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Climate & Energy

Space Is Full of Rubbish – It’s Everyone’s Job to Clean It Up

Paper10th February 2023

The ongoing space boom provides an opportunity for the commercial sector to step into a leadership role to address the clean-up and mitigation of space debris. The density of objects in orbit around Earth is growing rapidly due to a booming space industry, the increased availability of small satellites at a lower cost and a lack of agreed mitigation strategies or governing policies. Until recently, governments were the main contributors to the creation of space debris and they have left it largely unchecked for the past 50 years owing to a lack of technology and strategic agreements. In coming decades, however, the growing commercial space sector is expected to be the leading cause of debris.

Public and private sharing of responsibility has the potential to facilitate sustainable and long-lasting mitigation strategies, as well as innovation for the development and deployment of space-debris-removal technologies.

With additional large satellite constellations on the horizon, the time to preserve access to Lower Earth Orbit (LEO) is now. SpaceX’s Starlink, OneWeb’s Gen-1 and -2, China’s Guo Wang and South Korea’s Samsung constellations, which contain large numbers of satellites, have heightened concern among experts about the risk of the Kessler Syndrome: a scenario in which the density of objects in LEO is high enough to cause cascading collisions, eventually rendering LEO useless. Don Kessler, who proposed the theory in 1978, stated in 2012 that the Syndrome has “already started” and will unfold over the coming decades.

If left unchecked, the risk posed by space debris to human life will increase as the amount of debris and number of astronauts in orbit increase simultaneously. An oversaturation that renders LEO inaccessible would trap humankind on Earth.

Seven actions undertaken by the global commercial space sector and spacefaring governments can help address historical space debris and mitigate exacerbation of debris in the future:

  1. Investment by large companies in emerging technologies

  2. International consortium of commercial space companies and scientists

  3. Binding international agreement on debris-mitigation goals

  4. Reinvigorate United States–China cooperation

  5. Government financing modelled on NASA’s funding of SpaceX and the replacement of the International Space Station (ISS)

  6. Establish national-level incentive and fee programmes

  7. Fund think-tank programmes and centres focused on space policy

Chapter 1

What Is Space Debris and Why Is it Problematic?

Orbital debris comprises humanmade objects no longer in use. This includes decommissioned or damaged spacecraft, launch-vehicle stages and satellites, as well as debris fragments, typically resulting from collisions or anti-satellite tests. Debris is primarily located in LEO, which is closest to Earth and cheapest to reach. LEO is defined as orbit at 1,000 km above Earth, as opposed to Medium Earth Orbit (MEO) which refers to orbit at 10,000 km, and Geostationary Orbit (GEO), where satellites go around the planet at a distance of 35,768 km.

There are approximately 47,600 trackable objects in space, of which 19,600 are space debris. Between one third and one half of LEO alone is estimated to be saturated with debris. Hundreds of thousands of pieces of this debris are too small to track but can cause significant damage given the speed at which they travel – up to 28,000 km/hr. Even a fleck of paint that has fallen off an old spacecraft and collides with a satellite can cause irreparable, life-threatening damage.

Space debris puts at risk the ability of countries to rely on space assets for defence and intelligence missions as well as supply chain and logistical operations. In the long term, it risks the ability to launch payloads safely into both LEO and more distant, higher orbits. It even poses a risk to astronauts in orbit if debris were to collide with the ISS or a shuttle carrying astronauts to the ISS. As recently as 21 December 2022, the ISS was manoeuvred to avoid a piece of debris, and a spacewalk was cancelled because of the risk to astronauts.

There are two space debris problems that need to be addressed simultaneously:

  • Removing, recycling and preventing collisions between historical space debris created by governments over the past 50 years

  • Mitigating the creation of new debris by commercial space companies, which are now at the helm of the booming industry

Chapter 2

Historical Space Debris

Orbital debris went mostly unchecked for the 50 years following the space race. The US, China and Russia are largely responsible for existing debris. Russia accounts for a majority of the most concerning pieces of debris with the highest likelihood of disrupting space activity.

Removing just a few, large pieces of space debris theoretically has the potential to significantly decrease the Kessler Syndrome over time. To deal with historical debris, there are numerous technologies currently being developed or scaled to track debris and avoid collisions, and to actively remove or recycle it. These technologies, however, are all in development and have not yet successfully removed any debris. Actively deployed technologies are primarily monitoring tools, such as Project ARGUS, the US Space Force’s Space Fence and emerging non-Earth imaging capabilities. Examples of removal technologies in development include:

  • Astroscale is developing an active clean-up service to remove decommissioned satellites.

  • Obruta is developing tethered-net technology to capture and de-orbit, meaning manoeuvring space debris and end-of-life satellites to re-enter Earth’s atmosphere.

  • CisLunar envisages recycling metal space debris and manufacturing it into new parts while in orbit.

Chapter 3

Future Space Debris

Looking to the future, most debris will be created by commercial entities. The commercialisation of the industry and the development of lower-cost small satellites (“small sats”) has led to a spike in launches of payloads. Small sats cost less to build and launch than large satellites, and they can more easily absorb losses, whether due to space debris, collisions or software/hardware failures, without significantly affecting mission. Before 2012, the average number payloads launched annually was 100. For the past five years, the number of payloads launched each year has exceeded that: 1,815 payloads were launched in 2021 alone. Though this does not inherently create debris, it does increase the risk of collisions causing debris and the number of defunct spacecraft in orbit as satellites reach their end of life.

Figure 1

Figure 1 – Payloads launched per year


For active and future space assets, companies are financially incentivised to develop technologies, such as refuelling, to help extend satellite lifespans. Refuelling is also beneficial to companies because operators sometimes manoeuvre their satellites to avoid collisions, but this burns through an already limited fuel supply at a faster rate. Refuelling could also enable satellites to manoeuvre to lower orbits once they are no longer in use, speeding up the time needed to de-orbit. Examples of technologies under development for refuelling include:

  • Orbit Fab is developing an infrastructure of propellent depots and shuttles that can refuel satellites.

  • Maxar Technologies and NASA are testing a spacecraft with robotic arms to refuel satellites and extend their mission or enable them to de-orbit more quickly.

  • Astroscale is offering a docking plate to enable on-orbit servicing of satellites.

Chapter 4

Policy Recommendations

The two space debris problems – historical and future debris – both require public and private action and collaboration. Governments are likely to lean on the commercial sector for space-debris-removal technologies, and policies developed in the commercial sector for debris mitigation will need to be codified by governments and international institutions.

Investment by Large Companies in Emerging Technologies

Although investment in the space industry is still growing, the ongoing economic downturn is expected to disproportionately affect funding of space technologies over the next few years. This risks further delaying the development of solutions to address debris.

If, as Space Capital predicts, companies providing data, insights and critical services sustain their investment, there is an opportunity for them to finance emerging tech through corporate venture capital, as they did before the surge in private venture capital.

Methods for companies to do this include traditional mergers and acquisitions, and the hotly debated special-purpose acquisition companies (SPAC) method, in which small companies go public by merging with a SPAC. Virgin Galactic, for example, merged with Chamath Palihapitiya’s Social Capital Hedosophia.

Spin-off companies, however, are a growing and potentially more viable path forward in a time of economic stress. Sierra Nevada Company (SNC) launched Sierra Space, a ventures group, to invest in innovators in the emerging space market, provide them access to SNC’s capabilities, and “help position them for success as they mature their capabilities and continue their capital strategies”.

Companies could benefit financially as the cost of providing venture capital is almost guaranteed to be lower than an acquisition or merger once the startup is established.

International Consortium of Commercial Space Companies and Scientists

To date, the commercial sector has been relatively successful in establishing standards of responsible behaviour. There are informal agreements among companies to track and avoid debris, and de-orbiting defunct assets is now a standard practice. This, however, only touches the surface of what is possible in terms of policy, liability and enforcement. More regulations and norms will be necessary to mitigate space debris, and there is an opportunity for the commercial sector to have a role in informing those regulations and norm-setting behaviours.

An international consortium of companies and scientists would provide a venue for them to develop, test and recommend to their governments new standards for space debris mitigation and removal. Over time, established responsible behaviours could evolve into norms and inform national policies and international agreements.

A consortium could:

  • Facilitate communications regarding collision risks

  • Brainstorm innovative approaches collaboratively to space-debris mitigation

  • Discuss feasibility of goals and policy implementation

  • Test the viability of complying with potential regulations

  • Recommend innovative policies to their governments outside the consortium

Organisations exist that could lead this effort as a third party, such as the Paris Peace Forum, which leads the Net Zero Space initiative, Space Data Association, Space Safety Coalition and Space Sustainability Rating. If commercial entities were to step into a leadership role within the consortium, it would be important to let companies with international experience take the lead. International companies bring with them an understanding of operating a business across borders, and consequently understanding policy in multiple countries. Furthermore, a balance of power must be achieved not just between large and small companies, but also between those already operating in space and those aspiring to do so, including companies based in emerging and developing countries.

The greatest challenge to an effective international consortium would be the inclusion of companies from countries that lack civil–military boundaries, such as China, or with whom other countries have restrictions on sharing technologies. However, the inclusion of China’s space sector is important given that the country is the second largest spender in space after the United States. Commercial parties to an international consortium, including Chinese space companies, would share a common interest in preserving access to space and their financial security without the level of political baggage that often blocks effective government engagement on the topic.

The involvement of scientists in a consortium is vital as they can provide insight into the physics of space debris, which is often more complicated and unpredictable than it seems. Academics and think-tanks could also contribute to this effort and play a role as policy advisers, as commercial actors may not always understand the feasibility of policy implementation or associated timelines.

Binding International Agreement On Debris-Mitigation Goals

Efforts to establish an international agreement on norms in outer space have either failed, were once successful but are now outdated, or were merely non-binding and therefore often violated by adversarial countries. An outlier is the 2013 Group of Governmental Experts report on Transparency and Confidence-Building Measures in Outer Space Activities, which was hailed as a success after a long history of failures. It is not a binding agreement but can be used as a starting point for a binding international or multilateral agreement.

To secure access to space in the future, a binding agreement between spacefaring nations should:

  • Establish requirements, methods and liability for communication regarding potential collisions of both private and public space assets. This entails not just being liable to provide notification when a country or company is tracking a potential collision, but also having a designated, responsive representative to receive notifications. In one example, the European Space Agency (ESA) provided notification of a conjunction between an ESA satellite and a Starlink satellite but was unable to get in touch with the other satellite owner, SpaceX.

  • Commit to sustainability goals for space debris: to decrease and maintain it at a lower level.

  • Establish requirements and liability for de-orbiting a decommissioned satellite within a certain number of years.

  • Assign responsibility for removing space debris, which may entail holding the main contributors responsible or establishing an international fund to finance removal of the riskiest debris.

  • Agree to repercussions, such as fines or sanctions, for parties, whether governments or companies, that fail to meet communication obligations, de-orbiting requirements or sustainability goals.

This international agreement should be brokered by a rising space power or third-party broker. Rising space powers, namely the European Union, Japan and even South Korea, have a vested interest in mitigating space debris. They may also be able to garner wider support than the US, China or Russia, which are responsible for most space debris to date. As proposed at the 73rd International Astronautical Congress in September 2022, an alternative is a “trusted nongovernmental broker” that could be appointed to facilitate international negotiations, playing the role of a mediator.

An international agreement on space debris could be modelled on the Kyoto Protocol and Paris Agreement on climate change. It should establish binding commitments from all countries for the reduction and mitigation of space debris, as well as penalties, particularly for parties responsible for the most space debris to date.

Reinvigorate US-China cooperation

The US and China are responsible for approximately 50 per cent of space debris. An agreement to remove historical debris and prevent future debris could have a high impact on the sustainability of LEO. It is time for the US to reinvigorate cooperation with China on space debris.

There is a history of successful bilateral cooperation between the US and China to strengthen communications over potential satellite collisions but engagement has been dormant since about 2017. The US-China Civil Space Dialogue, launched in 2015, and Space Security Exchanges that took place in 2016, provide existing fora for conversations.

These conversations should remain focused on sustainability issues, such as commercial regulation, collision warning, debris removal and mitigation strategies, for example. Any discussions regarding a moratorium on anti-satellite (ASAT) tests or weaponisation of space, which are historically contentious topics, should take place separately from any arms-control talks. Otherwise, they put at risk any progress that can be made towards cooperation and sustainability.

A successful agreement would also set a standard for other countries expanding in the space arena. For example, China has a significant influence on the space activities of other countries, primarily in South America, which could have secondary positive impacts if engagement is successful.

Historically, trilateral agreements have been more challenging than bilateral ones due to the greater likelihood of geopolitical disagreements. While a trilateral agreement between the US, China and Russia on space debris would be ideal, it is currently not palatable to the US following Russia’s invasion of Ukraine. Even China’s relationship with Russia has become fraught since the invasion. Instead, the US could pursue a bilateral agreement with China, which has a higher likelihood of success.

Government Financing Modelled on NASA’s Funding of SpaceX and Replacement of the International Space Station (ISS)

NASA provided funding to SpaceX to design, test and develop a launch vehicle from scratch, despite the potential for failure, rather than buying an existing technology. NASA has duplicated this funding method in hopes of fostering a similar success for development of the next ISS. In the case of the ISS, NASA awarded contracts to four different companies to design a new space station by 2025, after which a winner (or winners) will be selected to deliver their station to space.

This funding model has shifted the landscape of the aerospace industry away from massive contracting companies that had little competition domestically but were not enabling the US to compete effectively with China and Russia. Instead, NASA has opted to fund a small company with ambition or multiple companies to emphasise the need to prioritise innovation and lower costs, not just for NASA but for the industry at large. In the case of SpaceX, NASA’s revolutionary early, flexible and low-requirements funding showed that early government investment can help propel a startup into a successful business as well as foster competition, innovation and sustainability.

Government financing of emerging space technologies for debris mitigation should:

  • Aim to develop a new technology, rather than purchase an existing one

  • Have limited or no pre-established requirements or specifications, just an end goal.

  • Take place early in a startup’s life

  • Fund the development of the tech for the wider market, rather than specifically for a government customer, enabling the company to pursue a more sustainable business model

To date, much early investment in startups from NASA and the US Department of Defence has been for launch technologies. With the ORBITS Act, NASA has been directed to establish a programme with the commercial sector to develop active debris-removal technologies, among other actions to mitigate space debris. This provides an opportune moment in the US to enhance public-private partnership on space debris. Other countries should follow suit to adopt NASA’s financing model and enhance public-private partnerships.

Establish National-Level Incentive and Fee Programmes

Leaning on public–private partnerships at a national level, commercial actors and their governments could collaborate to identify which policies work best for their economies and then codify those incentive and fee programmes into regulation. The international consortium could also be used by companies to test various scenarios and develop a unified approach to recommend to governments.

Possible models include charging “orbital use fees” for each new satellite a company places in orbit. To prevent debris rather than just penalise companies for the debris they create, one possibility developed by Moriba Jah is to offer financial incentives for companies that score high on the Space Sustainability Rating and rewards, or “bounties”, for debris that is salvaged or removed.

Fund Think-Tank Programmes and Centres Focused on Space Policy

Individuals who have started their own organisations focusing on space security, such as Marcel Arsenault and Cynda Collins Arsenault founding Secure World Foundation, demonstrate that there is sufficient content, expertise and demand for space-policy research. And yet, to date, very few think-tanks have established programmes or centres focused on space policy, meaning that funding for such efforts is likely lacking. When it comes to think tanks with programmes devoted to space policy, the Center for Strategic and International Studies’ Aerospace Security Project is a rare example of success. Research tends to be by individual scholars at think-tanks who publish on the topic occasionally, such as Doug Ligor at RAND Corporation, Micah Zenko while at the Council on Foreign Relations or Alexandra Stickings at Chatham Institute.

Think-tanks are dependent on funding from private donors, including endowments and grant programmes, and occasionally public funds. Funding is often directed to specific programmes, publications, events or other deliverables. Funders should allocate funding specifically to space policy. Establishing a programme at a leading think tank devoted entirely to space would:

  • Ensure adequate time and resources are devoted to the topic

  • Provide opportunities for public–private engagement

  • Inform countries trying to expand their influence in the space domain

  • Demonstrate to the public the importance of the topic

Chapter 5


The commercial space industry has an opportunity to coalesce and take on a leadership role in space-debris mitigation. This has the potential to fill gaps that governments have struggled with for 50 years, such as facilitating sustainable and long-lasting mitigation strategies and policies, or developing and deploying innovative space-debris-removal technologies. For companies, greater attention to space-debris mitigation would ensure that access to LEO, which their business depends upon, is retained.

An international consortium of commercial space actors and scientists is crucial to establishing national and international standards for mitigation. This consortium is needed to facilitate communication over collision risks and collaborative brainstorming and feasibility testing of policies for debris mitigation. Furthermore, companies could subsequently serve as advisers to their public partners on national policies and international agreements. Separately, large space companies could fund new and innovative space-debris-removal technologies by launching their own spinoff space venture groups.

With the commercial sector stepping up involvement, governments should not relinquish their role, but rather reframe it as a public–private partnership. All governments providing funding to space companies should in part model their financing on NASA’s funding of SpaceX and the replacement ISS. Providing room for failure, supporting startups to build a sustainable business model and fostering healthy competition has the potential to result in game-changing technologies. Finally, national incentive and fee programmes can help to hold companies accountable for their role in space debris but should be informed by commercial actors.

Internationally, an effective binding agreement is worth striving for. Bilaterally, a renewed US–China partnership could help streamline collision notifications, facilitate collaboration of debris removal and set an example to new spacefaring nations.

Finally, funders have a significant role in influencing innovation and space policy in academia. Donors to think-tanks should direct funding specifically to space policy, enabling them to launch programmes or centres devoted to this important subject.

If the commercial space sector does not step up to mitigate debris, the future of existing companies is at stake. Unmitigated debris will make it riskier and more expensive to operate in LEO or higher orbits, and will eventually render space unusable. With private–public collaboration, innovation and policies to hold governments and commercial actors accountable, we can preserve humankind’s access to LEO and ambitions for exploration beyond Earth.

Lead Image: TBI

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