Space Junk Is a Problem We Know How to Solve

In August, a stray upper stage from a SpaceX Falcon 9 struck the moon. Roughly the size of a school bus and weighing 4 metric tons, it hit the lunar surface near Einstein Crater at approximately 5,400 miles per hour, carving out a substantial new crater. Had a similarly massive piece of debris survived reentry and struck a populated area on Earth, it would have caused significant damage and loss of life. And, just last week, large pieces of space debris fell on land in both Minnesota and Indonesia, presumably from a Chinese rocket launched on 14 October. These events highlight an increasingly visible problem of space exploration: Satellite mega-constellations aren’t only transforming our night skies. Humanity’s expansion into space is beginning to reproduce the same take-make-waste model that has caused significant environmental damage on Earth. The number of objects in Earth’s orbit has risen dramatically and is likely to increase several-fold again over the coming decade. In 2010, the active satellite population was roughly 1,000. Today, space surveillance networks track approximately 40,000 objects in the Earth’s orbit. But only around 17,000 of these are still active payloads; the rest are retired satellites, spent rocket parts, and other fragments. When it comes to smaller space debris, the European Space Agency (ESA) estimates that more than 1.2 million debris fragments larger than 1 centimeter are already orbiting Earth. The greatest danger posed by these smaller fragments is that they will collide with functioning spacecraft. Traveling at several kilometers per second, even a small fragment can disable a satellite, while a larger impact can shatter it into thousands of additional pieces. Those fragments can then strike other objects, producing a self-sustaining cascade of collisions known as the Kessler syndrome. The ESA’s latest Space Environment Report, published in September, identifies the potential development of the Kessler syndrome as the most serious long-term threat to space exploration. The consequences of such an event would extend far beyond space, with profound impacts on global infrastructure on Earth. Satellites supporting communications, navigation of shipping and aviation, banking, weather forecasting, climate monitoring, disaster response, and even military early-warning systems could be severely damaged or even completely lost. This would create gaps in essential services and heighten the risk of geopolitical miscalculation, as disrupted communications and surveillance systems could be mistaken for hostile acts by other governments, instead of technical failures. Some projections cited in United Nations space-sustainability discussions suggest that more than 100,000 satellites could be orbiting Earth by 2030, if proposed mega-constellations proceed as planned. As orbital traffic grows, so does the probability that a single collision could initiate further fragmentation and make valuable orbital regions increasingly hazardous or even unusable. Rather than rely on maneuvers to avoid a collision (overseen by surveillance networks such as the U.S. Space Surveillance Network), more systemic solutions are needed. We should not reproduce the same wastefulness that we exhibited on Earth—a wastefulness that brought about the plastics pollution crisis. Instead, we should build a circular space economy, and fortunately, we can use solutions from Earth to do so. Instead of treating rockets and satellites as disposable objects that are launched, used, and then abandoned or burned up, a circular space economy would entail spacecraft designed for durability, repair, upgrading, refueling, and eventual recovery. This is no longer merely a hypothetical idea; it is becoming a major frontier of space technology and commercial innovation. The ESA has set out a vision for a zero-debris approach and a circular space economy by 2050. This approach will keep spacecraft, components, and materials in use through repair, refurbishment, upgrading, reuse, and eventually recycling in orbit. ESA-backed research is also exploring orbital recycling plants and spacecraft designed from the outset for disassembly and material recovery. Circularity could therefore become not only an environmental safeguard but also a foundation for the next phase of space exploration. There are already commercial operators such as ClearSpace and Astroscale that are trying to develop spacecraft capable of approaching, inspecting, and capturing defunct satellites, while robotic arms and standardized docking interfaces could allow satellites to be repaired, refueled, or safely removed. There is also an important connection to critical minerals: A circular space economy could turn orbital debris from a costly liability into a valuable economic resource. Satellites and rocket components contain aluminum and titanium, alongside smaller quantities of cobalt, nickel, and rare-earth elements used in batteries, magnets, electronics, and communications equipment. Rather than allowing these materials to remain stranded in orbit or burn up during reentry, future recovery systems could capture, dismantle, and process defunct spacecraft. Some estimates show that the reuse of space junk could have a net value of between $570 billion and $1.2 trillion. This amounts to somewhere between 5,312 metric tons and 19,124 metric tons of scrap metal that can be recovered, not considering future materials yet to be launched. Recovering and reusing these materials in orbit could reduce the financial and environmental costs of launching replacement materials from Earth. Elon Musk’s SpaceX is no stranger to circular solutions in space. In fact, it was reuse that (quite literally) lifted the company to the forefront of commercial spaceflight. By landing and reflying the Falcon 9’s first-stage booster, SpaceX transformed one of a rocket’s most expensive components from single-use hardware into a repeatedly used asset. It is also less expensive to refly than to build new launchers. A NASA assessment estimated an average cost of around $50 million for a flight using a previously flown booster, compared with roughly $65 million for one using a new booster. Circularity, in other words, is not a constraint on the business model; it is a major source of its competitive advantage. Commercial success has helped turn reusable boosters into an industry standard that China and other launch providers are now pursuing. On July 10, China recovered an orbital-class booster for the first time, catching the returning first stage of a Long March 10B rocket in a net above an offshore platform after it had placed a satellite in orbit. But the solutions are not only technical. Addressing the problem will also require some innovation of the space governance architecture and the resolution of several important legal questions. The core international rules governing space use were written in the 1960s and 1970s, when space activity was the purview of governments and relatively few objects were in orbit. Currently, defunct satellites remain under the jurisdiction and ownership of their registering states, meaning that companies cannot simply capture and repurpose them as abandoned material. Also, existing guidelines provide no standardized procedures for obtaining consent, transferring ownership, or allocating liability if a recovery operation causes damage. Encouragingly, making these zero-waste and circular practices routine would not require constructing an entirely new system of space governance. The foundations already exist in the Outer Space Treaty of 1967, the Space Liability Convention, the Registration Convention, and broader U.N. sustainability guidelines. Several international and intergovernmental bodies already exist as well and have made orbital debris and space sustainability a priority. The space governance architecture must be further updated and operationalized for an era increasingly dominated by commercial operators such as SpaceX, Amazon Leo, or Geespace (a private Chinese commercial operator backed by Geely) and their satellite mega-constellations. To support sustainability in orbital space, measures to prevent or minimize the creation of debris were introduced at the international level by the U.N. Committee on the Peaceful Uses of Outer Space (COPUOS) in 2007 in the form of the Space Debris Mitigation Guidelines. Furthermore, the Inter-Agency Space Debris Coordination Committee (IADC)—an international forum of space agencies, authorized governmental and intergovernmental entities which coordinates efforts to deal with space junk—first launched its Debris Mitigation Guidelines in 2002, with subsequent updates, the latest one in 2025. An important update has been a new constellation-wide perspective. The revised guidelines recognize that risks depend not only on whether each satellite is eventually removed but also on where thousands of satellites are placed and how they travel through other orbital shells. These guidelines have not been entirely unsuccessful: They have helped establish widely accepted practices such as passivating spent rocket stages, limiting routine debris release, and disposing of satellites after use. Compliance is also improving among commercial operators. But the guidelines were never strong enough to reverse the overall growth in risk. There’s still a mismatch between being useful mitigation guidance drafted 20 years ago and being fit for purpose in the age of mega-constellations. And the guidelines are still voluntary and too weakly enforceable to manage the full systemic risks. Under the Outer Space Treaty, states remain responsible for supervising private space activities, while the 1972 Liability Convention channels responsibility for damage through launching states, rather than directly to commercial operators. Back then, space exploration was solely the domain of specialized government agencies and the military, and the involvement of private companies and commercial operators as we see today was not anticipated. Modernizing the liability framework could introduce binding end-of-life obligations, standardized consent procedures for servicing, and clearer liability rules for the growing number of commercial actors. Ideally, circularity would be a condition of receiving a launch license. Even deposit-based systems such as “space junk bonds” have been proposed by insurers as a more market-based approach. Such as system would require operators to help cover future recovery and cleanup costs. This approach would be modeled on surety bonds, which have been used to ensure the decommissioning of oil rigs and mines. Before launch, satellite operators would pay a bond proportionate to the number, mass, orbital lifetime, and collision risk of their spacecraft. The bond would be refunded once safe de-orbiting and recovery were completed and verified. The upcoming 60th anniversary of the Outer Space Treaty in 2027 offers a timely opportunity to address these governance gaps. The treaty itself need not be renegotiated; instead, states could develop and adopt a “Protocol on Circular Space Operations”— a supplementary instrument developed through COPUOS that would translate existing treaty principles into practical guidance and implementation. This protocol could clarify procedures for transferring ownership of defunct satellites, obtaining consent for their capture, allocating liability during removal missions, and recognizing recovered materials as economic resources. Space debris and the risk of catastrophic collisions are not unavoidable consequences of human space exploration. The ideas already exist, the technologies are emerging, the institutional foundations are in place, and the economic opportunities could be substantial. Albert Einstein once argued that “a new type of thinking is essential if mankind is to survive and move toward higher levels.” If space exploration is to take humanity to those higher levels and further into outer space, we must move beyond disposable spacecraft and toward circular design that enables repair, reuse, and recovery.