The space economy of the 21st century looks very different than the early days of space exploration when centralized, government space programs dominated. In recent years, both hardware and launch costs have decreased drastically, and technological advances have made it possible to build satellites that are as small as a Rubik’s cube. These developments have allowed dozens of private entities to enter the burgeoning commercial space market, with companies such as SpaceX and Amazon planning to send thousands of satellites into lower Earth orbit over the next decade in groups called “mega-constellations,” which have the potential to revolutionize global communications.
Currently, there are approximately 6,500 satellites (about half of which are active) zipping around our planet at speeds approaching 20,000 miles per hour, but this number is projected to balloon to more than 100,000 by 2030. With this exponential increase in space traffic, scientists are worried about overcrowding in lower Earth orbit leading to collisions that cause the proliferation of space debris, which could have catastrophic consequences for humankind. But the international framework on space law – which was crafted during the Cold War when only a handful of governments had space programs – pre-dates the space debris problem, and subsequent efforts to mitigate it with voluntary measures have been criticized for not doing enough.
In this article, we’ll take a deeper look at the space debris problem and what can be done to tackle it.
The growing threat of space debris
Space debris is defined as any human-made object in orbit that no longer serves a useful function. It can include non-functional spacecraft, abandoned launch vehicle stages, mission-related debris, and fragmentation debris. According to NASA, more than 27,000 pieces of orbital debris are tracked by the Department of Defense’s global Space Surveillance Network (SSN) sensors, but much smaller debris pieces exist that can’t be tracked. The agency estimates that there are approximately 23,000 pieces of debris larger than a softball, half a million pieces of debris the size of a marble or larger (up to 0.4 inches), and approximately 100 million pieces of debris about .04 inches and larger orbiting the Earth.
Space debris can stick around in Earth’s orbit for decades, and even a small fleck of material can do significant damage to anything it hits when traveling at thousands of miles per hour. Not only does space debris endanger human spaceflight missions, such as the International Space Station, but scientists are worried that the fragments created from collisions could set off a cascade of self-perpetuating collisions until the lower Earth orbit is blanketed in a hazardous minefield of debris that would make any use of space essentially impossible for generations, a phenomenon known as the Kessler syndrome. This would have catastrophic consequences for global communications, space exploration and travel, and the operation of weather satellites, GPS satellites, and surveillance satellites.
How is space regulated?
Like the oceans on Earth, space is governed through international law. There are five existing United Nations treaties that form the foundation of space law. Of these, the Outer Space Treaty and Liability Convention are most important to the issue of space debris, so we’ll explore those briefly.
Treaty on Principles Governing the Activities of States in the Exploration and Use of Outer Space, including the Moon and Other Celestial Bodies (1967)
The “Outer Space Treaty,” which came into force in January 1967, provides the basic framework on international space law. It establishes that outer space shall be free for exploration and use by all states, and that this exploration and use should be carried out “for the benefit and in the interests of all countries.” In addition to prohibiting any nation from claiming sovereignty to outer space, the treaty prohibits nations from stationing nuclear weapons or other weapons of mass destruction in space, and requires that the Moon and other celestial bodies should be used “exclusively for peaceful purposes.” The treaty also states that nations will be responsible for all national space activities, whether they’re carried out by governments or private entities under their jurisdictions, and that states are liable for damage caused by their space objects.
Convention on International Liability for Damage Caused by Space Objects (1972)
The “Liability Convention,” which came into force in September 1972, elaborates on Article 7 of the Outer Space Treaty. It establishes that a launching state will be liable to pay compensation for damage caused by its space objects on the surface of the Earth or to aircraft, and liable for damage due to its faults in space. It also outlines procedures for the settlement of claims for damages.
The Liability Convention has been invoked one time, in 1978, after the Cosmos 954 Soviet satellite crashed over Canada upon re-entry. A settlement was reached, and the Soviets assumed responsibility for most of the damage and cleanup costs.
International law fails to address problem of space debris
While they do outline the broad principles that states should abide by pertaining to the exploration and use of space, the five treaties that form the foundation of international space law do little to govern how states should actually behave in space. A significant problem with the current international legal framework is that it doesn’t define or prohibit the production of space debris, meaning that there are no legal consequences for the creation and non-removal of space debris for the responsible state. The definition of “space objects” makes no distinction between active or inactive satellites, and although fragments and components are included in the definition for legal purposes, nothing in the treaties compels states to remove debris from Earth’s orbit to prevent the over-cluttering that increases chances of collisions.
Furthermore, the fault-based system established in the Liability Convention presents significant challenges to debris removal, especially when a private company is involved. According to the law, states are responsible for all space objects launched under their jurisdictions and there are no provisions for abandonment of space objects. States are simply not incentivized to take the risk of something going wrong with another entity removing debris they are responsible for. In any case, with the proliferation of so many small fragments, it has become impossible to trace and attribute everything, leaving a large amount of debris with no “owner.”
Another problem with the existing framework is its vague language. For example, the Outer Space Treaty doesn’t clarify what counts as “peaceful purposes,” and while nuclear weapons and weapons of mass destruction are explicitly outlawed, conventional weapons aren’t addressed. This matter has become significant to the problem of space debris with the rise of anti-satellite technology that can create thousands of pieces of debris with a single launch.
UN addresses space debris with adoption of non-binding Mitigation Guidelines
The Scientific and Technical Subcommittee (STSC) of the United Nations’ Committee on the Peaceful Uses of Outer Space (COPUOS) began considering and addressing the risks associated with space debris in the mid-90s. This work culminated in the UN’s adoption of the Space Debris Mitigation Guidelines in 2007, based on guidelines developed by the Inter-Agency Space Debris Coordination Committee (IADC), which were non-binding guidelines that all member states were encouraged to implement through national legislation and/or policies governing space activities. The guidelines made seven recommendations that states should: limit debris released during normal operations; minimize the potential for break-ups during operational phases; limit the probability of accidental collision in orbit; avoid intentional destruction and other harmful activities; minimize potential for post-mission break-ups resulting from stored energy; limit the long-term presence of spacecraft and launch vehicle orbital stages in the low-Earth orbit region after the end of their mission; and limit the long-term interference of spacecraft and launch vehicle orbital stages with the geosynchronous Earth orbit (GEO) region after the end of their mission.
Rise of anti-satellite missile testing increases space debris threat, creating urgency for action
Critics of using non-binding instruments such as the UN’s Mitigation Guidelines to address the space debris problem argue that these unenforceable, voluntary measures aren’t effectively holding states accountable for the space debris they create. Despite mitigation efforts being adopted by several states, concerning incidents over the last 15 years have escalated tensions and significantly increased the volume of space debris in Earth’s orbit, making it increasingly apparent that the current international framework is inadequate for governing the rapidly evolving and growing space industry of the 21st century.
In January 2007, an anti-satellite weapon test conducted by China destroyed an old weather satellite 537 miles above the Earth, blasting an estimated 3,500 pieces of trackable debris into Earth’s orbit. In February 2009, two communications satellites—the active commercial Iridium 33 and the derelict Russian military Kosmos 2251—accidentally collided, destroying both satellites and creating at least 2,300 pieces of large debris in addition to many smaller pieces. In March 2019, India launched an anti-satellite test that, although it generated a comparatively low number of debris (about 60 large pieces), created another dangerous precedent for states adding to the debris problem and facing no consequences for it. This trend continued in November 2021, when a Russian anti-satellite test shot down an old Soviet satellite and launched over 1,500 pieces of debris into space that endangered astronauts on the International Space Station.
In 2019, COPUOS adopted new Guidelines for the Long-term Sustainability of Outer Space Activities, which encouraged states to comply with the 2007 Mitigation Guidelines, develop or improve tracking systems for space debris, and investigate and consider new measures to manage the space debris population in the long-term. But like the Mitigation Guidelines, the guidelines are voluntary and non-binding, and leave the legal issues surrounding space debris unanswered by the five space treaties still unaddressed. With commercial space activity poised to explode over the next decade, experts have sounded the alarm that further action from the international community is urgently needed to both avoid military conflicts and address catastrophic threats caused by space debris to the sustainability of outer space for future exploration, science, and economic activity.
In 2021, the UN established a working group that will convene in 2022 and 2023 to create new norms, rules, and principles on responsible behavior in space, with addressing activities that escalate tensions and generate space debris as top priorities. States, scholars, international organizations, and NGOs have varying opinions on what shape further action should take, and significant challenges remain. Some believe that the space debris problem can only be solved with a new, binding treaty or through clarifying binding protocols to the existing space treaties, but critics note that this approach is unlikely to succeed given states’ reluctance to agree to binding protocols. And in any case, negotiating a new treaty is an extremely slow process. Others, such as the Outer Space Institute, are urging the UN to adopt a kinetic anti-satellite test treaty ban as a way to prevent the further creation of space debris, but although there are positive signs that an agreement could be reached in the long-term, the process could take years, if not decades.
Whatever the next steps, time is not on our side. As Donald Kessler, the retired NASA senior scientist who first articulated the Kessler syndrome phenomenon in the late 1970s, explained in Scientific American, “There is now agreement within the community that the debris environment has reached a ‘tipping point’ where debris would continue to increase even if all launches were stopped.” While the worst-case scenario may be a far-off possibility right now, the threat increases with each debris-producing incident. To protect the future peaceful use of space for all mankind, the international community must come together on an effective solution to the space debris problem – before it’s too late.
