ISO TS 21979-2018 PDF

Full title and description

ISO/TS 21979:2018 — Space environment (natural and artificial) — Procedure for obtaining worst case and confidence level of fluence using the quasi-dynamic model of earth's radiation belts. This technical specification defines an engineering calculation method, based on a quasi-dynamic model of the Earth's radiation belts, to estimate particle fluences (worst‑case and associated confidence levels) received by spacecraft for design and analysis purposes.

Abstract

The document specifies a procedure that uses a quasi‑dynamic model reproducing fluctuations of the Earth's radiation belts and selects easily obtainable, highly correlated input parameters (index values) to predict variations. It defines how to calculate fluence for a given orbit and operation period to support satellite design and related engineering analyses.

General information

• Status: Published (Technical Specification).
• Publication date: 2018-09 (Edition 1).
• Publisher: International Organization for Standardization (ISO).
• ICS / categories: 49.140 (Space systems and operations).
• Edition / version: Edition 1 (ISO/TS 21979:2018).
• Number of pages: 18 (ISO edition). Note: some national/adopted published copies (PD/BSI listings) reference a 28‑page layout for their publication formats.

Scope

Provides a standardized engineering procedure to derive worst‑case particle fluences and associated confidence levels for spacecraft using a quasi‑dynamic representation of Earth's radiation belts. The scope covers selection of model input parameters, orbit and operation period definitions, and calculation steps intended for satellite design and similar engineering applications. The method is explicitly presented as an engineering approach (informative note in the TS).

Key topics and requirements

• Quasi‑dynamic model of the Earth's radiation belts to reproduce temporal fluctuations and variability.
• Procedure to calculate particle fluence for a specified orbit and operational period (worst‑case and confidence level outputs).
• Selection and use of input index parameters that are readily available and highly correlated with radiation belt variations.
• Guidance for applying results in spacecraft design margining and risk assessment (engineering method note).
• Produced under ISO/TC 20/SC 14 (space systems and operations) to complement other space‑environment standards and guidelines.

Typical use and users

Engineers and analysts in the satellite and spacecraft industry (systems engineers, space environment specialists, radiation effects engineers), spacecraft integrators, and organizations performing mission analysis or design verification. Typical uses include worst‑case radiation fluence estimation for component and system design margining, mission assurance, qualification testing input, and risk assessments related to the space radiation environment.

Related standards

Standards from ISO/TC 20/SC 14 and related ISO space‑environment documents that address observed fluences, plasma environments, and test/qualification practices are closely related. Examples frequently referenced in the same domain include ISO 12208 (observed proton fluences and confidence selection), ISO 19923 (plasma environments for worst‑case potential differences), and other guidance/standards for small spacecraft design and testing. National/adopted PD versions (for example BSI PD copies) exist for distribution in some markets.

Keywords

space environment; radiation belts; proton/electron fluence; quasi‑dynamic model; worst‑case analysis; confidence level; satellite design; space systems; ISO/TC 20/SC 14.

FAQ

Q: What is this standard?

A: ISO/TS 21979:2018 is a technical specification that specifies a procedure using a quasi‑dynamic model of Earth's radiation belts to obtain worst‑case particle fluence estimates and associated confidence levels for spacecraft design and analysis.

Q: What does it cover?

A: It covers the calculation method (including orbit and operation period definitions), selection of input index parameters correlated with radiation belt variations, and steps to produce worst‑case fluence and confidence level outputs for engineering use. It is provided as an engineering method for satellite design purposes.

Q: Who typically uses it?

A: Spacecraft designers, radiation effects engineers, systems engineers, mission analysts, and test/qualification teams who need standardized procedures to estimate radiation fluences for design margins, testing, and risk assessment.

Q: Is it current or superseded?

A: As published it is ISO/TS 21979:2018 (Edition 1). According to ISO lifecycle information the document is published and subject to periodic review (ISO technical publications are typically reviewed on a 5‑year cycle); users should check the ISO catalogue or national standards bodies for any amendments or revisions since 2018.

Q: Is it part of a series?

A: It is one of several ISO documents addressing space environment and space systems produced under ISO/TC 20/SC 14. While not a numbered "series" in the sense of sequential parts, it complements other ISO standards and technical specifications covering observed fluences, plasma environments, testing, and small spacecraft practices.

Q: What are the key keywords?

A: Space environment, radiation belts, fluence, worst‑case, confidence level, quasi‑dynamic model, satellite design, space systems, ISO/TC 20/SC 14.