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Our mission is to encourage space actors to design & implement sustainable space missions and operations

The Space Sustainability Rating (SSR) provides a rating system informed by transparent, data-based assessments of the level of sustainability of space missions and operations. 

Practical and actionable recommendations are shared with space operators on how to improve their sustainability performance.

All space actors can engage with our platform for action-focused collaboration centered on the rating system to support research and leverage best practices

Making top-of-class, safe & responsible behaviour a norm in space

The opportunities offered by the space economy can only be harnessed if we keep the space environment sustainable & safe in the long-term.

However, in the rapidly evolving space ecosystem, a shift is needed in how actors pursue sustainability and the ways in which sustainability practices are measured.

A new way to incentivize safer conditions for operating in space

The space ecosystem has a critical role to play in protecting space for future generations.

By voluntarily engaging with the SSR, space actors will have an opportunity to demonstrate sustainability commitment & scorecard and help reduce the risk of space debris, on-orbit collisions, and unsustainable space operations.

The SSR will enable space actors to enhance the sustainability and safety of their missions through an incentive:

To design missions compatible with sustainable and responsible operations

To operate missions considering impact to the orbital environment & on other operators

To communicate transparently on space sustainability & debris mitigation efforts, demonstrated by a “bronze”, “silver”, “gold”, or “platinum” rating badge

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silver badge
gold badge
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The SSR is designed as a composite indicator, aggregating and weighing 6 modules encompassing the various aspects of the mission design & operation - tested and fine-tuned with leading operators.

Explore them in details HERE.

our partners

The Space Sustainability Rating is a trail-blazing effort initiated by the World Economic Forum in 2016 and developed by a consortium involving the European Space Agency, the Massachusetts Institute of Technology, BryceTech and the University of Texas at Austin.

eSpace - EPFL Space Center has been selected in 2021 to drive implementation according to the vision of its ambassadors. As of 2023, the SSR is managed by an independent association.

All space actors are welcomed to join the SSR.

We are striving to assemble a community of forward-thinking actors to continuously enhance the rating system.

Ansys, Debris-X, the Nihon University, and Stellar have joined the SSR as Founding Members and early supporters of the SSR.

ALTER TECHNOLOGY, EnduroSat, Neuraspace, Privateer, the Secure World Foundation and Slingshot Aerospace have become Association Members.

Our members are instrumental in advancing the SSR and helping to achieve a joint ambition for space sustainability. Join them!

get in touch

Contact us to learn more about the SSR, explore how you can get involved and apply for a rating


The SSR is an initiative hosted by eSpace - EPFL Space Center seeking to foster voluntary and bold action by satellite operators to reduce the risk of space debris, on-orbit collisions, and unsustainable space operations.

It provides an incentive for satellite operators to design and implement sustainable missions design and operations in outer space, through an innovative and inclusive approach consisting of:

  • a rating system informed by transparent, data-based assessments of the level of sustainability of space missions – without disclosing confidential mission data and proprietary information; and
  • practical guidance on how to improve sustainability performance and responsible practices.

The rating system is the result of a five-year development process initiated in 2016 by the World Economic Forum’s Global Future Council (GFC) on Space Technologies, and the metrics used are widely recognized by scientific communities, regulators, and industry as efficient space sustainability assessment criteria.

Space debris pose significant challenges to the safety of current and future operations in space. In 2022, around 5400 active satellites are sharing orbits around Earth with more than one million objects larger than 1cm - increasing the risk of collisions and the loss or disruption of space-based infrastructure. As thousands of spacecrafts are planned to be launched in the coming decade, and without internationally binding guidelines, implementing tools to incentivize space actors and foster responsible behaviour will be key to ensure long-term sustainability of the space environment. 

The SSR offers an innovative and practical solution to addressing the orbital challenge by rewarding sustainable design and responsible behaviour, as well as increasing the transparency of organisations’ debris mitigation efforts.

It evaluates the implementation and efficiency of collision avoidance and post-mission disposal strategies, assesses the ability to detect and track a spacecraft, promotes compliance to existing space debris mitigation guidelines and rewards operators sharing data contributing to space situational awareness.

Operators going through a rating will be evaluated but will also benefit from the support of the SSR team to identify the actions that can be taken in order to increase the mission’s sustainability.

The Space Sustainability Rating is a non-profit association recognized by EPFL and hosted within eSpace – EPFL Space Center. The rating system is independent, neutral and transparent: its methodology is available online and the team is available to address any question which may arise. 

The rating methodology was developed by a multi-disciplinary consortium composed of BryceTech, the Space Enabled research group at Massachusetts Institute of Technology, the European Space Agency Space debris office and the University of Texas at Austin and the World Economic Forum.

The development process of the rating methodology spans two years (between 2019 to 2021) and was also supported by satellite operators through alpha and beta testing phases to ensure its robustness and relevancy.

Read More about the SSR’s origin:

The rating process is managed by the SSR team within eSpace who is responsible for gathering the inputs, giving guidance on the completion of a rating, and providing results and recommendations to the operators.

The final score resulting from the assessment is computed from the evaluation of six individual modules and from the verification level of the information provided to the SSR issuer. The score is jointly computed by eSpace, MIT (Detectability, Identification and Trackability module), and ESA (Mission index module).

The SSR also draws from the principles outlined in the UN Guidelines and considers specific decisions about design, operations and post mission disposal that reduce risk of collisions, shorten orbital time for debris and increase space situational awareness.

The rating methodology is detailed on The Rating webpage.

The SSR provides an assessment of the sustainability level of a space mission. A mission is defined as a functional unit of spacecraft, launch vehicle, and mission related objects aimed at providing a specific service, by means of design and operations, for which they need to access and use part of the space environment.

A mission can consist of a single satellite, a satellite and a launch vehicle, or combinations of these elements. The rating is computed considering the contribution from all the objects.

    • Satellite operators can engage with the SSR to undertake a rating and in order to better understand how to improve their mission sustainability. Each rating pertains to one mission and can be re-computed in case parameters change or if recommendations from the initial rating report are implemented.
    • A flat fee applies for the rating. In order to enable academic projects and startups with limited financial resources to apply for a rating, a special discount on the subscription fee is offered to these entities. Please contact the team to receive a tailored offer.
    • Any organisation can join the SSR as an association member to get involved in the work of the SSR, provide input on the rating system, and support communications and policy efforts.

The SSR is designed as a guiding instrument for space operators in their sustainability journey. It is a unique tool providing an accurate assessment of the current sustainability performance, and helping to identify where improvements can be made along the way - contributing to establishing best practices for the space sector.  By voluntarily taking part in the rating, spacecraft operators, launch service providers and satellite manufacturers will share a single point of reference externally describing their mission’s level of sustainability.

The Space Sustainability Rating can be applied to any type of mission, at any mission phase. The rating however only remains valid for a given mission phase, as significant changes can occur from a mission phase to another. As the SSR issuer needs to be able to certify that a mission complies to the SSR criteria, the rating is only valid for subscribed operators. On demand re-evaluation of the rating can be requested at any time if recommendations are implemented in the mission.

There are three ways to support SSR’s activities:

  • Satellite operators can request to be rated by subscribing and benefit from the SSR’s recommendations to implement sustainable design and operation practises in their mission and showcase their efforts towards space sustainability.
  • Any organisation can join the SSR as an association member in order to be involved in the discussions about the rating and participate in shaping its evolution. The SSR Association’s goal is to federate satellite operators and any entity having an interest in space sustainability such as insurers, policy-makers, and researchers to facilitate discussions about the evolution of the rating system. Visit the Get engaged page for more information.