Guidance

Technical framework for implementing planetary protection requirements

Published 8 May 2025

1. Purpose  

The purpose of this framework is to provide clarity to operators and regulators on UK policy for meeting our planetary protection obligations. This framework should be used in conjunction with relevant legislation and regulations by any entity seeking an operator licence for space activities for all missions that involve interactions with celestial bodies in our Solar System (referred to as “missions”).

2. Context

Planetary protection is the avoidance of harmful contamination of outer space as well as the protection of Earth against potential hazard posed by extra-terrestrial material carried by spacecraft returning from other Solar System bodies. It is a policy goal of the UK Government to ensure appropriate planetary protection measures are taken by UK licensed space activities to safeguard the environment on Earth and in space from potential harmful contamination arising from national space activities.  

The UK is signatory to a number of international treaties that govern activity in space. The Outer Space Treaty 1967 is the bedrock of international space law and sets out how states bear responsibility for their national activities in space, whether such activities are carried out by governmental or non-governmental entities. The UK’s obligations stemming from the Outer Space Treaty 1967 are implemented in our national legislation in the Space Industry Act 2018, which governs activities carried out in the UK, and the Outer Space Act 1986, which governs activities carried out by UK entities overseas.  

3. Why we are Implementing this Technical Framework

Planetary protection is part of the UK’s international commitments to a safe, sustainable space environment. Article IX of the Outer Space Treaty 1967 commits the UK to conduct its space activities to avoid harmful contamination of the Moon and other celestial bodies, and also adverse changes in the environment of the Earth resulting from the introduction of extraterrestrial matter. 

The UK needs to have clear processes in place to ensure it fulfils its international obligations under the Outer Space Treaty 1967. Without a robust planetary protection framework, the UK risks: 

• non-compliance with international treaties 

• hindering scientific investigations, such as the search for extraterrestrial life

• contamination or damage to planetary bodies and Earth 

• damaging its reputation as a responsible spacefaring nation

• creating inconsistencies in regulatory processes for UK-based space operators

As more UK industry and academic organisations are considering developing missions to the Moon, Mars and other celestial bodies, this framework seeks to align the UK’s space activities with global best practices, ensure sustainable space exploration, and maintain international collaboration in the space sector. 

A robust planetary protection technical framework is a key enabler of our continuing scientific investigations of the Solar System, investigating how life started here on Earth and searching for life on other planets. An inability to observe proper planetary protection measures could negatively impact our ability to carry out these scientific investigations, cause damage to the environments of Earth or other planetary bodies and harm the UK’s reputation as a responsible member of the spacefaring community.  

Planetary Protection is a responsibility that the UK takes seriously through its active participation on the COSPAR (Committee for Space Research) Panel on Planetary Protection and the establishment of the UK Planetary Protection Advisory Panel.  

This framework sets out how Mission planners can address planetary protection requirements for the conduct of Missions to the Moon and beyond within the Outer Space Act 1986 and the Space Industry Act 2018.  

4. Which activities does this framework apply to? 

This framework applies to UK operator licences (Missions) under the Outer Space Act 1986 and the Space Industry Act 2018 where there is a risk of forward or backward contamination associated with a planned encounter with planetary bodies or celestial objects (i.e. missions to the Moon or beyond Earth Orbit).  

5. Who do UK mission planners need to engage? 

The Civil Aviation Authority is the UK’s independent regulator for space and considers planetary protection implications under the Outer Space Act 1986 and Space Industry Act 2018. In considering planetary protection implications the regulator consults with relevant experts as appropriate, including the UK Space Agency and the UK Planetary Protection Advisory Panel (PPAP), which is comprised of technical experts from both academia and Industry alongside representatives from the Civil Aviation Authority (CAA) as the UK’s independent space regulator.  

6. Background and international context 

To inform this framework and ensure the UK adheres to international good practice, in 2022 the UK Space Agency commissioned a report into planetary protection entitled “A UK Framework for Planetary Protection: A Lunar Case Study” (Olsson-Francis, 2022). This report examined and evaluated approaches for planetary protection from partner agencies, identified global good practices and applied this to the UK regulatory context. The outcome of the report contained several recommendations, which have been implemented through the establishment of the UK Planetary Protection Advisory Panel and within this framework. 

7. Technical Framework for implementing Planetary Protection Requirements for Lunar and Beyond Earth Orbit Missions  

7.1 Missions should adhere to the COSPAR Planetary Protection Policy.  

The UK is obligated as a signatory of the Outer Space Treaty 1967 to conduct its activities in space so as to avoid harmful contamination of the Moon and other celestial bodies and also adverse changes in the environment of the Earth resulting from the introduction of extraterrestrial matter and, where necessary, adopt appropriate measures for this purpose.  

To ensure the UK is compliant with these obligations, the expectation is that operators can demonstrate compliance by setting out how they adhere to the principles outlined in the COSPAR Planetary Protection Policy^{[footnote 1]}. As stated in the Policy, the planetary protection requirements vary on the target planetary body and the mission type. As a member of the COSPAR Panel on Planetary Protection, the UK Space Agency plays a role in the development and amendment of the Policy. 

All UK-licensed Missions with a planned encounter with a planetary body should adhere to the COSPAR planetary protection policy as global good practice. Adherence to the policy will be assessed by the CAA as the Independent Regulator.  

7.2 A recognised standard (such as the European Cooperation for Space Standardisation (“ECSS”)) on planetary protection is recommended to be used as a basis for developing procedures to implement the COSPAR policy within Mission design. 

ECSS ensures a standardised technical approach to implementation of the COSPAR Planetary Protection Policy. Following a recognised standard process will ensure UK operators’ processes are consistent and interoperable with current international practice and coordinate existing ESA and NASA standards, ensuring that UK-based operators and suppliers have clear, consistent guidelines that work for both UK and international-based missions.  

Handbook ECSS-U-ST-20C is based on the COSPAR policy and guidelines. The approach co-ordinates existing standards to ensure that the documentation covers the needs and obligations of international partners for joint missions or contributions to a third party mission and includes:  

• planetary protection management requirements

• technical planetary protection requirements for robotic and human missions (forward and backward contamination)

• planetary protection requirements related to procedures

• document Requirements Description and relation to the respective reviews 

Using the ECSS standard for the implementation of the COSPAR guidelines will ensure that UK planetary protection requirements guarantee interoperability with major partners as well as laying out clear technical requirements.   

Operators may follow an alternative standard (i.e. use a standard other than ECSS, such as the NASA Technical Standards System (“NTSS”), or other means to demonstrate compliance with the COSPAR Planetary Protection policy)  as long as the approach can demonstrate it meets the requirements of the COSPAR Planetary Protection Policy. 

7.3 The UK Planetary Protection Advisory Panel and Reporting to COSPAR    

ECSS-U-ST-20C outlines the need to establish an organisation which oversees the planetary protection requirements, reports to COSPAR, and manages compliance. In line with ECSS-U-ST-20C, a UK Planetary Protection Advisory Panel has been established, consisting of representatives from the UK Space Agency and the Civil Aviation Authority and relevant experts from academia and industry.  

The UK Planetary Protection Advisory Panel may provide advice to the regulator, the Civil Aviation Authority as appropriate^{[footnote 2]} , including planetary protection categorisation and requirements for Missions based on applicants’ self-assessment, subject to the consideration of statutory information sharing restrictions. 

The UK Space Agency representation on the COSPAR Panel on Planetary Protection will report on the planetary protection compliance of UK Missions.  Relevant documentation within the scope of the COSPAR Policy will be provided to the COSPAR Planetary Protection Panel. 

Any information processed by UK Space Agency and the UK Planetary Protection Advisory Panel will be handled and protected appropriately and all personal data will be stored and processed in accordance with General Data Protection Regulation requirements. Mission data will be stored by the UK Space Agency as required under the COSPAR Planetary Protection Policy.

1. 2024 COSPAR PP POLICY ↩

2. Members of the PPAP are required to sign non-disclosure agreements and conflict of interest declarations. ↩