The rising number of satellites launched in recent years, driven by the emergence of new actors and commercial satellite constellations in low-Earth orbit, has amplified concerns about preserving the long-term use of the space environment. Each year, the space industry sees record numbers of satellite launches, while not enough satellites are removed from already congested orbits at the end of their lives.
While space traffic is increasing exponentially, sustainability regulations and guidelines have mostly remained unchanged since the early 2000s. The importance of space sustainability for the long-term equitable and accessible use of space has been internationally agreed upon for decades. However, in this rapidly evolving tech sector, a shift is needed in how actors pursue sustainability and the ways in which sustainability practices are measured.
The concept of carbon footprint is widely recognized as a critical environmental sustainability indicator to quantify the environmental performance of products, companies or countries. The lack of such an indicator in the space industry has propelled the work of an international and transdisciplinary consortium to design, develop and administer the Space Sustainability Rating (SSR). The SSR was first proposed by the World Economic Forum and supported in its design by the Space Enabled Research Group at MIT, the European Space Agency, the University of Texas at Austin, and BryceTech. In 2021, the EPFL Space Center, or eSpace, was selected to host and operate the SSR. The rating system is inspired by the successful adoption of rating systems in other industries, such as the Leadership in Energy and Environmental Design (LEED) certification in the green building and construction industry. Designed as a composite indicator, the SSR offers a global definition of sustainable design and practices in all stages of a mission’s lifecycle, from design to in-orbit operations and disposal.
In their own interests, operators have already been pursuing sustainable measures, reflected in recent demonstrations of commercially viable active debris removal (ADR) services, increased investments in on-orbit servicing, and missions that include fully demisable design and disposal within five years. National agencies are also taking on their share of sustainability measures. France took the first step in 2008 through the French Space Operation Act, which includes space debris mitigation guidelines and imposes hard design constraints on launches from French Guyana with the obligation for spacecraft to deorbit after launch. As emerging spacefaring nations develop their regulatory frameworks, they are looking at ways to integrate sustainability measures to meet their national obligations under the UN Space Treaties. Despite these efforts, the definition of sustainable behavior in space is not uniform among actors, and it is difficult to quantify, measure and verify these guidelines. The SSR aims at bridging the gap, giving a clear framework to operators on how to measure the sustainability of their missions. The key to the design of the SSR is that it takes a series of metrics based on models previously published by agencies and academic institutes that serve to quantify and measure sustainability decisions taken by operators without disclosing proprietary information about the mission.
The need for sustainability rating systems as a tool to recognize actors for demonstrating their commitment to the long-term sustainability of the space environment and adherence to space debris mitigation practices in the space industry has been supported by the Satellite Industry Association and U.S. Federal Communications Commission. Based on their rating, actors may one day be rewarded through financial and economic incentives that could impact insurance premiums for satellite operators, potentially reducing costs, and potentially leading to more positive customer and public perception, acting as a competitive advantage and offering greater prestige. Ratings such as those implemented in other industries are used in marketing and environmental, social and governance-style corporate reporting, focusing on shifting the attitude towards compliance assessment and highlighting good behavior rather than shaming bad behavior.
Ratings in practice
Speaking to the Financial Times in 2021, Stijn Lemmens, senior space debris mitigation analyst at ESA noted, “If you were an operator in low Earth orbit five years ago, you mostly cared about avoiding debris. Now you have to care about avoiding other operators, too.” In working closely with the SSR beta testers, it is evident that space actors are concerned about the long-term use of the space environment and the risks and challenges due to space debris and the increase in space traffic. The beta testing phase of the SSR development was conducted in 2021 to test and calibrate the SSR before public registration and engage with operators and manufacturers to help improve aspects of the SSR. Several companies, including Airbus, Astroscale, AXA XL, Elseco, Lockheed Martin, Planet, SpaceX and Voyager Space Holdings, have actively supported the SSR’s development, were involved in beta testing, and expressed interest in participating once it is publicly launched.
From the initial ratings that have been reviewed during the beta testing phase, eSpace has noted that space actors valued feedback on their respective missions. They also liked how the SSR design methodology captured the different sustainability elements of their missions. In addition, similar to Corporate Social Responsibility (CSR) demonstrated by companies in other sectors, the SSR is a platform for space actors to showcase their commitment and actions to pursuing long-term sustainability in current and future missions. In the case of startups, having an SSR is a means to provide evidence of their commitment to sustainability. Early indications have proved advantageous to startup investors.
Some space actors have raised concerns about showcasing a high rating if they are the only ones ‘behaving sustainably,’ leading to a potential loss of competitive advantage. However, the earlier these decisions are taken in the design of a mission, the less impact on the overall cost they will have. Through dialog with space actors, the rating team has answered questions about the approach used within the rating calculations to estimate a mission’s impact on the environment and other operators. For example, the ESA Mission Index is a key feature of the SSR score, and it estimates the risk of collision or debris creation based on a mission’s orbital profile. It uses the Environmental Consequences of Orbital Breakups (ECOB) formulation. Another portion of the SSR scores space missions based on the level of difficulty to Detect, Identify and Track the spacecraft, building on work led by the University of Texas and MIT members of the team. The input of space actors has helped ensure these analytic approaches can be applied to various missions.
The economic growth of the space sector goes hand-in-hand with the need to keep the space environment sustainable and safe, allowing for fair and equitable use for outer space activities. Rating systems act as a ‘yardstick’ to measure sustainability design and actions, aimed to recognize, reward, and incentivize actors to pursue long-term sustainability, as well as support the continued revision of sustainability guidelines and norms of behavior. eSpace underwent a transition phase with the SSR consortium, taking over ownership and management of the SSR in 2021. The official launch of the SSR will take place at the 4th Space Sustainability Summit in London on June 22-23.
Emmanuelle David is the executive director of eSpace, an interdisciplinary unit responsible for the federation of space activities at Switzerland’s Ecole Polytechnique Fédérale de Lausanne (EPFL), leading a research initiative on sustainable space logistics. Minoo Rathnasabapathy is a research engineer at the Massachusetts Institute of Technology (MIT) Media Lab, where her work focuses on the intersection of technology, policy, and humanity. Minoo serves as a member of the World Economic Forum Global Future Council on Space. She earned her Ph.D. in aerospace engineering from RMIT University, researching the impact dynamics of novel materials used in aerospace structures.