ISO 21494-2019 PDF

Full title and description

ISO 21494:2019 — Space systems — Magnetic testing. This international standard defines methods and requirements for magnetic testing of space hardware, covering magnetic field tests, magnetic moment measurements, magnetization and demagnetization procedures, and magnetic compensation techniques applicable at spacecraft, subsystem and unit levels.

Abstract

ISO 21494:2019 provides standardized procedures and guidance to measure, evaluate and control the magnetic properties of space equipment. It supports verification of magnetic cleanliness and quantification of remnant, stray and induced magnetic fields and moments in both controlled (zero-field or coil-generated) and geomagnetic test environments. Informative annexes include procedural details and calculation formulas to support test execution and reporting.

General information

• Status: Published.
• Publication date: 21 February 2019.
• Publisher: International Organization for Standardization (ISO).
• ICS / categories: 49.140 — Space systems and operations.
• Edition / version: First edition (2019).
• Number of pages: 27.

Scope

Specifies magnetic test methods for spacecraft, subsystems and units to verify compliance with magnetic cleanliness and magnetic-moment budgets. The standard addresses tests in zero-magnetic-field facilities (coil systems) and procedures for testing in the natural geomagnetic field, and it covers test-room environment requirements, test sequencing (initial measurements, magnetization, demagnetization, compensation and final verification) and test-report content. It is intended to be applied during verification and acceptance activities for missions where magnetic disturbance or magnetic contamination would affect attitude control or magnetically sensitive payloads.

Key topics and requirements

• Magnetic field test methods: measurement and evaluation of remnant and stray fields at specified locations and on spherical distributions around the equipment under test (EUT).
• Magnetic moment test methods: dipole, near-field and multiple-dipole modelling approaches for determining remnant, stray and induced magnetic moments.
• Magnetization and demagnetization procedures: controlled magnetizing/demagnetizing waveforms and facility requirements to remove or characterize unwanted magnetization.
• Magnetic compensation methods: techniques to mitigate spacecraft magnetic signature (compensation magnets, layout and design controls) and verification after compensation.
• Test facilities and instrumentation: requirements for main coil systems (zero-field and controllable fields), turntables, fixtures and calibrated magnetometers/teslameters.
• Environmental and cleanliness controls: test-room environmental requirements and reference to cleanroom classification (ISO 14644-1) where relevant.
• Reporting and documentation: required test sequence, data, uncertainty treatment and content of the test report.

Typical use and users

Used by spacecraft manufacturers, system and payload engineers, test laboratories, magnetic‑cleanliness engineers and mission verification teams to plan and perform magnetic verification, to qualify equipment and to ensure mission success where magnetic interference or disturbance torque could degrade performance (for example attitude control or magnetometer science instruments). Also used by national and commercial test facilities that provide coil‑based zero-field testing or geomagnetic-field verification services.

Related standards

Normative references and related guidance include ISO 14644-1 (cleanroom classification) which is cited in the standard, and other space-sector documents and handbooks addressing magnetic-cleanliness design and test practice (e.g., emerging ISO technical reports on magnetic cleanliness design and ECSS/agency guidance on magnetic cleanliness and space test centre practices). Users commonly apply ISO 21494 in combination with project-specific magnetic cleanliness requirements and agency/ECSS test standards.

Keywords

magnetic testing; magnetic cleanliness; spacecraft; magnetic field test; magnetic moment; magnetization; demagnetization; magnetic compensation; test facility; Helmholtz coils; geomagnetic field; equipment under test (EUT).

FAQ

Q: What is this standard?

A: ISO 21494:2019 is an international standard that specifies magnetic test methods and guidance for space systems to measure and control magnetic fields and magnetic moments of spacecraft, subsystems and units.

Q: What does it cover?

A: It covers magnetic field and magnetic moment measurement methods, magnetization/demagnetization procedures, magnetic compensation testing, test‑room and facility requirements, and recommended test sequencing and reporting for verification of magnetic cleanliness in both controlled zero‑field and geomagnetic environments.

Q: Who typically uses it?

A: Spacecraft integrators, payload teams (especially magnetometer/science instrument teams), test laboratories, magnetic‑cleanliness engineers, and mission verification/QA personnel.

Q: Is it current or superseded?

A: Published in February 2019 and listed as the first edition (2019). ISO maintains a review cycle for standards; users should confirm the standard's current lifecycle status with their national standards body or ISO if they require the absolute latest revision activity.

Q: Is it part of a series?

A: ISO 21494 is focused on magnetic testing; related work in the same technical area (ISO/TC 20/SC 14) includes development of guidance and design reports for magnetic cleanliness (for example ISO/AWI TR projects). It is used alongside other space test, cleanliness and verification standards rather than being one part of a numbered multipart series.

Q: What are the key keywords?

A: Magnetic testing, magnetic cleanliness, magnetic moment, remnant field, induced field, magnetization, demagnetization, magnetic compensation, spacecraft testing, EUT.