Space Law Glossary
28 essential terms for space regulation, including the EU Space Act proposal (COM(2025) 335).
Authorization
The formal approval granted by a National Competent Authority (NCA) permitting an operator to conduct specific space activities. Required by many national space laws; the EU Space Act proposal (COM(2025) 335, Art. 6) would require it before Union space operators provide space services.
Collision Avoidance Maneuver (CAM)
An orbital adjustment performed by a spacecraft operator to reduce the probability of collision with another space object, typically executed when conjunction analysis indicates unacceptable risk levels.
Conjunction Assessment
The process of analyzing predicted close approaches between space objects to determine collision probability and inform decisions about avoidance maneuvers. The EU SST system provides conjunction warnings to operators.
De-orbit
The controlled or uncontrolled descent of a spacecraft from orbit, resulting in atmospheric re-entry. The IADC guideline for LEO is 25 years after end of mission; the EU Space Act proposal (COM(2025) 335) sets no year figure and leaves the maximum LEO orbital lifetime to an implementing act (Annex V point 3.4.2).
Delegated Acts
Commission acts that supplement or amend non-essential elements of an EU regulation. The EU Space Act proposal (COM(2025) 335, Art. 113) would empower the Commission to adopt them on, among other things, Agency fees (Art. 41(3)), the method for fines (Art. 56(9)), the order of preference for end-of-life disposal (Art. 70(4)) and the cybersecurity requirements in Annex VII (e.g. Art. 79(4)). Technical debris thresholds would come from implementing acts (Art. 70(3)); the proposal contains no insurance minimum.
Design for Demise
Spacecraft design approach that ensures complete or near-complete destruction during atmospheric re-entry, minimizing the risk of debris surviving to reach Earth's surface.
End-of-Life (EOL)
The EU Space Act proposal (COM(2025) 335, Art. 5(42)) defines end of life as the instant when a spacecraft or launch vehicle orbital stage is permanently turned off, nominally as it completes its disposal phase, re-enters the Earth's atmosphere, or can no longer be controlled by a space operator. Disposal obligations: Art. 70(1)(c) and Annex V point 3.
EU SST (Space Surveillance and Tracking)
The European Union's system for monitoring space objects, providing conjunction warnings, and supporting space situational awareness. The EU Space Act proposal (COM(2025) 335, Art. 64) would require Union spacecraft operators to subscribe to the collision avoidance services of the EU SST provider and to report the actions they take after a high interest event alert.
Geostationary Orbit (GEO)
A circular orbit approximately 35,786 km above Earth's equator where satellites appear stationary relative to a point on Earth. GEO satellites have specific disposal requirements involving transfer to graveyard orbits.
Graveyard Orbit
An orbit significantly above GEO (typically 300+ km higher) used for disposal of geostationary satellites at end-of-life. Transfer to graveyard orbit preserves the valuable GEO belt for active missions.
In-Orbit Servicing (IOS)
Space activities involving close proximity operations with other spacecraft, including inspection, refueling, repair, upgrade, or relocation. Subject to enhanced authorization requirements due to collision risk.
IADC Guidelines
Space debris mitigation guidelines published by the Inter-Agency Space Debris Coordination Committee, widely used as the technical baseline for debris prevention and disposal. The EU Space Act proposal (COM(2025) 335) does not refer to them; it sets its own requirements in Art. 70 and Annex V.
LEO (Low Earth Orbit)
Orbital region from approximately 160 km to 2,000 km altitude. The EU Space Act proposal (COM(2025) 335) leaves the maximum LEO orbital lifetime after end of mission to an implementing act (Annex V point 3.4.2); it sets no 5-year figure.
Life Cycle Assessment (LCA)
A systematic analysis of environmental impacts throughout a product's life, from raw material extraction through manufacturing, operation, and disposal. The EU Space Act proposal (COM(2025) 335) would require Union space operators to calculate the environmental footprint of their space activities over the whole mission lifecycle (Art. 96(2), 97(2)) and to submit an Environmental Footprint Declaration with the authorisation application (Art. 96(4)).
National Competent Authority (NCA)
The public authority responsible for space authorisations under national law. Under the EU Space Act proposal (COM(2025) 335, Art. 28), each Member State would designate or establish a competent authority responsible for the authorisation and supervision of Union space operators, with supervisory, investigatory and sanctioning powers (Art. 30).
Operator
Any natural or legal person that conducts or intends to conduct space activities. This includes satellite operators, launch service providers, ground segment operators, and in-orbit servicing providers.
Orbital Regime
A classification of orbits based on altitude and characteristics, including LEO, MEO (Medium Earth Orbit), GEO, and HEO (Highly Elliptical Orbit). Different regimes have different regulatory requirements.
Passivation
The removal of all stored energy sources from a spacecraft at end-of-life, including depleting propellant, discharging batteries, and venting pressure vessels. Required to prevent fragmentation events.
Proximity Operations
Spacecraft maneuvers conducted in close vicinity to another space object, typically within a few kilometers. Subject to enhanced safety requirements and coordination obligations.
Re-entry
The return of a space object to Earth's atmosphere, either controlled (targeted to unpopulated areas) or uncontrolled (natural decay). The EU Space Act proposal (COM(2025) 335, Annex V point 3.5.3) would require spacecraft operators to assess whether parts survive re-entry and to set out measures to reduce the casualty risk.
Space Activity
In the EU Space Act proposal (COM(2025) 335, Art. 5(13)), a set of operations when carrying out activities in outer space, in particular operation and control of space objects (including for re-entry), launch services, operation of launch sites, exploration activities, in-space operations and services (ISOS), and the monitoring and disposal of space debris.
Space Debris
Non-functional human-made objects in space, including defunct satellites, rocket bodies, fragmentation debris, and mission-related objects. The EU Space Act proposal (COM(2025) 335) addresses debris mitigation in Art. 61 (launchers) and Art. 70 with Annex V (spacecraft).
Space Object
Any human-made object launched or intended to be launched into outer space, including satellites, launch vehicle stages, and any components thereof. The launching State registers space objects under the Registration Convention (Art. II). The EU Space Act proposal (COM(2025) 335, Art. 5(1)) defines a space object as a human-made object sent to outer space, including a spacecraft and the launch vehicle orbital stage.
Space Object Registry
Under the EU Space Act proposal (COM(2025) 335, Art. 24), the Agency would set up a Union Register of Space Objects (URSO) registering authorised Union space operators, registered third-country operators and international organisations. The UN Register is kept by the UN Secretary-General under the Registration Convention (Art. III).
Space Situational Awareness (SSA)
The knowledge and characterization of the space environment, including tracking of space objects, space weather monitoring, and near-Earth object observation.
Sustainability Report
The EU Space Act proposal (COM(2025) 335) does not provide for a periodic sustainability report. Its sustainability rules work through an Environmental Footprint Declaration submitted with the authorisation application (Art. 96(4)) and an EF certificate (Art. 98).
Third-Party Liability
Legal responsibility for damage caused to parties not involved in a space activity, including damage to other operators' spacecraft, ground infrastructure, or persons and property on Earth.
Transfer of Authorization
The process by which an authorization is reassigned from one operator to another, requiring NCA approval and demonstration that the new operator meets all applicable requirements.
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