ISO 21980:2020

INTERNATIONAL ISO
STANDARD 21980
First edition
2020-01
Space systems — Evaluation of
radiation effects on Commercial-Off-
The-Shelf (COTS) parts for use on low-
orbit satellite
Systèmes spatiaux — Évaluation des effets des radiations sur les
parties commerciales sur étagère (COTS) destinées aux satellites à
orbite basse
Reference number
©
ISO 2020
© ISO 2020
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ii © ISO 2020 – All rights reserved

Contents Page
Foreword .iv
Introduction .v
1 Scope . 1
2 Normative references . 1
3 Terms and definitions . 1
4 Abbreviated terms . 3
5 Radiation resistance design . 4
5.1 Overview . 4
5.2 Basic idea of using COTS parts . 5
5.2.1 Concept of parts selection. 5
5.2.2 COTS parts evaluation . 5
5.2.3 Concept of evaluation method . 5
5.2.4 Concept of application of COTS parts/consumer technology . 5
5.3 Space radiation environment prediction. 5
5.3.1 Space environment . 5
5.3.2 Space radiation environment model . 6
5.3.3 Various parameters . 6
5.3.4 Environmental conditions necessary for evaluation . 6
6 Radiation tolerance test . 7
6.1 Types of irradiation test . 7
6.1.1 Cobalt 60 (gamma ray) irradiation test . 7
6.1.2 Proton beam irradiation test . 7
6.1.3 Heavy ion test . 7
6.2 Alternative irradiation test — Laser pulse test. 7
6.3 Test procedure . 7
6.3.1 Total dose test . 7
6.3.2 Single event test . 7
6.3.3 Displacement damage test . 7
6.3.4 Laser pulse test for SEE test . 7
Annex A (informative) Radiation resistance design procedure . 8
Annex B (informative) Total dose prediction method .13
Annex C (informative) Radiation guidelines for total dose using contour maps .19
Annex D (informative) Comparative example between model prediction and measured values .23
Annex E (informative) Radiation deterioration of electronic components .25
Annex F (informative) Overview of single event effect .27
Annex G (informative) Measures for single events of electronic components .29
Annex H (informative) Measures for single events of devices .31
Annex I (informative) Prediction method of displacement damage .33
Annex J (informative) Resistance for displacement damage of each device .35
Annex K (informative) Displacement damage test guideline for semiconductor device .38
Annex L (informative) Laser pulse test method .44
Bibliography .46
Foreword
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This document was prepared by Technical Committee ISO/TC 20, Aircraft and space vehicles,
Subcommittee SC 14, Space systems and operations.
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iv © ISO 2020 – All rights reserved

Introduction
This document describes methods of evaluating the radiation effects on COTS (Commercial-Off-The-
Shelf) parts used in low Earth orbit (LEO) satellites. Many small (<180 kg) and nano/microsatellites
(1 kg to 50 kg) are launched to LEO altitudes where space radiation exists but is less than at higher
altitudes. As a result, the designers and manufacturers of such satellites are using COTS semiconductor
devices for their satellite components and boards. New industries taking advantage of nano/
microsatellite and CubeSat [1,33 kg × (1U-3U)] satellite capabilities now include IT ventures, mobile
phones, and internet industries along with universities and research institutions.
Satellite manufacturers who prioritize investment efficiency also aim to extend mission lifetimes (up
to three, five and ten years) longer than one-year missions that were common for educational and
technical demonstrations using nano/microsatellites.
Even with relatively lower space radiation conditions in LEO compared to higher orbits, a longer mission
life in LEO poses critical radiation environment constraints for COTS devices onboard small and nano/
microsatellites as well as CubeSats.
While there are methods of evaluating the radiation resistance of space parts, there are limited methods
for evaluating COTS parts used for LEO satellites and these are often based on legacy parts usage.
This document provides guidance for evaluating radiation tolerance of COTS parts that can help
increase confidence levels of longer-term mission lifetimes.
INTERNATIONAL STANDARD ISO 21980:2020(E)
Space systems — Evaluation of radiation effects on
Commercial-Off-The-Shelf (COTS) parts for use on low-orbit
satellite
1 Scope
This document outlines the evaluation methods for environmental tests that can be conducted on COTS
(Commercial-Off-The-Shelf) spacecraft parts intended for use on LEO satellites. The radiation effects
considered consist of total dosage, single event, and displacement damage. In addition, this document
describes tests that are useful for satellites operating in LEO.
2 Normative references
There are no normative references in this document.
3 Terms and definitions
For the purposes of this document, the following terms and definitions apply.
ISO and IEC maintain terminological databases for use in standardization at the following addresses:
— ISO Online browsing platform: available at https:// www .iso .org/ obp
— IEC Electropedia: available at http:// www .electropedia .org/
3.1
galactic cosmic rays
GCR
high-energy-charged particle fluxes (3.2) penetrating the heliosphere from local interstellar space
Note 1 to entry: Galactic cosmic rays are composed primarily of high-energy protons and atomic nuclei. Upon
impact with the Earth's atmosphere, cosmic rays can produce showers of secondary particles that sometimes
reach the Earth’s surface. There is evidence that a significant fraction of primary cosmic rays originate from
stellar supernova explosions and perhaps from active galactic nuclei.
[SOURCE: ISO 15390:2004, 2.1, modified — Note 1 to entry has been added.]
3.2
flux
number of particles passing through a specific unit area per unit time
[SOURCE: ISO 12208:2015, 2.3]
3.3
fluence
time-integrated flux (3.2)
Note 1 to entry: Fluence is measured as the flux per unit area per unit time. This is used to express the
environment during the operational lifetime of a spacecraft or space instrument. The integrated particles fluence
−2 −2 −1
unit is expressed as particles m . The energy integral fluence unit is expressed as particles m MeV . When the
−1
directional fluence is included, add per steradian ( sr ).
[SOURCE: ISO 12208:2015, 2.4, modified — Note 1 to entry has been added.]
3.4
absorbed dose
...