conduction heat shall be simulated on installation

interfaces by proper heat insulation, heat leakage compensation, or constant temperature.

— Additional radiation flux created by thermal vacuum chamber, MGES and heating devices frames

shall be taken into account.

— If the natural convection effects cannot be ignored under the ground gravitation condition,

pressurized cabin convection boundary shall be simulated by adjusting the gas temperature,

pressure and velocity on the units’ surface to ensure the heat transfer is equivalent.

— The propellant tank is filled with protective gas.
© ISO 2022 – All rights reserved 5
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ISO/FDIS 24412:2022(E)
6.1.2 Test conditions
6.1.2.1 Test cases design

TBT cases depend on the mission, spacecraft design, spacecraft operational modes, and times required

to reach stabilization. According to the internal heat source heating mode, orbital heating mode and

other thermal boundary conditions, there are four types of operating cases.
a) Case 1

Internal heat source, simulative orbital heating and other thermal boundary conditions are

constant;
b) Case 2

Internal heat source works in a set periodic change mode, while the simulative orbital heating and

other thermal boundary conditions are constant;
c) Case 3

Internal heat source works in a set periodic change mode; the simulative orbital heating and other

thermal boundary conditions are in the periodic orbit change mode;
d) Case 4

Internal heat source, simulative orbital heating mode or other thermal boundary conditions are in

the aperiodic change during the specified phase.

For b) and c), the cyclic test for several periods can be repeated either with the heat source

operating mode and simulative orbital heating mode in one orbit period until the temperature of

test model is steady periodically, or with several orbit periods as one test period until the

temperature of test model is steady periodically.
The design principles of the test cases are as follows.

— Test phases shall simulate cold and hot conditions to verify all aspects of the thermal hardware and

software, including heater operation, radiator sizing, and critical heat transfer paths.

— Test cases shall obtain sufficient critical parameters required for thermal analytical model

verification and flight mission indication.

— To validate the adequacy of the thermal control design, the cases shall contain hot case and cold

case at least. Consideration should be given for testing an “off-nominal” case such as a safehold or a

survival mode.

— Generally, the test for the only purpose of verifying thermal analytical model shall contain transient

case.

— Transient case shall be set when the influence of on-orbit heat flux or other thermal boundary

conditions on spacecraft temperature increases with time.
6 © ISO 2022 – All rights reserved
---------------------- Page: 13 ----------------------
ISO/FDIS 24412:2022(E)
6.1.2.2 Temperature stabilization

The exposure shall be long enough for the test article to reach temperature stabilization so that

temperature distributions are ensured in the steady-state conditions. The test temperature shall be

considered as stabilized, in case that

a) temperature monitored at the test article is within the allowed tolerance around the specified test

temperature;

b) temperature change rate is lower than the value allowed for stable conditions.

Steady-state conditions shall be defined in test specification. The temperature fluctuation should be

within ±0,5 °C over 4 h; or monotonous change should be less than 0,1 °C/ h over 4 h. Meanwhile the

fluctuation of other temperature points can be used as a reference.
6.1.3 Basic requirements of test facilities
a) The test pressure should be no higher than 1,33 × 10 Pa.
b) The shroud surface temperature should be no higher than 100 K.
c) The distance between testing equipment and a test item shall ensure:

- — convenience while performing preparation and completion operations with a test item;

- — availability of required uniformity of heat fluxes, incident on a test item surface when performing

tests.

d) ShroudThe shroud surface shall be painted with high-emissivity black coating whose solar

absorption ratio shall be higher than 0,95 and hemispheric emissivity shall be higher than 0,9.

e) The requirementsrecommendations in a) and b) should be reassessed according to the specified

elements such as external and internal thermal and pressure environment, operational modes of

spacecraft and its units, and flight mission.
6.1.4 Monitoring during TBT

The test article shall be operated and monitored throughout the test. Functional tests shall be

conducted before, during, and after the test for flight model. Sufficient and timely measurements shall

be made on the major internal and external units to verify the major units’ thermal design, hardware,

and analyses. The heat flux, temperature, unit’s operation mode and other performance parameters

shall be controlled to meet the requirements of the specified case.

The modification of the thermal analytical model is applicable to all test cases. The modification

parameters shall be within the acceptable range. After modification of the thermal analytical model, the

modification parameters shall be configured to the thermal analytical model to indicate the

temperature of spacecraft flying on orbit.

After the test, a comprehensive analysis shall be made on energy balance in test cases for test error

sources. The absorbed and irradiated heat by the test model shall be compared, whose difference is

generally controlled within ±10 %. Test errors generally are derived from limitations of the heat flux

simulation mode, deviation between the test model and actual spacecraft, measurement accuracy of

heat flux and temperature.
© ISO 2022 – All rights reserved 7
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ISO/FDIS 24412:2022(E)
6.2 Thermal vacuum test
6.2.1 Test description

Spacecraft shall be placed in a thermally controlled vacuum chamber having the capability to expose the

test article at or beyond the minimum and maximum test temperatures.
The following should be considered.
a) Units of spacecraft should be flight products (except qualification test).
b) Some units may be r
...

FINAL
INTERNATIONAL ISO/FDIS
DRAFT
STANDARD 24412
ISO/TC 20/SC 14
Space systems — Thermal vacuum
Secretariat: ANSI
environmental testing
Voting begins on:
2022-11-08
Voting terminates on:
2023-01-03
RECIPIENTS OF THIS DRAFT ARE INVITED TO
SUBMIT, WITH THEIR COMMENTS, NOTIFICATION
OF ANY RELEVANT PATENT RIGHTS OF WHICH
THEY ARE AWARE AND TO PROVIDE SUPPOR TING
DOCUMENTATION.
IN ADDITION TO THEIR EVALUATION AS
Reference number
BEING ACCEPTABLE FOR INDUSTRIAL, TECHNO-
ISO/FDIS 24412:2022(E)
LOGICAL, COMMERCIAL AND USER PURPOSES,
DRAFT INTERNATIONAL STANDARDS MAY ON
OCCASION HAVE TO BE CONSIDERED IN THE
LIGHT OF THEIR POTENTIAL TO BECOME STAN-
DARDS TO WHICH REFERENCE MAY BE MADE IN
NATIONAL REGULATIONS. © ISO 2022
---------------------- Page: 1 ----------------------
ISO/FDIS 24412:2022(E)
FINAL
INTERNATIONAL ISO/FDIS
DRAFT
STANDARD 24412
ISO/TC 20/SC 14
Space systems — Thermal vacuum
Secretariat: ANSI
environmental testing
Voting begins on:
Voting terminates on:
COPYRIGHT PROTECTED DOCUMENT
© ISO 2022

be reproduced or utilized otherwise in any form or by any means, electronic or mechanical, including photocopying, or posting on

the internet or an intranet, without prior written permission. Permission can be requested from either ISO at the address below

or ISO’s member body in the country of the requester.
RECIPIENTS OF THIS DRAFT ARE INVITED TO
ISO copyright office
SUBMIT, WITH THEIR COMMENTS, NOTIFICATION
OF ANY RELEVANT PATENT RIGHTS OF WHICH
CP 401 • Ch. de Blandonnet 8
THEY ARE AWARE AND TO PROVIDE SUPPOR TING
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DOCUMENTATION.
Phone: +41 22 749 01 11
IN ADDITION TO THEIR EVALUATION AS
Reference number
Email: copyright@iso.org
BEING ACCEPTABLE FOR INDUSTRIAL, TECHNO
ISO/FDIS 24412:2022(E)
Website: www.iso.org
LOGICAL, COMMERCIAL AND USER PURPOSES,
DRAFT INTERNATIONAL STANDARDS MAY ON
Published in Switzerland
OCCASION HAVE TO BE CONSIDERED IN THE
LIGHT OF THEIR POTENTIAL TO BECOME STAN
DARDS TO WHICH REFERENCE MAY BE MADE IN
© ISO 2022 – All rights reserved
NATIONAL REGULATIONS. © ISO 2022
---------------------- Page: 2 ----------------------
ISO/FDIS 24412:2022(E)
Contents Page

Foreword ..........................................................................................................................................................................................................................................v

Introduction .............................................................................................................................................................................................................................. vi

1 Scope ................................................................................................................................................................................................................................. 1

2 Normative references ..................................................................................................................................................................................... 1

3 Terms and definitions .................................................................................................................................................................................... 1

4 Symbols and abbreviated terms..........................................................................................................................................................2

5 Test purpose ............................................................................................................................................................................................................. 2

5.1 Thermal balance test ........................................................................................................................................................................ 2

5.2 Thermal vacuum test ........................................................................................................................................................................ 3

5.2.1 General purpose .................................................................................................................................................................. 3

5.2.2 Qualification test ................................................................................................................................................................ 3

5.2.3 Proto-flight test ................................................................................................................................................................... 3

5.2.4 Acceptance test .................................................................................................................................................................... 3

6 Test methods ............................................................................................................................................................................................................ 3

6.1 Thermal balance test ........................................................................................................................................................................ 3

6.1.1 Test description ................................................................................................................................................................... 3

6.1.2 Test conditions ..................................................................................................................................................................... 6

6.1.3 Basic requirements of test facilities .................................................................................................................. 7

6.1.4 Monitoring during TBT ........................................................................................................................................... ...... 7

6.2 Thermal vacuum test ........................................................................................................................................................................ 7

6.2.1 Test description ................................................................................................................................................................... 7

6.2.2 Test conditions .................................................................................................................................................................. 10

6.2.3 Basic requirements for test facilities ............................................................................................................ 13

6.2.4 Monitoring during TVT ............................................................................................................................................. 13

7 Test facility ........................................................................................................................................... ...................................................................13

7.1 Laboratory environment ............................................................................................................................................................ 13

7.2 Laboratory infrastructure ........................................................................................................................................................ 14

7.3 Test system ............................................................................................................................................................................................. 14

7.3.1 Overview ................................................................................................................................................................................ 14

7.3.2 Chamber system .............................................................................................................................................................. 14

7.3.3 Vacuum system ................................................................................................................................................................. 15

7.3.4 Thermal system ...............................................................................................................................................................15

7.3.5 Data acquisition system ............................................................................................................................................ 18

7.3.6 MGSE .......................................................................................................................................................................................... 18

7.3.7 Contamination measurement and control system ............................................................................ 18

8 Test requirements ...........................................................................................................................................................................................19

8.1 Test tolerance and accuracy .................................................................................................................................................... 19

8.2 Test configuration............................................................................................................................................................................. 19

8.3 Temperature and heat flux measurement ................................................................................................................... 20

8.3.1 General .....................................................................................................................................................................................20

8.3.2 Location of temperature monitoring point for test article ........................................................20

8.3.3 Location of temperature monitoring point for test equipment .............................................20

8.4 Heating device selection .............................................................................................................................................................20

8.5 Safety requirements and recommendations ............................................................................................................ 21

9 Test procedure ....................................................................................................................................................................................................21

9.1 Test flow .................................................................................................................................................................................................... 21

9.2 Test procedure ..................................................................................................................................................................................... 21

9.2.1 General ..................................................................................................................................................................................... 21

9.2.2 Before test ............................................................................................................................................................................. 22

9.2.3 Test implementation .................................................................................................................................................... 23

9.2.4 After test .................................................................................................................................................................................23

iii
© ISO 2022 – All rights reserved
---------------------- Page: 3 ----------------------
ISO/FDIS 24412:2022(E)

10 Test interruption and handling ........................................................................................................................................................24

10.1 Interruption ........................................................................................................................................................................................... 24

10.1.1 Test facility malfunction .......................................................................................................................................... 24

10.1.2 Test article malfunction ............................................................................................................................................ 24

10.2 Interruption handling ................................................................................................................................................................... 24

11 Test documentation .......................................................................................................................................................................................24

Annex A (informative) Main characteristic of a solar simulator ........................................................................................25

Annex B (informative) An example of IR heater design flow for absorbed flux simulation

method in TBT .....................................................................................................................................................................................................27

Bibliography .............................................................................................................................................................................................................................30

ISO (the International Organization for Standardization) is a worldwide federation of national standards

bodies (ISO member bodies). The work of preparing International Standards is normally carried out

through ISO technical committees. Each member body interested in a subject for which a technical

committee has been established has the right to be represented on that committee. International

organizations, governmental and nongovernmental, in liaison with ISO, also take part in the work.

ISO collaborates closely with the International Electrotechnical Commission (IEC) on all matters of

electrotechnical standardization.