ISO 16127:2014

INTERNATIONAL ISO
STANDARD 16127
First edition
2014-02-15
Space systems — Prevention of break-
up of unmanned spacecraft
Systèmes spatiaux — Prévention de l’éclatement des navettes sans
pilote
Reference number
©
ISO 2014
© ISO 2014
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ii © ISO 2014 – All rights reserved

Contents Page
Foreword .iv
Introduction .v
1 Scope . 1
2 Normative references . 1
3 Terms and definitions . 1
4 Implementation . 2
4.1 Design process. 2
4.2 Verification . 2
4.3 Prevention of break-ups until end of life . 3
4.4 Prevention of break-up after end of life. 3
5 Stored energy sources . 3
5.1 Systems storing energy . 3
5.2 Electrical systems . 4
5.3 Propulsion systems . 4
5.4 Pressurized systems . 5
5.5 Other energy sources . 5
Annex A (informative) Procedure for estimating break-up probability. 6
Bibliography . 9
Foreword
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The committee responsible for this document is ISO/TC 20, Aircraft and space vehicles, Subcommittee
SC 14, Space systems and operations.
iv © ISO 2014 – All rights reserved

Introduction
An ever-increasing number of man-made items are orbiting the Earth and bring with them ever-
increasing risk of collisions. This can have implications on the operational requirements of both manned
and unmanned spacecraft.
One potential source of space debris is the break-up of unmanned spacecraft both during and after the
end of their operational lives. This break-up could be due either to external collisions or to internal
factors caused by the existence of stored energy sources onboard the spacecraft. A cloud of debris from
a single spacecraft having broken up poses a significantly greater threat of collision than the original
spacecraft.
This International Standard defines the requirements to reduce the probability of a spacecraft breaking
up, both during and after its operational life. It also defines the requirements for passivation of the
spacecraft, which is the process by which all sources of stored energy are removed.
INTERNATIONAL STANDARD ISO 16127:2014(E)
Space systems — Prevention of break-up of unmanned
spacecraft
1 Scope
This International Standard defines the requirements to reduce the risk of in-orbit break-up of
unmanned spacecraft, both during and after their operational lives. The aim would be met by reducing
the possibility of a break-up caused by an unplanned internally caused event and by depleting to a safe
level all the sources of stored energy at the end of a spacecraft’s life. This International Standard is
designed for use in planning, verifying, and implementing the prevention of break-up of a spacecraft.
This International Standard applies only to unmanned spacecraft operating in Earth orbit. It does not
apply to manned space vehicles or launch vehicle orbital stages. Additionally, it does not cover nuclear
power sources within spacecraft.
This International Standard is not applicable to fragmentation as a result of external particle impacts
(which includes fragmentations triggered by external particle impact but powered by internal energy
sources).
2 Normative references
The following documents, in whole or in part, are normatively referenced in this document and are
indispensable for its application. For dated references, only the edition cited applies. For undated
references, the latest edition of the referenced document (including any amendments) applies.
ISO 14623, Space systems - Pressure vessels and pressurized structures — Design and operation
ISO 24638, Space systems — Pressure components and pressure system integration
ISO 24113:2011, Space systems — Space debris mitigation requirements
3 Terms and definitions
For the purposes of this document, the terms and definitions given in ISO 24113:2011 and the following
apply.
3.1
acquiring organization
organization that plans and manages the development and acquisition contracts for the space system
Note 1 to entry: The responsibilities of the acquiring organization include the engineering and technical aspects
of the space system’s design and operations.
3.2
break-up probability
combined probability of the occurrence of all anomalous events, excluding meteoroid or debris impact,
that leads to the generation of orbital debris
3.3
passivation
elimination of all stored energy on a space system to reduce the chance of break-up
Note 1 to entry: Typical passivation measures include venting or burning excess propellant, discharging batteries,
and relieving pressure vessels.
4 Implementation
4.1 Design process
In accordance with ISO 24113, the spacecraft shall be designed to prevent break-ups while in orbit, both
before end of life and after the end of life.
The spacecraft shall be designed to prevent break-ups while in orbit until its end of life, in accordance
with probability levels defined in ISO 24113:2011, 6.2.2.1, and to enable passivation before its end of life.
Calculations shall be performed to determine the accidental break-up probability. Annex A reports an
example of an acceptable detailed evaluation approach.
The design process and the definition of the operations (including operational and disposal phases)
shall prevent potential failures which could occur during operational life, but also after the end of life.
All onboard sources of stored energy, such as residual propellants, batteries, high-pressure vessels,
self-destructive devices, flywheels, and momentum wheels, shall be depleted or safed and permanently
deactivated once they are no longer required for the mission operation.
The spacecraft provider shall produce a break-up prevention plan. This plan shall be reviewed and
updated as part of the normal spacecraft design review process. The acquiring organization/operator
shall be involved with these design reviews and approve the proposed solutions. All management shall
be done in accordance with ISO 24113.
When producing the break-up prevention plan, a system level risk assessment approach shall be used.
Each source of stored energy shall be considered: what potential failure modes could result in an in-
orbit break-up of the spacecraft (including post-disposal phase) and what can be performed to mitigate
the risk in the design, operational, and disposal phases of the mission as well as after the end of life.
Annex A provides further details regarding producing the plan.
The plan shall be developed by considering each item containing stored energy. The design shall take
into account the following influences:
— the environmental extremes expected to be encountered during the operational life and following
passivation, but excluding re-entry phase;
— mechanical degradation during the mission and following passivation;
— chemical decomposition;
— the effect of potential failure modes of the spacecraft during the mission, and what effect they would
have on the ability to passivate the spacecraft.
The robustness of the design shall be confirmed during the design review process, to ensure that
adequate reliability and quality control has been performed to inhibit any failure that could lead to a
break-up event with a probability as defined in ISO 24113.
4.2 Verification
Throughout the ground phases of a mission, i.e. design, manufacture, AIT (Assembly, Integration,
and Test), and launch, the implementation of the break-up prevention plan shall be reviewed. All the
hardware and software designed specifically for the purpose of break-up prevention should be verified
either by test, demonstration, analysis, or simulation (in that order of preference).
2 © ISO 2014 – All rights reserved

4.3 Prevention of break-ups until end of life
4.3.1 Monitoring during operations
For the operations of the spacecraft, procedures should be defined to allow monitoring of the relevant
...