ISO 15388:2022

Space systems — Contamination and cleanliness control

This document establishes general requirements for contamination and cleanliness control that are applicable, at all tiers of supply, to the development of space systems, including ground processing facilities, ground support equipment, launch vehicles, spacecraft, payloads, and ground processing and on-orbit operations. It also provides guidelines for the establishment of a contamination and cleanliness control programme.

Systèmes spatiaux — Contrôle de la contamination et de la propreté

General Information

• Status: Published
• Publication Date: 24-Oct-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 6 - Materials and processes
• Current Stage: 6060 - International Standard published
• Start Date: 25-Oct-2022
• Due Date: 24-Apr-2022
• Completion Date: 25-Oct-2022

Relations

• Revises: ISO 15388:2012 - Space systems — Contamination and cleanliness control
• Effective Date: 23-Apr-2020

Standards Content (Sample)

INTERNATIONAL ISO
STANDARD 15388
Third edition
2022-10
Space systems — Contamination and
cleanliness control
Systèmes spatiaux — Contrôle de la contamination et de la propreté
Reference number
ISO 15388:2022(E)
© ISO 2022
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ISO 15388:2022(E)
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© ISO 2022

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ISO 15388:2022(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 .............................................................................................................................................................................. 7

4 Management ............................................................................................................................................................................................................. 8

4.1 Organization ............................................................................................................................................................................................. 8

4.2 Cleanliness requirement specification (CRS) ............................................................................................................. 8

4.3 Contamination and cleanliness control plan (CCCP) ............................................................................................ 8

4.4 Interface control document (ICD) .......................................................................................................................................... 9

4.5 Project reviews ...................................................................................................................................................................................... 9

5 Design activities ................................................................................................................................................................................................... 9

5.1 Identification of sensitive hardware ................................................................................................................................... 9

5.2 Nature of contaminants, their profile and their effects ..................................................................................... 9

5.2.1 General ........................................................................................................................................................................................ 9

5.2.2 Typical contaminants ..................................................................................................................................................... 9

5.2.3 Contamination profile ................................................................................................................................................ 10

5.2.4 Effects of contamination on performance ................................................................................................ 10

5.3 Contamination prediction ......................................................................................................................................................... 10

5.4 Contamination budget .................................................................................................................................................................. 10

5.5 Cleanliness-oriented design .................................................................................................................................................... 10

5.6 Selection of materials and processes ............................................................................................................................... 11

5.6.1 General ..................................................................................................................................................................................... 11

5.6.2 Outgassing............................................................................................................................................................................. 11

5.6.3 Absorbed water vapour............................................................................................................................................. 11

5.6.4 Offgassing ..............................................................................................................................................................................12

5.6.5 Quality control ..................................................................................................................................................................12

6 Biocontamination ............................................................................................................................................................................................12

6.1 General ........................................................................................................................................................................................................12

6.2 Contamination of hardware by microorganisms .................................................................................................12

6.3 Sterile hardware ................................................................................................................................................................................12

6.4 Habitable space systems ............................................................................................................................................................. 13

6.4.1 Habitable spacecraft .................................................................................................................................................... 13

6.4.2 Offgassing ..............................................................................................................................................................................13

6.5 Planetary protection ......................................................................................................................................................................13

6.6 Sample protection.............................................................................................................................................................................13

7 Contamination and cleanliness control for ground operations .....................................................................13

7.1 Training of personnel.....................................................................................................................................................................13

7.2 Cleanroom selection and cleanliness control........................................................................................................... 14

7.2.1 General ..................................................................................................................................................................................... 14

7.2.2 Failure of facilities.......................................................................................................................................................... 14

7.2.3 Facility operating procedures ............................................................................................................................. 14

7.2.4 Additional information .............................................................................................................................................. 14

7.3 Cleanroom garments ...................................................................................................................................................................... 15

7.3.1 General .....................................................................................................................................................................................15

7.3.2 Considerations for garment selection .......................................................................................................... 15

7.3.3 Additional information ..............................................................................................................................................15

7.4 Ground support equipment (GSE) ...................................................................................................................................... 15

7.5 Monitoring cleanliness of flight hardware and its near surroundings .............................................15

7.6 Packaging, storage and transport ...................................................................................................................................... 16

iii
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ISO 15388:2022(E)

7.6.1 Packaging ............................................................................................................................................................................... 16

7.6.2 Storage ...................................................................................................................................................................................... 16

7.6.3 Transport ............................................................................................................................................................................... 16

7.7 Cleaning of flight hardware ..................................................................................................................................................... 16

7.7.1 General ..................................................................................................................................................................................... 16

7.7.2 Cleaning procedures .................................................................................................................................................... 16

7.7.3 Bakeout .................................................................................................................................................................................... 16

7.7.4 Contaminant source containment ................................................................................................................... 17

7.7.5 Purging ..................................................................................................................................................................................... 17

Annex A (informative) Material properties — Electronic databases ............................................................................18

Annex B (informative) Contamination analysis ...................................................................................................................................19

Annex C (informative) Factors of combined uncertainty ...........................................................................................................30

Bibliography .............................................................................................................................................................................................................................31

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ISO 15388:2022(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.

This third edition cancels and replaces the second edition (ISO 15388:2012), which has been technically

revised.
The main changes are as follows:

— Annex B, which details guidelines for contamination analysis procedures, is added;

— Annex C, which indicates factors of combined uncertainty, is added;

— the latest international and national documents for planetary protection are referenced in 6.5.

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 15388:2022(E)
Introduction

This document addresses the preferred programme elements recommended for contamination and

cleanliness control of space systems. This document is written in general terms as a baseline for

developing and implementing the control programme. It can be cited as a baseline within a statement

of work and/or used for assuring proposal precision and contractor performance. The users are

responsible for integrating the elements of this document appropriately to their programme needs.

The purpose of contamination and cleanliness control is to prevent the degradation of the performance

of space systems due to particulate and molecular contamination (including biocontamination), and to

ensure that the mission objectives are achieved.
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INTERNATIONAL STANDARD ISO 15388:2022(E)
Space systems — Contamination and cleanliness control
1 Scope

This document establishes general requirements for contamination and cleanliness control that are

applicable, at all tiers of supply, to the development of space systems, including ground processing

facilities, ground support equipment, launch vehicles, spacecraft, payloads, and ground processing and

on-orbit operations. It also provides guidelines for the establishment of a contamination and cleanliness

control programme.
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 14624-3, Space systems — Safety and compatibility of materials — Part 3: Determination of offgassed

products from materials and assembled articles

ISO 14644-1, Cleanrooms and associated controlled environments — Part 1: Classification of air cleanliness

by particle concentration

ISO 14698-1, Cleanrooms and associated controlled environments — Biocontamination control — Part 1:

General principles and methods

ISO 14698-2, Cleanrooms and associated controlled environments — Biocontamination control — Part 2:

Evaluation and interpretation of biocontamination data

ISO 14952-2, Space systems — Surface cleanliness of fluid systems — Part 2: Cleanliness levels

ISO 14952-3, Space systems — Surface cleanliness of fluid systems — Part 3: Analytical procedures for the

determination of nonvolatile residues and particulate contamination

ASTM E595, Standard Test Method for Total Mass Loss and Collected Volatile Condensable Materials from

Outgassing in a Vacuum Environment

ECSS-Q-ST-70-02C, Space product assurance — Thermal vacuum outgassing test for the screening of space

materials
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/
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ISO 15388:2022(E)
3.1.1
bakeout

activity of increasing the temperature of hardware to accelerate its outgassing (3.1.28) rates with the

intent of reducing the content of molecular contaminants (3.1.11) within the hardware

Note 1 to entry: Bakeout is usually performed in a vacuum environment but may be done in a controlled

atmosphere.
3.1.2
bioaerosol

dispersed biological agents [e.g. viable particles (3.1.29), allergens, toxins or biologically active

compounds of microbial origin] in a gaseous environment
3.1.3
biocontamination

contamination of materials, devices, individuals, surfaces, liquids, gases or air with viable particles

(3.1.29)
3.1.4
clean bench

table or bench-top working surface where a filtered airflow is concentrated across the bench top

Note 1 to entry: These bench tops have an established classification of maximum allowable airborne contaminants

(3.1.11).
3.1.5
cleanliness level

established maximum allowable amount of contamination in a given area or volume, or on a component

Note 1 to entry: The term may also apply to the predicted or measured extent of contamination.

3.1.6
cleanliness requirement specification
CRS

document that defines and identifies the spacecraft items and the environmental areas which are

sensitive to contamination, the acceptable contamination levels at beginning and end of life and the

applicable contamination environment
3.1.7
cleanroom

room within which the number concentration of airborne particles (3.1.29) is controlled and classified,

and which is designed, constructed and operated in a manner to control the introduction, generation

and retention of particles inside the room

Note 1 to entry: The class of airborne particle concentration (3.1.30 and 3.1.31) is specified.

Note 2 to entry: Levels of other cleanliness attributes such as chemical, viable or nanoscale concentrations in the

air, and also surface cleanliness (3.1.39) in terms of particle, nanoscale, chemical and viable concentrations might

also be specified and controlled.

Note 3 to entry: Other relevant physical parameters might also be controlled as required, e.g. temperature,

humidity, pressure, vibration and electrostatic.
[SOURCE: ISO 14644-1:2015, 3.1.1]
3.1.8
cleanroom garment

clothing designed, manufactured and worn specifically to prevent contamination of hardware by

personnel working in the cleanroom (3.1.7)

Note 1 to entry: Cleanroom garments include all items worn by personnel, such as coveralls, frocks, gloves, boots,

finger cots and beard covers.
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ISO 15388:2022(E)
3.1.9
clean zone

defined space within which the number concentration of airborne particles (3.1.29) is controlled and

classified, and which is constructed and operated in a manner to control the introduction, generation

and retention of contaminants (3.1.11) inside the space

Note 1 to entry: The class of airborne particle concentration (3.1.30 and 3.1.31) is specified.

Note 2 to entry: Levels of other cleanliness attributes such as chemical, viable or nanoscale concentrations in the

air, and also surface cleanliness (3.1.39) in terms of particle, nanoscale, chemical and viable concentrations might

also be specified and controlled.

Note 3 to entry: A clean zone(s) can be a defined space within a cleanroom (3.1.7) or might be achieved by a

separative device. Such a device can be located inside or outside a cleanroom.

Note 4 to entry: Other relevant physical parameters might also be controlled as required, e.g. temperature,

humidity, pressure, vibration and electrostatic.
[SOURCE: ISO 14644-1:2015, 3.1.2]
3.1.10
collected volatile condensable material
CVCM

mass that outgasses from a material and subsequently condenses on a collector, expressed as a

percentage of the initial specimen mass
3.1.11
contaminant

unwanted molecular or particulate matter that can affect or degrade the relevant performance or

lifetime of the hardware to which it is attached
3.1.12
contamination

introduction of any undesirable molecular or particulate matter (including microbiological matter) into

an item or into the environment of interest
[SOURCE: ISO 10795:2019, 3.62]
3.1.13
contamination and cleanliness control programme

organized effort to establish and achieve acceptable cleanliness and contamination levels during all

phases of the space system project
3.1.14
contamination and cleanliness control plan
CCCP

document that describes how to implement a contamination and cleanliness control programme (3.1.13),

as either an independent document or a part of the consolidated project plan
3.1.15
contamination budget

allowable levels of contamination of hardware at each phase of ground and flight operations

3.1.16
contamination profile
contamination-related conditions in each phase of ground and flight operations

Note 1 to entry: Conditions include airborne particulate cleanliness classes, pressure, humidity, temperature,

number of personnel engaged in operations, cleaning activities, outlines of facilities and so on.

Note 2 to entry: The contamination profile is part of the contamination and cleanliness control plan (CCCP) (3.1.14).

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ISO 15388:2022(E)
3.1.17
cross-contamination
transfer of contaminants (3.1.11) from one surface or component to another

Note 1 to entry: Transfer can occur by migration along a surface, by physical contact, airborne as an aerosol, or as

a gas or molecular matter.
3.1.18
debris

solid objects with their largest dimension greater than approximately 1 mm (1 000 μm) in size

3.1.19
electrostatic discharge
ESD

electrical breakdown of dielectric or gas or vacuum gaps, and also of surface interface of dissimilar

materials, caused by differential charging of parts of dielectric materials and their interfaces

[SOURCE: ISO 11221:2011, 2.10, modified — The abbreviated term "ESD" has been added.]

3.1.20
generally clean

free from manufacturing residue, dirt, oil, grease, processing debris (3.1.18), or other extraneous

contamination based on visual examination

Note 1 to entry: This level does not apply to hardware that is sensitive to contamination.

[SOURCE: ISO 14952-1:2003, 2.12, modified — The abbreviated term "GC" has been removed.]

3.1.21
ground support equipment
GSE

non-flight systems, equipment or devices necessary to support the operations of transporting,

receiving, handling, assembly, inspection, test, checkout, servicing, launch and recovery of a space

system at launch, landing or retrieval sites
[SOURCE: ISO 14625:2007, 3.1.5]
3.1.22
interface control document
ICD

specification that describes the characteristics that must be controlled at the boundaries between

systems, subsystems and other elements
3.1.23
microorganism
microscopical individual constituted to carry out life functions

Note 1 to entry: Microorganisms include organisms such as bacteria, protozoa, yeasts, moulds, fungi, algae and

organisms that depend upon other life forms for reproduction such as viruses and parasites.

Note 2 to entry: Multicellular organisms and agglomerations of microorganisms may be visible to the unaided

eye.
3.1.24
molecular contamination

contamination due to deposition of molecules on surfaces or their presence in gases or liquids

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ISO 15388:2022(E)
3.1.25
at-rest

condition where the cleanroom (3.1.7) or clean zone (3.1.9) is complete with equipment installed and

operating in a manner agreed upon, but with no personnel present
[SOURCE: ISO 14644-1:2015, 3.3.2]
3.1.26
operational

agreed condition where the cleanroom (3.1.7) or clean zone (3.1.9) is functioning in the specified

manner, with equipment operating and with the specified number of personnel present

[SOURCE: ISO 14644-1:2015, 3.3.3]
3.1.27
offgassing
evolution of gaseous products from a liquid or solid material into an atmosphere

Note 1 to entry: This is for the application in habitable volume considering medical impact on human health.

3.1.28
outgassing
evolution of gaseous species from a material, usually in a vacuum
3.1.29
particle
unit of solid or liquid matter with observable size
[SOURCE: ISO 14952-1:2003, 2.20]
3.1.30
particle concentration
〈on surface〉 number of particles (3.1.29) per unit area
3.1.31
particle concentration
〈by volume〉 number of particles (3.1.29) per unit volume of fluid
3.1.32
responsible organization

organization that is responsible for the contamination and cleanliness control programme (3.1.13) and

which is provided with the authority and resources needed to carry out the programme

3.1.33
recovered mass loss
RML

ratio of the total mass loss (3.1.40) of the specimen without the sorbed water to the initial mass:

w = w − w
RML TML WVR
where
w is the recovered mass loss, in per cent;
RML
w is the ratio of the total mass loss to the initial mass, in per cent;
TML

w is the ratio of the water vapour regained (3.1.42) to the initial mass, in per cent.

WVR
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ISO 15388:2022(E)

Note 1 to entry: The quantity RML is introduced because water is not a critical contaminant (3.1.11) for some

space systems (see 5.6.3). In most cases, the value of WVR is similar to that of the mass of outgassed water.

However, WVR is not exactly the same as the water mass effused from the specimen. Therefore, RML is not equal

to the real value of the mass loss other than water.
3.1.34
sensitive hardware
hardware that can be degraded by contamination
3.1.35
significant surface

surface of an item or product that is required to meet established cleanliness level (3.1.5) requirements

3.1.36
spacecraft charging

increase in electrostatic potential on spacecraft surfaces resulting from low-energy electron flux

impinging on the surface
3.1.37
sterility
absence of viable microorganisms (3.1.23)

Note 1 to entry: Inactivated microbes can still represent an important form of biocontamination (3.1.3).

3.1.38
supplier
provider
organization that provides a product or a service
EXAMPLE Producer, distributor, retailer or vendor of a product or a service.
Note 1 to entry: A provider can be internal or external to the organization.

Note 2 to entry: In a contractual situation, a provider is sometimes called “contractor”.

[SOURCE: ISO 9000:2015, 3.2.5, modified —"provider" has been changed to an admitted term.]

3.1.39
surface cleanliness
level of contamination on a significant surface (3.1.35)
3.1.40
total mass lo
...