ISO 27875:2019

Overview

ISO 27875:2019 - Space systems - Re-entry risk management for unmanned spacecraft and launch vehicle orbital stages - defines a framework to assess, reduce, and control risks posed to people and the environment when unmanned space vehicles re‑enter the Earth’s atmosphere. It covers both natural (uncontrolled) and controlled re‑entry scenarios and is intended for use during planning, design, review and operations for missions where re‑entry is inevitable. The standard explicitly excludes spacecraft with nuclear power sources and winged systems intended for targeted landing.

Key technical topics and requirements

• Re‑entry safety programme: Establish and maintain a programme to minimise casualties and environmental damage; integrate with system safety activities.
• Re‑entry Risk Assessment and Mitigation Plan (RRAMP): Prepare, update and obtain authorization for a RRAMP as part of the safety data package. Annex A lists typical RRAMP contents.
• Organizational oversight: Appoint safety representatives with authority to access data, halt activities or reject documents; conduct phase reviews and manage waivers/deviations.
• Risk assessment methods:
  • Natural re‑entry: Estimate the expected number of casualties (Ec) using casualty-area, orbital inclination and population density (Annex C describes calculation guidance). For natural re‑entry the likelihood is treated as 1.0 and risk is driven by Ec.
  • Controlled re‑entry: Plan landing area, design features, contingency notifications and post‑re‑entry activities; perform specific risk assessments and non‑conformance handling.
• Risk‑reduction measures:
  • Design measures to reduce survivability of debris on re‑entry.
  • Operational measures including controlled re‑entry planning, designated impact areas (typically uninhabited).
• Environmental risk assessment: Assess ground pollution potential and include mitigation in RRAMP.
• Documentation and process: Follow ISO 17666 risk‑management process (Annex B) and retain traceable records for reviews and authorization.

Practical applications and users

ISO 27875:2019 is practical for:

• Spacecraft and launch vehicle designers and manufacturers
• Satellite operators and mission planners
• Launch service providers and range safety teams
• Safety engineers and programme managers preparing RRAMPs
• National safety authorities and regulators overseeing re‑entry compliance

Use cases include mission design reviews, end‑of‑life disposal planning, contingency planning for re‑entry events, and establishing organizational safety oversight.

Related standards

• ISO 24113 - Space debris mitigation requirements (background and complementary guidance)
• ISO 14620‑1 / ISO 14620‑2 - System safety and flight safety activities
• ISO 17666 - Risk management process and principles

Keywords: ISO 27875:2019, re‑entry risk management, spacecraft re‑entry, launch vehicle orbital stages, RRAMP, expected number of casualties, controlled re‑entry, natural re‑entry, space systems safety.