ISO 17401:2023

2022-12-07
ISO/FDIS 17401:2021(E)
ISO/TC 20/SC 14/WG 2
Secretariat: ANSI
Date: 2023-01-20
Space systems — Spacecraft interface requirements document for
launch vehicle services
Systèmes spatiaux — Document d'exigences d'interface du véhicule spatial vis-à-vis du service de lancement
ICS: 49.140

---------------------- Page: 1 ----------------------
Error! Reference source not found.
FDIS stage
2

---------------------- Page: 2 ----------------------
ISO/FDIS 17401:2021(E)
© ISO 2021 2023
All rights reserved. Unless otherwise specified, or required in the context of its implementation, no 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
EmailE-mail: copyright@iso.org
Website: www.iso.org
Published in Switzerland
iii © ISO 2021 – All rights reserved

---------------------- Page: 3 ----------------------
ISO/FDIS 17401:20222023(E)
Contents Page
Foreword . vii
Introduction . viii
1 Scope . 1
2 Normative references . 1
3 Terms, definitions and abbreviated terms . 1
3.1 Terms and definitions . 1
3.2 Abbreviated terms . 2
4 Spacecraft mission description . 2
4.1 Mission description . 2
4.2 SC description (optional) . 2
5 Mechanical interfaces . 2
5.1 Mechanical configuration . 2
5.2 SC fundamental frequencies . 2
5.3 Usable volume . 3
5.4 Spacecraft (or SC adapter) mechanical interface . 3
5.5 Connectors and microswitches (SC side of the interface) . 3
5.6 Purges and fluid connection interface . 4
5.7 Encapsulated spacecraft access . 4
6 Electrical interfaces . 4
6.1 Umbilical wiring diagram . 4
6.2 Umbilical connectors . 4
6.3 Umbilical wiring links (for each connector pin) . 5
6.4 Electrical commands dedicated to spacecraft . 5
6.4.1 Pyrotechnic commands . 5
6.4.2 Dry loop commands . 6
6.4.3 Electrical commands . 6
6.5 Separation status transmission . 7
6.6 SC in-flight telemetry . 7
6.7 Power supply required from LV . 7
6.8 Earth potential continuity . 7
7 Radio-frequency and electromagnetic interface . 8
7.1 Characteristics of radio-electrical systems . 8
7.2 RF telemetry and command link . 9
7.2.1 SC RF-link definition for ground operations . 9
7.2.2 SC antenna coordinates . 9
7.2.3 RF-link implementation . 9
7.2.4 RF-link budget . 9
7.2.5 Base band signal characteristics . 10
iv
iv © ISO 2021 – All rights reserved
 © ISO 2023 – All rights reserved

---------------------- Page: 4 ----------------------
ISO/FDIS 17401:20222023(E)
8 Spacecraft mission characteristics. 11
8.1 SC input data for mission analyses . 11
8.1.1 Mass and inertia characteristics . 11
8.1.2 Sloshing masses (pendulum-type) . 11
8.1.3 SC mission constraints (when applicable) . 12
8.2 SC orbit parameters (with tolerances) . 12
8.3 Launch window. 13
8.3.1 Launch window constraints (when applicable) . 13
8.3.2 Preferred window . 13
8.4 SC pointing and separation . 13
9 Environment requirements . 13
9.1 General . 13
9.2 Mechanical environment . 13
9.3 Thermal environment . 14
9.4 Static pressure . 14
9.5 Contamination and cleanliness control . 15
9.6 Radio frequency and electromagnetic environment . 15
9.7 Environment monitoring . 15
9.8 Exposure to sun . 15
10 SC Development and test programme . 15
11 Launch range operations: facilities and support requirements . 16
11.1 General logistics requirements . 16
11.1.1 General . 16
11.1.2 SC container and ground support equipment physical envelopes . 16
11.1.3 Material handling equipment . 17
11.1.4 Electrical power for SC and ground station . 17
11.1.5 Umbilical lines and ground lines. 17
11.1.6 Gas and fluid lines . 17
11.1.7 Clean room . 17
11.1.8 Environmental controls for SC and ground station . 18
11.1.9 Clothing (safety and cleanroom) . 18
11.1.10 Area . 18
11.1.11 Storage (non-hazardous items) . 19
11.1.12 SC pre-launch activities calendar . 19
11.1.13 Special technical support equipment . 19
11.1.14 Other . 19
11.2 Specific requirements for solid propellant motor facilities (Y/N, to specify). 20
11.2.1 Solid propellant motor storage . 20
11.2.2 Pyrotechnics storage . 20
© ISO 2023 – All rights reserved v
© ISO 2021 – All rights reserved v

---------------------- Page: 5 ----------------------
ISO/FDIS 17401:20222023(E)
11.3 Specific requirements for X-ray facilities . 20
11.4 Specific requirements for hazardous operations facilities . 20
11.4.1 Gases . 20
11.4.2 Liquid propellant . 21
11.4.3 SC purge requirements . 21
11.4.4 SC fluid requirements . 21
11.5 Payload handling and transport requirements . 21
11.6 Communication requirements . 22
11.7 General range services . 22
11.8 Safety requirements . 22
12 Other requirements . 22
Bibliography . 23

vi
vi © ISO 2021 – All rights reserved
 © ISO 2023 – All rights reserved

---------------------- Page: 6 ----------------------
ISO/FDIS 17401:20222023(E)
Foreword
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).
Field Code Changed
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).
Any trade name used in this document is information given for the convenience of users and does not
constitute an endorsement.
For an explanation of the voluntary nature of standards, the meaning of ISO specific terms and
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.
This second edition cancels and replaces the first edition (ISO 17401:2004), which has been technically
revised.
The main changes compared to the previous edition are as follows:
— upgrade orbit definition parameters
— upgrade SC environment description
— upgrade SC description (interface, thermal aspects, EMC)
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.
© ISO 2023 – All rights reserved vii
© ISO 2021 – All rights reserved vii

---------------------- Page: 7 ----------------------
ISO/FDIS 17401:20222023(E)
Introduction
This document gives guidelines for writing an interface requirements document (IRD) for launch vehicle
(LV) services. The application of this document is intended to facilitate the technical exchanges between
spacecraft (SC) and launch vehicle agencies. By reducing the amount of work necessary for requesting
launch services, this document will minimize spacecraft contractor's and spacecraft manufacturer's costs.
In some cases, drawings are explicitly requested in order to provide comprehensive information. Explicit
international system units are specified for all items. The corresponding scale may be adjusted if not
appropriate.
SC organizations may include additional topics if required. Some sections of the IRD may refer to
specificities that are not applicable to the launch services of interest, in which case they should be ignored.
viii
viii © ISO 2021 – All rights reserved
 © ISO 2023 – All rights reserved

---------------------- Page: 8 ----------------------
FINAL DRAFT INTERNATIONAL STANDARD ISO/FDIS 17401:2022(E)

Space systems — Spacecraft interface requirements document for
launch vehicle services
1 Scope
This document provides spacecraft (SC) organizations with the general format for presenting the
interface requirement document (IRD) for launch vehicle services. The IRD provides a list of the major
technical requirements spacecraft agencies provide to launch vehicle (LV) agencies when submitting an
application for launch services.
The IRD addresses the definition of the SC mission, the mechanical and electrical interfaces, the overall
environment requirements (mechanical, thermal, cleanliness, radio-electrical), the SC development and
test programme and, finally, launch range facilities and support requirements.
This document is applicable to all existing commercial LV and related launch facilities so as to permit SC
contractors to prepare a single interface requirement document for a given SC mission, independently of
the LV contractor to be selected.
The IRD, as defined in this document, includes the basic SC input data needed by LV agencies to prepare
the interface control document defined in the ISO 15863.
2 Normative references
There are no normative references in this document.
3 Terms, definitions and abbreviated terms
3.1 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/
And, if required, terminology databases of national space agencies are used.

3.1.1
usable volume
volume available to the payload within the LV fairing or carrying structure that the static envelope of the
SC may not exceed in order to ensure that there is no physical contact between the SC and the LV in a
dynamic environment
3.1.2
spacecraft adapter (SC adapter)
SC adapter
structure that mates the SC to the LV and includes the separation system for SC/LV separation
Note 1 to entry: The SC adapter is a part of the LV and does not separate with the SC.
© ISO 2021 – All rights reserved 1

---------------------- Page: 9 ----------------------
ISO/FDIS 17401:2023(E)
3.2 Abbreviated terms
EIRP equivalent isotropic radiated power
EMC electromagnetic compatibility
IRD interface requirement document
LV launch vehicle
RF radio frequency
SC spacecraft
Y/N yes/no response
4 Spacecraft mission description
4.1 Mission description
The IRD shall describe the following items:
a) a) purpose of the mission;
b) b) orbital characteristics;
c) c) in orbit view of SC, with drawing
4.2 SC description (optional)
The IRD may describe the following items:
a) a) SC platform
b) b) SC payload
5 Mechanical interfaces
5.1 Mechanical configuration
The IRD shall provide the following information:
a) a) SC mechanical drawing (launch configuration);
b) b) SC coordinate system, with drawing;
c) c) maximum height above interface plane, in metres;
d) d) SC overall dimensions (maximum diameter, maximum height, …), in metres;
e) e) SC/LV interface diameter, in metres. SC/LV interface geometrical definition.
f) f) available volumes of SC, in cubic meters
g) g) SC mass center position – relative to the reference frame which is centered in the adapter plane;
h) h) mean-square deviation of SC mass center position along SC axis
5.2 SC fundamental frequencies
The IRD shall provide the fundamental natural frequencies of SC (specify boundary conditions):
a) a) axial frequencies, in hertz;
b) b) lateral frequencies, in hertz.
2 © ISO 2023 – All rights reserved

---------------------- Page: 10 ----------------------
ISO/FDIS 17401:2023(E)
5.3 Usable volume
The IRD shall provide the following information:
a) a) static envelope, with drawing;
b) b) SC protrusions below interface plane, with dimensioned drawings;
c) c) SC volumetric displacement, in cubic metres;
d) d) SC free air volume, in cubic metres;
e) e) special clearance requirements, with drawing.
5.4 Spacecraft (or SC adapter) mechanical interface
The IRD shall provide the following information:
a) a) mechanical interface, with drawing;
b) b) diameter, in metres;
c) c) attachments at SC interface;
d) d) material;
e) e) Young's modulus, in newtons per square metre;
f) f) coating:
1) 1) surfaces in contact,
2) 2) other surfaces;
g) g) roughness, in micrometers of surfaces in contact;
h) h) flatness/perpendicularity of surfaces in contact;
i) i) stiffness (for clampband mating system):
1) 1) applicable length (height), in meters,
2) 2) section area, in square millimeters,
3) 3) inertia (with respect to centre of gravity of section), in millimeters to the power of 4
4
(mm );
j) j) stiffness (except for clampband mating systems):
1) 1) radial direction, in newtons per metre,
2) 2) tangent direction, in newtons per metre.
NOTE This section of the IRD applies to the lower adapter interface ring for a SC provided adapter.
5.5 Connectors and microswitches (SC side of the interface)
The IRD shall provide the following information:
a) a) manufacturer and part number;
b) b) quantity;
© ISO 2023 – All rights reserved 3

---------------------- Page: 11 ----------------------
ISO/FDIS 17401:2023(E)
c) c) location and mechanical interface, with drawing:
1) 1) angular position, in degrees,
2) 2) radial position, in metres,
3) 3) height from separation plane, in metres;
d) d) push-on and push-off loads, in newtons;
e) e) energy released, in joules;
f) f) keying index.
5.6 Purges and fluid connection interface
The IRD shall provide the following information:
a) a) definition;
b) b) location and mechanical interface, with drawing:
1) 1) angular position, in degrees,
2) 2) radial position, in metres,
3) 3) height from separation plane, in metres.
5.7 Encapsulated spacecraft access
For each access requirement to payload, the IRD shall specify the following items:
a) a) location in SC coordinates, in metres, with drawing:
1) 1) X ,
S
2) 2) YS,
3) 3) Z ;
S
b) b) minimum size of access door, length and height in metres;
c) c) purpose.
NOTE The symbols X , Y , Z are the generic coordinates of any point in SC axes (or in axes parallel to the SC
S S S
axes).
6 Electrical interfaces
6.1 Umbilical wiring diagram
Drawings for SC to LV and SC to ground facilities wiring shall be provided.
6.2 Umbilical connectors
The IRD shall provide the following information:
a) a) number of connectors required;
b) b) LV supplied (Y/N, to specify);
c) c) manufacturer;
4 © ISO 2023 – All rights reserved

---------------------- Page: 12 ----------------------
ISO/FDIS 17401:2023(E)
d) d) connector type, name, designation and part number;
e) e) number of pins needed for user;
f) f) polarizing key type and orientation;
g) g) insert key location, with drawing;
h) h) location, with drawing;
i) i) backshell shielding requirement;
j) j) harness shielding requirement.
6.3 Umbilical wiring links (for each connector pin)
The IRD shall provide the following information:
a) a) pin number;
b) b) function(s);
c) c) wire type;
d) d) twisting and shielding characteristics;
e) e) maximum voltage, in volts;
f) f) maximum voltage at lift-off, in volts;
g) g) maximum current, in amperes;
h) h) maximum current at lift-off, in amperes;
i) i) maximum one way resistance, in ohms;
j) j) maximum voltage drop, in volts;
k) k) line start point;
l) l) line end point;
m) m) maximum voltage at separation (if applicable), in volts;
n) n) maximum current at separation (if applicable), in amperes;
o) o) signal type;
p) p) signal frequency, in hertz.
6.4 Electrical commands dedicated to spacecraft
6.4.1 Pyrotechnic commands
The IRD shall provide the following information:
a) a) number of commands required;
b) b) electrical circuit drawing, with drawing;
c) c) command identification;
© ISO 2023 – All rights reserved 5

---------------------- Page: 13 ----------------------
ISO/FDIS 17401:2023(E)
d) d) number of initiators per command;
e) e) time of command initiation;
f) f) minimum time interval between commands, in seconds;
g) g) pulse width, in seconds;
h) h) voltage, in volts;
i) i) minimum all fire current, in amperes;
j) j) maximum no fire current, in amperes;
k) k) output isolation, in ohms;
l) l) wire gage;
m) m) wire type;
n) n) wire length from LV-SC interface to pyrotechnic devices, in metres;
o) o) circuit connectors to pyrotechnic devices;
p) p) initiator characteristics.
6.4.2 Dry loop commands
The IRD shall provide the following information:
a) a) number of commands required;
b) b) command identification;
c) c) number of redundant commands;
d) d) time of command initiation (on ground or in flight);
e) e) resistance (ON/OFF configurations), in ohms;
f) f) maximum, minimum and nominal output voltage, in volts;
g) g) maximum current, in amperes;
h) h) on-board circuit isolation, in ohms;
i) i) grounding requirements;
j) j) SC circuit configuration, with drawing.
6.4.3 Electrical commands
The IRD shall provide the following information:
a) a) number of commands required;
b) b) command identification
c) c) number of redundant c
...

FINAL
INTERNATIONAL ISO/FDIS
DRAFT
STANDARD 17401
ISO/TC 20/SC 14
Space systems — Spacecraft interface
Secretariat: ANSI
requirements document for launch
Voting begins on:
2023-02-06 vehicle services
Voting terminates on:
Systèmes spatiaux — Document d'exigences d'interface du véhicule
2023-04-03
spatial vis-à-vis du service de lancement
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 17401:2023(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 2023

---------------------- Page: 1 ----------------------
ISO/FDIS 17401:2023(E)
FINAL
INTERNATIONAL ISO/FDIS
DRAFT
STANDARD 17401
ISO/TC 20/SC 14
Space systems — Spacecraft interface
Secretariat: ANSI
requirements document for launch
Voting begins on:
vehicle services
Voting terminates on:
Systèmes spatiaux — Document d'exigences d'interface du véhicule
spatial vis-à-vis du service de lancement
COPYRIGHT PROTECTED DOCUMENT
© ISO 2023
All rights reserved. Unless otherwise specified, or required in the context of its implementation, no 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.
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
CH-1214 Vernier, Geneva
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 17401:2023(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
ii
  © ISO 2023 – All rights reserved
NATIONAL REGULATIONS. © ISO 2023

---------------------- Page: 2 ----------------------
ISO/FDIS 17401:2023(E)
Contents Page
Foreword .v
Introduction . vi
1 Scope . 1
2 Normative references . 1
3 Terms, definitions and abbreviated terms . 1
3.1 Terms and definitions . 1
3.2 Abbreviated terms . 2
4 Spacecraft mission description .2
4.1 Mission description . 2
4.2 SC description (optional) . 2
5 Mechanical interfaces. 2
5.1 Mechanical configuration . 2
5.2 SC fundamental frequencies . 3
5.3 Usable volume. 3
5.4 Spacecraft (or SC adapter) mechanical interface . 3
5.5 Connectors and microswitches (SC side of the interface) . 4
5.6 Purges and fluid connection interface . 4
5.7 Encapsulated spacecraft access . 4
6 Electrical interfaces .4
6.1 Umbilical wiring diagram . 4
6.2 Umbilical connectors . 5
6.3 Umbilical wiring links (for each connector pin) . 5
6.4 Electrical commands dedicated to spacecraft . 6
6.4.1 Pyrotechnic commands . . 6
6.4.2 Dry loop commands . 6
6.4.3 Electrical commands . 7
6.5 Separation status transmission . 7
6.6 SC in-flight telemetry . 7
6.7 Power supply required from LV . 7
6.8 Earth potential continuity . 8
7 Radio-frequency and electromagnetic interface . 8
7.1 Characteristics of radio-electrical systems . 8
7.2 RF telemetry and command link . 9
7.2.1 SC RF-link definition for ground operations . 9
7.2.2 SC antenna coordinates . 9
7.2.3 RF­link implementation . 9
7.2.4 RF­link budget . 9
7.2.5 Base band signal characteristics . 10
8 Spacecraft mission characteristics .11
8.1 SC input data for mission analyses . 11
8.1.1 Mass and inertia characteristics . 11
8.1.2 Sloshing masses (pendulum-type) .12
8.1.3 SC mission constraints (when applicable) .12
8.2 SC orbit parameters (with tolerances) .12
8.3 Launch window .13
8.3.1 Launch window constraints (when applicable) .13
8.3.2 Preferred window .13
8.4 SC pointing and separation . . .13
9 Environment requirements .13
9.1 General .13
9.2 Mechanical environment . 14
iii
© ISO 2023 – All rights reserved

---------------------- Page: 3 ----------------------
ISO/FDIS 17401:2023(E)
9.3 Thermal environment . 14
9.4 Static pressure . 15
9.5 Contamination and cleanliness control . 15
9.6 Radio frequency and electromagnetic environment . 15
9.7 Environment monitoring . 15
9.8 Exposure to sun . 15
10 SC Development and test programme .16
10.1 Mechanical environment qualification tests . 16
10.2 LV/SC compatibility tests . 16
11 Launch range operations: facilities and support requirements .16
11.1 General logistics requirements . 16
11.1.1 General . 16
11.1.2 SC container and ground support equipment physical envelopes . 17
11.1.3 Material handling equipment . . 17
11.1.4 Electrical power for SC and ground station . 17
11.1.5 Umbilical lines and ground lines . 17
11.1.6 Gas and fluid lines . 17
11.1.7 Clean room . 18
11.1.8 Environmental controls for SC and ground station . 18
11.1.9 Clothing (safety and cleanroom) . 18
11.1.10 Area . 19
11.1.11 Storage (non­hazardous items) . 19
11.1.12 SC pre­launch activities calendar . 19
11.1.13 Special technical support equipment . 19
11.1.14 Other . 20
11.2 Specific requirements for solid propellant motor facilities (Y/N, to specify) .20
11.2.1 Solid propellant motor storage . 20
11.2.2 Pyrotechnics storage .20
11.3 Specific requirements for X-ray facilities . 20
11.4 Specific requirements for hazardous operations facilities . 21
11.4.1 Gases. 21
11.4.2 Liquid propellant . 21
11.4.3 SC purge requirements . 21
11.4.4 SC fluid requirements . 21
11.5 Payload handling and transport requirements . 21
11.6 Communication requirements.22
11.7 General range services .22
11.8 Safety requirements .22
12 Other requirements . .23
Bibliography .24
iv
  © ISO 2023 – All rights reserved

---------------------- Page: 4 ----------------------
ISO/FDIS 17401:2023(E)
Foreword
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.
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).
Any trade name used in this document is information given for the convenience of users and does not
constitute an endorsement.
For an explanation of the voluntary nature of standards, the meaning of ISO specific terms and
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.
This second edition cancels and replaces the first edition (ISO 17401:2004), which has been technically
revised.
The main changes compared to the previous edition are as follows:
— upgrade orbit definition parameters
— upgrade SC environment description
— upgrade SC description (interface, thermal aspects, EMC)
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.
v
© ISO 2023 – All rights reserved

---------------------- Page: 5 ----------------------
ISO/FDIS 17401:2023(E)
Introduction
This document gives guidelines for writing an interface requirements document (IRD) for launch
vehicle (LV) services. The application of this document is intended to facilitate the technical exchanges
between spacecraft (SC) and launch vehicle agencies. By reducing the amount of work necessary for
requesting launch services, this document will minimize spacecraft contractor's and spacecraft
manufacturer's costs.
In some cases, drawings are explicitly requested in order to provide comprehensive information.
Explicit international system units are specified for all items. The corresponding scale may be adjusted
if not appropriate.
SC organizations may include additional topics if required. Some sections of the IRD may refer to
specificities that are not applicable to the launch services of interest, in which case they should be
ignored.
vi
  © ISO 2023 – All rights reserved

---------------------- Page: 6 ----------------------
FINAL DRAFT INTERNATIONAL STANDARD ISO/FDIS 17401:2023(E)
Space systems — Spacecraft interface requirements
document for launch vehicle services
1 Scope
This document provides spacecraft (SC) organizations with the general format for presenting the
interface requirement document (IRD) for launch vehicle services. The IRD provides a list of the major
technical requirements spacecraft agencies provide to launch vehicle (LV) agencies when submitting an
application for launch services.
The IRD addresses the definition of the SC mission, the mechanical and electrical interfaces, the overall
environment requirements (mechanical, thermal, cleanliness, radio-electrical), the SC development and
test programme and, finally, launch range facilities and support requirements.
This document is applicable to all existing commercial LV and related launch facilities so as to permit SC
contractors to prepare a single interface requirement document for a given SC mission, independently
of the LV contractor to be selected.
The IRD, as defined in this document, includes the basic SC input data needed by LV agencies to prepare
the interface control document defined in ISO 15863.
2 Normative references
There are no normative references in this document.
3 Terms, definitions and abbreviated terms
3.1 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/o bp
— IEC Electropedia: available at https:// www.electropedia . org/
3.1.1
usable volume
volume available to the payload within the LV fairing or carrying structure that the static envelope of
the SC may not exceed in order to ensure that there is no physical contact between the SC and the LV in
a dynamic environment
3.1.2
spacecraft adapter
SC adapter
structure that mates the SC to the LV and includes the separation system for SC/LV separation
Note 1 to entry: The SC adapter is a part of the LV and does not separate with the SC.
1
© ISO 2023 – All rights reserved

---------------------- Page: 7 ----------------------
ISO/FDIS 17401:2023(E)
3.2 Abbreviated terms
EIRP equivalent isotropic radiated power
EMC electromagnetic compatibility
IRD interface requirement document
LV launch vehicle
RF radio frequency
SC spacecraft
Y/N yes/no response
4 Spacecraft mission description
4.1 Mission description
The IRD shall describe the following items:
a) purpose of the mission;
b) orbital characteristics;
c) in orbit view of SC, with drawing
4.2 SC description (optional)
The IRD may describe the following items:
a) SC platform
b) SC payload
5 Mechanical interfaces
5.1 Mechanical configuration
The IRD shall provide the following information:
a) SC mechanical drawing (launch configuration);
b) SC coordinate system, with drawing;
c) maximum height above interface plane, in metres;
d) SC overall dimensions (maximum diameter, maximum height, …), in metres;
e) SC/LV interface diameter, in metres. SC/LV interface geometrical definition.
f) available volumes of SC, in cubic meters
g) SC mass center position – relative to the reference frame which is centered in the adapter plane;
h) mean-square deviation of SC mass center position along SC axis
2
  © ISO 2023 – All rights reserved

---------------------- Page: 8 ----------------------
ISO/FDIS 17401:2023(E)
5.2 SC fundamental frequencies
The IRD shall provide the fundamental natural frequencies of SC (specify boundary conditions):
a) axial frequencies, in hertz;
b) lateral frequencies, in hertz.
5.3 Usable volume
The IRD shall provide the following information:
a) static envelope, with drawing;
b) SC protrusions below interface plane, with dimensioned drawings;
c) SC volumetric displacement, in cubic metres;
d) SC free air volume, in cubic metres;
e) special clearance requirements, with drawing.
5.4 Spacecraft (or SC adapter) mechanical interface
The IRD shall provide the following information:
a) mechanical interface, with drawing;
b) diameter, in metres;
c) attachments at SC interface;
d) material;
e) Young's modulus, in newtons per square metre;
f) coating:
1) surfaces in contact,
2) other surfaces;
g) roughness, in micrometers of surfaces in contact;
h) flatness/perpendicularity of surfaces in contact;
i) stiffness (for clampband mating system):
1) applicable length (height), in meters,
2) section area, in square millimeters,
4
3) inertia (with respect to centre of gravity of section), in millimeters to the power of 4 (mm );
j) stiffness (except for clampband mating systems):
1) radial direction, in newtons per metre,
2) tangent direction, in newtons per metre.
NOTE This section of the IRD applies to the lower adapter interface ring for a SC provided adapter.
3
© ISO 2023 – All rights reserved

---------------------- Page: 9 ----------------------
ISO/FDIS 17401:2023(E)
5.5 Connectors and microswitches (SC side of the interface)
The IRD shall provide the following information:
a) manufacturer and part number;
b) quantity;
c) location and mechanical interface, with drawing:
1) angular position, in degrees,
2) radial position, in metres,
3) height from separation plane, in metres;
d) push­on and push­off loads, in newtons;
e) energy released, in joules;
f) keying index.
5.6 Purges and fluid connection interface
The IRD shall provide the following information:
a) definition;
b) location and mechanical interface, with drawing:
1) angular position, in degrees,
2) radial position, in metres,
3) height from separation plane, in metres.
5.7 Encapsulated spacecraft access
For each access requirement to payload, the IRD shall specify the following items:
a) location in SC coordinates, in metres, with drawing:
1) X ,
S
2) Y ,
S
3) Z ;
S
b) minimum size of access door, length and height in metres;
c) purpose.
NOTE The symbols X , Y , Z are the generic coordinates of any point in SC axes (or in axes parallel to the SC
S S S
axes).
6 Electrical interfaces
6.1 Umbilical wiring diagram
Drawings for SC to LV and SC to ground facilities wiring shall be provided.
4
  © ISO 2023 – All rights reserved

---------------------- Page: 10 ----------------------
ISO/FDIS 17401:2023(E)
6.2 Umbilical connectors
The IRD shall provide the following information:
a) number of connectors required;
b) LV supplied (Y/N, to specify);
c) manufacturer;
d) connector type, name, designation and part number;
e) number of pins needed for user;
f) polarizing key type and orientation;
g) insert key location, with drawing;
h) location, with drawing;
i) backshell shielding requirement;
j) harness shielding requirement.
6.3 Umbilical wiring links (for each connector pin)
The IRD shall provide the following information:
a) pin number;
b) function(s);
c) wire type;
d) twisting and shielding characteristics;
e) maximum voltage, in volts;
f) maximum voltage at lift-off, in volts;
g) maximum current, in amperes;
h) maximum current at lift-off, in amperes;
i) maximum one way resistance, in ohms;
j) maximum voltage drop, in volts;
k) line start point;
l) line end point;
m) maximum voltage at separation (if applicable), in volts;
n) maximum current at separation (if applicabl
...