ISO 20991:2025

This document describes minimum requirements for small spacecraft. Small spacecraft may employ untraditional spacecraft development and management philosophy. These spacecraft projects are usually budget-limited or mass-limited, which makes a single (exclusive) launch unaffordable. The scope of this document encompasses different categories of small spacecraft — so-called mini-, micro-, nano-, pico- and femto-, as well as CubeSat, spacecraft. Therefore, for the sake of convenience, the term "small spacecraft" is used throughout this document as a generic term. Regardless of the development philosophy, there are minimum requirements every spacecraft complies with. This document explicitly states those requirements and also refers to existing applicable standards. In that sense, this document serves as the top document to cover the minimum requirements for various stages of small spacecraft system life-cycle — with emphasis on design, launch, deployment, operation, and disposal phases. In this way, (1) safety, (2) harmlessness to co-passengers and launcher, and (3) debris mitigation, are all assured. This document is addressed to small spacecraft developers, as well as dispenser providers and/or the launch operators.