ISO 24330:2022

Space systems — Rendezvous and Proximity Operations (RPO) and On Orbit Servicing (OOS) — Programmatic principles and practices

This document establishes guiding principles and best practices at the programmatic level for all participants in the rendezvous and proximity operations (RPO) and on-orbit servicing (OOS) industry. These principles and practices establish the broadest boundaries for behaviour of participants in the RPO/OOS industry and precede more detailed standards. In principle, the document also covers both robotic and HSF missions, but requirements are derived from robotic missions. This document is applicable to a broad array of RPO/OOS industry participants from spacecraft equipment manufacturers, spacecraft operators, service providers, developers of RPO/OOS simulation, planning and safety tools, and insurers. It helps to establish responsible norms of behaviour for RPO and OOS that industry participants are supposed to achieve and to promote throughout the global industry.

Systèmes spatiaux — Opérations de proximité et de rendez-vous et services sur orbite — Principes et pratiques programmatiques

General Information

• Status: Published
• Publication Date: 30-Jun-2022
• 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 3 - Operations and support systems
• Current Stage: 6060 - International Standard published
• Start Date: 01-Jul-2022
• Due Date: 16-Aug-2022
• Completion Date: 01-Jul-2022

Standards Content (Sample)

INTERNATIONAL ISO
STANDARD 24330
First edition
2022-07
Space systems — Rendezvous
and Proximity Operations (RPO)
and On Orbit Servicing (OOS) —
Programmatic principles and
practices
Systèmes spatiaux — Opérations de proximité et de rendez-vous et
services sur orbite — Principes et pratiques programmatiques
Reference number
ISO 24330:2022(E)
© ISO 2022
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ISO 24330:2022(E)
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© ISO 2022

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© ISO 2022 – All rights reserved
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ISO 24330:2022(E)
Contents Page

Foreword ........................................................................................................................................................................................................................................iv

Introduction .................................................................................................................................................................................................................................v

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

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

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

4 Programmatic principles for rendezvous and proximity operations (RPO) and on-

orbit servicing (OOS) missions ............................................................................................................................................................. 3

4.1 Responsible design and operations ..................................................................................................................................... 3

4.1.1 Promote safety and mission success ................................................................................................................ 3

4.1.2 Space debris ............................................................................................................................................................................ 3

4.1.3 Effective communications ......................................................................................................................................... 3

4.1.4 Liability for damage and insurance ................................................................................................................... 3

4.2 Transparent operations .................................................................................................................................................................. 3

4.2.1 General ........................................................................................................................................................................................ 3

4.2.2 Notification to states ...................................................................................................................................................... 4

4.2.3 Communications with entities ............................................................................................................................... 4

4.2.4 Notification protocols .................................................................................................................................................... 4

4.2.5 Lessons learned ................................................................................................................................................................... 4

4.2.6 Notification of re-entry hazard ............................................................................................................................. 4

4.2.7 Registration of orbit ........................................................................................................................................................ 4

5 Programmatic practices for rendezvous and proximity operations and on-orbit

servicing missions .............................................................................................................................................................................................. 4

5.1 Design for mission success .......................................................................................................................................................... 4

5.1.1 General ........................................................................................................................................................................................ 4

5.1.2 Formal review of hardware design.................................................................................................................... 5

5.1.3 Resilient software design and verification ................................................................................................. 5

5.1.4 Concepts of operation .................................................................................................................................................... 5

5.1.5 Approved and proven procedures ...................................................................................................................... 5

5.1.6 Trained and qualified operators........................................................................................................................... 5

5.2 Design servicing operations to minimize the risk and consequences of mishaps ..................... 6

5.2.1 Contractual relationship with client ................................... .............................................................................. 6

5.2.2 Communications discipline ....................................................................................................................................... 6

5.2.3 Trajectory practice ........................................................................................................................................................... 6

5.2.4 Third party notifications ............................................................................................................................................ 6

5.2.5 Collision avoidance practices in proximity ................................................................................................. 6

5.2.6 Anomaly resolution .......................................................................................................................................................... 7

5.2.7 On-orbit checkout .............................................................................................................................................................. 7

5.3 Avoidance of interference ............................................................................................................................................................. 7

5.3.1 General ........................................................................................................................................................................................ 7

5.3.2 Avoiding physical interference .............................................................................................................................. 8

5.3.3 Avoiding electromagnetic interference.......................................................................................................... 8

5.4 Information sharing ........................................................................................................................................................................... 8

5.4.1 General ........................................................................................................................................................................................ 8

5.4.2 Development of anomaly resolution standards ...................................................................................... 8

5.4.3 Sharing of anomaly information .......................................................................................................................... 8

Annex A (informative) Information related to programmatic principles and practices .............................9

Annex B (informative) RPO/OOS mission phases ...............................................................................................................................12

Bibliography .............................................................................................................................................................................................................................19

iii
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ISO 24330:2022(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).

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.

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.
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ISO 24330:2022(E)
Introduction

This document outlines the principles and practices that rendezvous and proximity operations and on-

orbit servicing (RPO/OOS) service providers are expected to follow in order to ensure safe operations

and to encourage a healthy RPO/OOS industry. International law, treaties, and agreements have been

researched for compliance and reference. If additional, more specific requirements are needed for

Human Spaceflight (HSF) these can be provided in the future.

This document is intended to be the highest-level standard for the discipline of RPO/OOS for spacecraft

systems. As such, there are several places in the document where a requirement is stated, but

alternative acceptable methods of verification of compliance exist. Examples include but are not limited

to: notification of authorities (4.2.2); certifications of design or operational procedures (5.1.1, 5.1.2,

5.1.3). Clauses 4 and 5 specify programmatic principles and operational practices respectively. Annex A

contains information related to Clause 4 (A.1) and Clause 5 (A.2). Annex B outlines notional RPO/OOS

mission phases.

Initial drafts were produced by the Consortium for Execution of Rendezvous and Servicing Operations

(CONFERS) team, an international team of 26 initial companies promoting standardization for RPO/

OOS missions to improve safety and promote development of the RPO/OOS industry. Work was

performed over a period of 18 months at six international workshops in the US and Germany. With

this issue, the draft has been handed over to ISO TC 20/SC 14 for vetting and processing with the

normal ISO standardization processes. In the further development within ISO, parallel commercial and

governmental RPO/OOS efforts have contributed to the consensus requirements herein.

CONFERS is an independent, self-sustaining forum created to advocate and promote the spacecraft

servicing industry and encourage responsible commercial RPO/OOS. CONFERS collaborates on

research, development, and publication of voluntary consensus principles, best practices, and technical

and safety standards. CONFERS also engages with national governments and international bodies on

policy and oversight of spacecraft servicing activities.
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INTERNATIONAL STANDARD ISO 24330:2022(E)
Space systems — Rendezvous and Proximity Operations
(RPO) and On Orbit Servicing (OOS) — Programmatic
principles and practices
1 Scope

This document establishes guiding principles and best practices at the programmatic level for all

participants in the rendezvous and proximity operations (RPO) and on-orbit servicing (OOS) industry.

These principles and practices establish the broadest boundaries for behaviour of participants in the

RPO/OOS industry and precede more detailed standards. In principle, the document also covers both

robotic and HSF missions, but requirements are derived from robotic missions.

This document is applicable to a broad array of RPO/OOS industry participants from spacecraft

equipment manufacturers, spacecraft operators, service providers, developers of RPO/OOS simulation,

planning and safety tools, and insurers. It helps to establish responsible norms of behaviour for RPO and

OOS that industry participants are supposed to achieve and to promote throughout the global industry.

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 23312, Space Systems — Detailed space debris mitigation requirements for spacecraft

ISO 24113, Space systems — Space debris mitigation requirements

ISO 27875, Space systems — Re-entry risk management for unmanned spacecraft and launch vehicle

orbital stages
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
capture
act of establishing a connection between two space objects
3.2
client
organization contracting for the service
3.3
proximity operations control volume
control volume
operations zone

volume of space established for non-interference and to assure relative navigation control while the

servicer spacecraft (3.15) and client (3.2) space object are within close proximity

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ISO 24330:2022(E)
3.4
client space object
space object being serviced by the servicer spacecraft (3.15)
Note 1 to entry: It is property of the client (3.2).
3.5
coordinated

active, interactive participation between both servicer spacecraft (3.15) and client space object (3.4)

Note 1 to entry: The antonym is uncoordinated.
3.6
docking

process wherein a servicing spacecraft’s GNC actuators are used to execute a controlled contacting

trajectory to a client space object (3.4) in such a manner as to align and mesh the interface mechanisms

3.7
on-orbit servicing
OOS

on-orbit activities by a servicer spacecraft (3.15) which requires rendezvous (3.12) and/or proximity

Note 1 to entry: This may include servicing operations (3.16).
3.8
passively safe trajectory

trajectory which does not interfere with a convex envelope, volume, zone or any area defined to avoid

contact with sufficient margin of the client space object (3.4) when control is lost

3.9
prepared

status of the servicer (3.14), servicer spacecraft (3.15), client (3.2) and client space object (3.4) having

taken actions to be ready for RPO or OOS
3.10
proximity operations

series of orbital manoeuvres executed to place and maintain a spacecraft in the vicinity of another space

object (artificial or natural bodies) on a relative planned path for a specific time duration to accomplish

mission objectives
3.11
relocation
operation to change the orbit of the client space object (3.4)
Note 1 to entry: See also re-orbit (3.13).
3.12
rendezvous

process wherein two space objects (artificial or natural bodies) are intentionally brought close together

through a series of orbital manoeuvres at a planned time and place
3.13
re-orbit
operation to change the orbit of the client space object (3.4)
Note 1 to entry: See also relocation (3.11).
3.14
servicer
organization that provides on-orbit servicing (3.7) operations by contract
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ISO 24330:2022(E)
3.15
servicer spacecraft
spacecraft performing the servicing operation (3.16)
3.16
servicing operation

action provided by servicer spacecraft (3.15) to the client space object (3.4), including but not limited

to inspection, capture (3.1), docking (3.6), relocation (3.11), refuelling, repair, upgrade, assembly and

release
4 Programmatic principles for rendezvous and proximity operations (RPO) and
on-orbit servicing (OOS) missions
4.1 Responsible design and operations
4.1.1 Promote safety and mission success

In order for the industry to flourish, servicers shall ensure their activities are planned and conducted

to promote safety and mission success, to include other space assets, their activities, the orbital

environment and ground environment.
4.1.2 Space debris

4.1.2.1 Servicer spacecraft manufacturer and servicer shall ensure conformity to ISO 24113.

4.1.2.2 Further, the Servicer shall ensure that both the Servicer spacecraft and the Client Space Object

under the Servicer’s responsibilities avoid generating space debris during servicing operations.

4.1.2.3 Provisions shall be made in service planning and operations for mitigating the adverse

consequences of a close approach, such as a collision that generates space debris.

4.1.2.4 In the case of a mission extension service (e.g. refuelling, relocation/re-orbit or components

replacement), the client shall verify that the client space object meets ISO 24113 requirements

throughout its extended mission lifetime.

NOTE This explicitly makes ISO 24113 applicable to the client space object, even if it was manufactured or

placed into operation prior to the publication of ISO 24113.
4.1.3 Effective communications

During a servicing operation, the servicer and client organizations shall establish and maintain effective

communications in support of safe and successful operations.
4.1.4 Liability for damage and insurance

A servicing operation shall be insured to cover the risk of damage to the activity of third parties.

NOTE The liability for damage can be covered by conventional insurance, financial reserves, alternative

operational support or other means.
4.2 Transparent operations
4.2.1 General

The servicer and client conducting servicing operations shall work within the principle of transparency

to promote safety and trust.
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ISO 24330:2022(E)
4.2.2 Notification to states

It is presupposed that the servicer and client involved in servicing operations notify the proper state

authorities of the intended operations (general nature, timing, locations) and results of servicing

[1]
operations according to relevant law. See Article XI of the OST .
4.2.3 Communications with entities

The servicer and client conducting servicing operations shall take reasonable measures by sufficient

communication and coordination with entities not associated with the RPO/OOS activities that have

safety concerns, due to proximity, about the intentions or interference by the servicing operation to

[1]
support safety and avoid harmful interference. See Article IX of the OST .
4.2.4 Notification protocols

The servicer and client conducting the servicing operations shall develop and implement a protocol that

provides timely public notification of anomalies or mishaps that can have an adverse impact on other

entities or the space environment.
4.2.5 Lessons learned

The servicer and client conducting servicing operations shall look for opportunities to share lessons

learned from operational successes and anomalies while protecting intellectual property and

competition-sensitive information.
4.2.6 Notification of re-entry hazard
4.2.6.1 Assessment of re-entry hazard

If a mission purpose is to capture a client space object and place it into a re-entry trajectory, the

servicer shall assess re-entry risk for all spacecraft and objects which will re-enter as a result of service

operation.
4.2.6.2 Notification of re-entry event

In the case of re-entry, relevant state actors (e.g. civil aviation, communications or maritime authorities)

require the notification of the servicer of anticipated re-entry risk(s). This notification supports

notification to the United Nations Office of Outer Space Affairs registration of objects launched

into outer space. Re-entry shall be in accordance with ISO 24113 and ISO 27875. See Convention on

[2]
Registration of Objects Launched into Outer Space (1976) .
4.2.7 Registration of orbit

It is presupposed that the initial orbit and subsequent significant orbital changes are registered in

accordance with relevant registration regulations.
5 Programmatic practices for rendezvous and proximity operations and on-orbit
servicing missions
5.1 Design for mission success
5.1.1 General

For coordinated RPO and OOS, servicers should develop a state-of-the-art/best practices and holistic

approach to the system design and verification, and design and verification of operations of their

servicing system to enhance safety and mission success.
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ISO 24330:2022(E)

The system design shall consider risk mitigation and operational safety practices across the layers of

control specified in 5.1.2 to 5.1.6.
5.1.2 Formal review of hardware design

Hardware provides essential guidance, navigation and control (including propulsion, attitude control,

etc.) and mechanism capabilities for RPO and OOS. This includes but is not limited to a relative navigation

sensor system, on- and off -board navigation systems, interfaces in terms of sensor support patterns

or docking/capture mechanisms and attitude determination and control subsystems. Modelling,

simulation, component and system-level testing, and documentation of as-built hardware are critical to

providing a reliable and sustainable system.

The systems involved in OOS shall verify hardware design for system and operational safety. (See

ISO 23135 for verification standard requirements).
5.1.3 Resilient software design and verification

Software provides both the ability for varying levels of RPO and OOS automation and autonomy as well

as fault detection and corrective logic. Software designs and functionality should be verified using,

for example, extensive simulation runs to model sensor inputs to the relative navigation algorithms.

Baselining, performance verification, and the ability to update or patch in-flight are key to resilient

software design that shall help ensure confidence in mission execution.

The systems involved in OOS shall have software design verified for system and operational safety.

5.1.4 Concepts of operation

Concepts of operations (CONOPS) define the full set of expected and acceptable RPO and OOS scenarios,

implementing the elements/components of the expected system architectures, and techniques to be

utilized that focus on spaceflight safety. Specific techniques may include passively safe orbits, safety

zones, and keep-out spheres or volumes for RPO and OOS activities. For experimental or first use

activities, a “crawl, walk, run” approach to assessing capability, verifying functionality and performance

while building confidence and experience is an essential prerequisite to implementing in sensitive

environments (e.g. geostationary belt or near crewed spacecraft).

The systems involved in OOS shall verify the concept of operations for system and operational safety

and a hazard assessment analysis. See ISO/IEC/IEEE 29148 for general CONOPS standard requirements.

See ISO 23135 for verification standard requirements.
5.1.5 Approved and proven procedures

Organizationally controlled procedures (i.e. configuration-controlled procedures) along with defined

guidelines, constraints and limitations are the foundation to ensure safety and success in baselining the

plan to achieve RPO and subsequent servicing. The approved procedures should align with the CONOPS

and establish the foundation for the servicer to execute.

Procedures, including operational procedures and instructions as well as flight rules and test and

operational Limits, shall be reviewed and tested for completeness, correctness, and safety.

5.1.6 Trained and qualified operators

Servicer spacecraft and client space object operators are critical to safety and enabling mission success.

An operations team that is trained, experienced, disciplined and rehearsed is a substantial confidence

builder for sustainable and repeatable servicing missions.

Servicer spacecraft and client space object operators shall be trained, experienced and have rehearsed

procedures to detect anomalous navigation and control conditions, system health, and mission

performance, as well as to manually intervene, if necessary, to limit material safety risks and hazards.

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ISO 24330:2022(E)
5.2 Design servicing operations to minimize the risk and consequences of mishaps
5.2.1 Contractual relationship with client
5.2.1.1 General

RPO and OOS operations shall be performed by a servicer for a contracted and cognizant client.

5.2.1.2 Cases with no known owner

For cases where the owner cannot be identified (e.g. space debris objects), perform RPO and

OOS operations in a safe and transparent manner. This may include providing public notice and

communication of intent to States that are possibly the source of the object.
5.2.1.3 Cases with an owner identified after servicing operations begin

If the source is identified during/following the service, the relevant source shall be notified. See

[2]
Convention on Registration of Objects Launched into Outer Space (1976) .
5.2.2 Communications discipline

Sufficient communications discipline shall be employed between the servicer and client to ensure

positive control of both objects during the servicing operation.
5.2.3 Trajectory practice
5.2.3.1 Passively safe trajectories

Except while in or establishing a proximity operations control volume (See B.7), passively safe

trajectories shall be used.
5.2.3.2 With other than client space objects

Close approaches with space objects other than the client space object shall be avoided.

5.2.3.3 Propagation uncertainty

The trajectory propagation to be considered shall include all navigation uncertainties, process noise

and perturbations.
5.2.4 Third party notifications

Servicers and/or clients shall notify and exchange information with affected third parties in advance of

close approaches to support safety of spaceflight (e.g. operator points-of-contact, ephemerides, ability

to manoeuvre, and manoeuvre plans) while respecting owner/operator intellectual property and

proprietary information. See 5.2.1 for situations where no owners can be identified.

NOTE The client can satisfy this requirement by proxy arrangements through the servicer.

5.2.5 Collision avoidance practices in proximity
5.2.5.1 General
To minimize the likelihood of and adverse consequences from interference,
...