PD ISO TS 20991-2018 PDF

Full title and description

STB PD ISO/TS 20991:2018 — Space systems — Requirements for small spacecraft. This technical specification defines minimum requirements and high-level design, launch, deployment, operation and disposal considerations for small spacecraft (mini-, micro-, nano-, pico-, femto- and CubeSats) to ensure safety, harmlessness to co-passengers and launcher, and debris mitigation.

Abstract

This specification sets out minimum, top-level requirements applicable across the life cycle of small spacecraft. It is intended to harmonize baseline safety and debris-mitigation expectations for low-cost and mass-limited missions and to provide newcomers and small teams with clear, internationally agreed requirements for design, launch interface, deployment, operation and disposal. The document refers to existing normative standards where appropriate and is addressed to small spacecraft developers, dispenser providers and launch operators.

General information

• Status: Withdrawn (original Technical Specification withdrawn and replaced by a 2025 International Standard).
• Publication date: 20 July 2018 (Edition 1, Technical Specification).
• Publisher: International Organization for Standardization (ISO) — published as ISO/TS 20991:2018 (also made available through national adoption routes, here shown with the STB PD prefix).
• ICS / categories: 49.140 (Space systems and operations).
• Edition / version: Edition 1 — ISO/TS 20991:2018 (Technical Specification).
• Number of pages: 6 (concise Technical Specification).

Scope

ISO/TS 20991:2018 provides minimum, generic requirements for the safe design, launch compatibility, deployment, operation and end-of-life disposal of small spacecraft irrespective of mission profile. The scope explicitly covers a wide range of small-spacecraft categories (mini, micro, nano, pico, femto and CubeSats) and is intended to be applied by spacecraft developers, dispenser providers and launch operators to ensure safety of the launch stack and to reduce orbital debris risk.

Key topics and requirements

• Definition of “small spacecraft” categories and relevant terminology for consistent application.
• Launch interface requirements and dispenser/launcher compatibility checks to protect co-passengers and launcher integrity.
• Safety-related design requirements addressing hazards during integration, launch and deployment.
• Debris-mitigation and end-of-life disposal expectations aligned with existing space-debris guidance.
• Operational constraints and requirements to minimise risk during on-orbit phase.
• Reference and cross-reference to applicable international standards and normative documents for specific technical areas (e.g., debris mitigation, dispenser interfaces).

Typical use and users

Used by small satellite developers (academic teams, start-ups, small companies), CubeSat project teams, dispenser and payload-attachment designers, launch and mission planners, and regulatory or licensing bodies seeking a short, internationally agreed baseline for safety and debris-mitigation expectations. Also useful to launch-service providers evaluating payload compatibility and risk.

Related standards

Commonly referenced / related documents include ISO 24113 (space debris mitigation), ISO 26869 (launcher/dispenser interfaces and related guidance), ISO/TR 18146 and other space-systems engineering and safety standards. The 2018 Technical Specification has subsequently been replaced by ISO 20991:2025 (published as the International Standard updating/replacing the TS). Users should consult ISO 20991:2025 for the current, published international standard.

Keywords

small spacecraft; CubeSat; nano‑satellite; micro‑satellite; launch interface; dispenser; safety requirements; debris mitigation; end‑of‑life disposal; ISO/TS 20991.

FAQ

Q: What is this standard?

A: ISO/TS 20991:2018 is a concise Technical Specification that defines minimum requirements for small spacecraft across design, launch, deployment, operation and disposal phases to help ensure safety and reduce debris risk. It was published by ISO in July 2018.

Q: What does it cover?

A: It covers generic, top-level requirements applicable to a range of small-spacecraft categories (mini, micro, nano, pico, femto and CubeSats), including launch interface and dispenser compatibility, safety controls, operational constraints and expectations for disposal and debris mitigation.

Q: Who typically uses it?

A: Small-satellite developers (universities, start-ups), CubeSat teams, dispenser manufacturers, launch-service providers, mission planners and regulatory/licensing authorities that need a short, internationally agreed baseline for safety and debris-mitigation requirements.

Q: Is it current or superseded?

A: ISO/TS 20991:2018 has been withdrawn and superseded by ISO 20991:2025, which is the current published International Standard (see ISO 20991:2025 for the authoritative, updated requirements). Users should adopt ISO 20991:2025 for the latest, active requirements.

Q: Is it part of a series?

A: It sits within ISO/TC 20/SC 14 (Space systems and operations) and is related to other ISO standards addressing spacecraft safety, debris mitigation and launcher/dispenser interfaces (for example ISO 24113 and related technical reports and standards). The 2018 TS was a first formal, compact international set of requirements for small spacecraft and has now been formalized as ISO 20991:2025.

Q: What are the key keywords?

A: Small spacecraft, CubeSat, nano‑satellite, launch interface, dispenser, safety, debris mitigation, disposal, ISO/TS 20991.