Removing space debris requires action and caution
Over the icy tundra of Siberia in 2009, a derelict Russian military satellite, Kosmos-2251, slammed into an active communications satellite, Iridium 33, at speeds in excess of 26,000 miles per hour. Both were immediately smashed to smithereens.
As a result of this single collision, approximately 1,800 large pieces of space debris, each capable of destroying any spacecraft unfortunate enough to cross its path, remain in orbit to this day and for the foreseeable future.
Depending on who you ask, space debris is either a nonissue that will solve itself or a critical problem that threatens the future of space exploration. We interviewed dozens of experts across industry, academia and the regulatory landscape to better understand which of these viewpoints is closer to the truth, and to consider what ought to be done going forward.
What is space debris?Far from homogenous, space debris includes any nonfunctional human-made object in space, including rocket parts that have been abandoned in orbit after having completed their mission, defunct satellites, fragments from unintentional and intentional orbital collisions and items released during operations. These sources have multiplied to create a large amount of space debris orbiting Earth.
According to NASA, there are over 30,000 objects larger than a softball in orbit, traveling at speeds up to 18,000 miles per hour.
This debris is spread across all three of the main regions of space around Earth: low-Earth orbit (LEO), medium-Earth orbit (MEO) and geosynchronous equatorial orbit (GEO). As its name suggests, LEO is the closest to us, extending up to 2,000 km from the Earth's surface.
It is the most crowded region of the three and, in addition to hosting the International Space Station, it is the region where SpaceX, OneWeb and other well-funded companies are currently sending tens of thousands of new satellites as part of their constellations. Perhaps not surprisingly, LEO is the region with the most debris. As a result, it tends to be the focus of much of the discussion around the issue.
Above LEO, satellites in MEO and GEO are also threatened by space debris. This is important because these orbits host a number of crucial satellites, including navigation systems in MEO such as the American GPS and European Galileo, and critical GEO-based communication satellites. Satellites in GEO are able to maintain a single point above the Earth (this special orbit is possible because the satellite is orbiting around Earth at the same speed the Earth is rotating).
Given the altitude of both MEO (2,000 km-36,000 km) and GEO (~36,000 km), de-orbiting the satellite is not a viable option - the current solution when satellites retire is to move them to unused orbits called graveyard orbits," further contributing to the growth of space debris above us.
Why does space debris matter?The existence of space debris is concerning for many reasons, with physical collisions being the most obvious. The possible risk caused by space debris is magnified by the incredible speed at which debris typically travels. According to NASA, there are over 30,000 objects larger than a softball in orbit, traveling at speeds up to 18,000 miles per hour. At that speed, any one of these objects is capable of completely destroying a spacecraft.
Even debris just 1 cm in diameter can disable an operational spacecraft, while even smaller fragments can cause huge problems as well. Indeed, a fleck of paint was enough to damage a window on the International Space Station, which has been forced into maneuvers to avoid larger, potentially catastrophic debris 28 times since 1999, including three times in 2020 alone.
Unfortunately, tracking all of this debris has proven to be an arduous challenge. For starters, only objects larger than 10 cm in diameter are currently tracked by the North American Aerospace Defense Command (NORAD). However, there are likely 900,000 objects less than 10 cm but larger than 1 cm, and tens of millions of objects smaller than 1 cm that are not tracked by the current system but that are still capable of causing significant damage. Of particular concern is the range between 1 cm and 10 cm, which has appropriately earned the moniker of lethal nontrackable debris, or LNT.
Space junk poses other challenges as well. Astronomers lament that light pollution from objects in orbit hampers observation of the night sky. The reliance of observatories - often involving equipment costing hundreds of millions of dollars - on long exposures makes debris particularly problematic. Another worry is Kessler syndrome," which takes its name from NASA scientist Donald Kessler.
In 1978, Kessler postulated that more space debris would increase the likelihood of collisions, which in turn would lead to more space debris, and so on, in an exponential growth that may end up compromising orbital operations. In other words, the issue could evolve into a never-ending spiral that eventually renders LEO unusable and possibly impenetrable.
StakeholdersBefore considering how to respond, it is important to understand the landscape of those affected by space debris.
Launch providers are among the most crucial players - after all, their business models hinge on their ability to put payloads into orbit. They are also part of the problem. Launcher parts (i.e., spent upper stages) left in orbit have been, in the words of professor Lorenzo Casalino of the Polytechnic University of Turin, piling up for decades."
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He believes launch providers have been among the most critical contributors to space debris." However, some newer launch companies, such as Rocket Lab, do not leave any piece of their rockets in space. Instead, they de-orbit the stages, which causes them to burn up upon reentry into Earth's atmosphere.
Satellite operators are also a crucial component of the ecosystem. On one hand, they are the ones most responsible for the overcrowding of space; on the other, they are the most likely victims of space debris. Mike Safyan of Planet, which has over 150 satellites in orbit, notes that mitigating space debris is in the interest of satellite operators," and that many are already incorporating maneuverability and de-orbiting technologies into their satellites.
For example, OneWeb, a large constellation operator, is designing its satellites to be de-orbit ready." Darren McKnight, Technical Director at Centauri, a satellite operator, explains that operators are faced with a significant decline in overall reliability" as their systems are increasingly affected by a constantly growing space debris cloud, and thus incentivized to act. Sara Spangelo, CEO and co-founder of Swarm Technologies, says many private companies have already started to implement measures for space debris mitigation. Swarm Technologies has proven that it can consistently track its tiny satellites and recently added active attitude and propulsion control to maneuver out of the trajectory of debris.
These strategies help ensure that while the 10 cm by 10 cm by 2.8 cm (the size of a grilled cheese sandwich) satellites are providing connectivity around the world, they do not contribute to the growth of the space debris cloud.
An interesting role is played by insurance companies. Chris Quilty, a commercial space expert, notes that while satellite insurance remains relatively uncommon - fewer than a tenth of satellites in LEO are covered by insurance - insurers are likely to play an increasingly large role as the risk of collisions becomes more likely. Chris Kunstadter, global head of space at AXA XL, a major commercial insurance provider, adds that insurers have been active in terms of pushing for stricter regulation, as insurance is often a key component of regulatory proposals.
One group that is often overlooked, but that has the potential to strongly affect the future path toward the sustainable use of space, is comprised of the end users of space-based services. This encompasses anyone from telecommunications customers to users of imaging data to transportation companies relying on satellites to track their ships and planes. As OneWeb's VP of Regulatory Affairs Ruth Pritchard-Kelly points out, if end users demand sustainability, as they have in other sectors (e.g., retail, mining, etc.), it would likely force launch providers and satellite operators to act.
Finally, there is a new stakeholder that is trying to solve the challenge of space debris. Startups such as Astroscale and D-Orbit are making progress toward commercializing the removal, or at least mitigation, of space debris. Another example is LeoLabs, a ground-based space mapping provider, whose phased-array radars are capable of tracking debris as small as 2 cm. Dan Ceperley, founder and CEO of LeoLabs, believes his company's advanced tracking capabilities will allow launch providers and satellite operators to be responsible for the objects they put into space. If mapping, mitigating and removing space debris turn out to be profitable endeavors, the private sector may already have the incentives it needs to clean up its act.
Regulatory considerationsNotwithstanding the promise of space debris mitigation technology, it is possible that regulators will be forced into action. Due to the intricacies of the space sector and the many stakeholders, regulatory bodies could provide stability and a guiding framework for companies around the world. However, the regulatory picture is uncertain given how decentralized space regulation tends to be.
While the United Nations Office for Outer Space Affairs (UNOOSA) exists to promote international cooperation in outer space, it is lacking in its ability to enforce regulations at the international level, being limited to providing secretarial support to the COPUOS (Committee for Peaceful Use of Outer Space). As a result, regulation in the industry has always been a tricky patchwork of country-level rules, with parties occasionally resorting to adopting flags of convenience" in search of the nation offering the most favorable regulatory conditions.
In spite of this patchwork, the United States has emerged as the most powerful potential source of regulation given both its weight within the industry as well as its International Traffic in Arms Regulations (ITAR). ITAR is a U.S. regulatory regime controlling the manufacture, sale, distribution and use of defense and space-related articles that has made it costly and difficult - if not impossible - for U.S. players in the space industry to flag-shop or otherwise do business without adhering to U.S. regulations. As a result, any effective regulations governing space debris are likely to emerge from the U.S.
One of the many observations that has echoed through numerous interviews revolves around how U.S. regulations have not kept up with the rapid development of technology, with rules and guidelines dating back to a period when only NASA and the Soviet space program launched satellites into space, and when the idea of private entities possessing the ability to easily and inexpensively access space was unthinkable," in the words of Alessandro Rossi of the Italian National Research Council.
Over the last decade, launch costs have decreased by an order of magnitude; this, combined with the development of CubeSats and other miniature satellites, has dramatically lowered the cost of sending payloads to space. The private sector has responded by promising to send thousands of satellites into LEO over the next few years. It is unlikely that rules designed to regulate a handful of satellites the size of school buses will be adequate for this new reality.
Within the U.S., several agencies deal with the use of space, and the best source of future regulation remains a point of contention. A 2018 White House directive sought to make the Commerce Department the traffic cop" of space. Meanwhile, some believe the Federal Aviation Administration (FAA), which already regulates launches and reentries, is in the best position to effect change. Another key player is the Federal Communications Commission (FCC), which is responsible for regulating satellite transmissions.
According to Laura Montgomery, an expert in space law and the former head of the FAA's space law branch, the FCC certainly interprets its regulatory mandate as extending to space debris."
The experts we spoke to generally seemed to believe that these agencies are unlikely to aggressively pursue new regulations in the near term. Professor Montgomery noted that regulators tend to move slowly," and that the collisions that have happened to date have yet to lead to Congressional action" on this issue. Professor Zac Manchester of Carnegie Mellon University suggested regulatory agencies are often understaffed and lacking the technical expertise" to address the problem of space debris anytime soon.
Others noted that while the FCC implemented new rules to mitigate orbital space debris back in April, these rules did little to change the status quo - operators will now be required to submit more safety disclosures, but the body stopped short of introducing stricter orbital debris criteria." To summarize, it appears that new overarching regulations are unlikely to be implemented anytime soon.
Where many see regulatory bodies as the ones holding the stick, there has been a push toward the creation of a carrot, an incentive for stakeholders to play an active role in addressing space debris. This is what the World Economic Forum (WEF), together with MIT's Space Enabled Research Group at their Media Labs, European Space Agency, University of Texas at Austin, and Bryce Space and Technology, has been working on with the development of the Space Sustainability Rating (SSR).
WEF's Nikolai Khlystov describes the SSR as a voluntary rating system for space (not dissimilar to what already exists for the energy class of home appliances or LEED for buildings) that aims at incentivizing good behavior. The hope is that the SSR, or a similar system, will be widely adopted by the industry. As an example, the WEF sees insurance companies making good use of the rating, as it could be used to determine premiums, offer discounts or even refuse insurance for underperformers.
The case for actionAt this point, the space industry and its stakeholders have two options. They can either set up a framework that can address the problem of space debris, or continue on the current path, with little regulatory oversight and even less enforceability on a global level surrounding the sustainable use of space.
Looking at the history of space debris, we can safely assume that if nothing changes, the amount of debris will continue to grow, particularly within the more crowded LEO orbits. Without a comprehensive framework for end-of-life, it is only a matter of time before more collisions like the Kosmos-Iridium one will cause an order of magnitude increase in space debris, making it nearly impossible to clean up LEO.
There is a saying in aviation: Regulations are written in blood." The implication is that regulations are often founded on lessons learned from events that cost property or lives. One more major collision could force the hand of the international space community and lead to harsh regulations that could be negative for those within the private space industry that have not already adopted sustainability as a business imperative.
The case for cautionOn the other hand, the space industry and regulatory bodies could come together to shape guiding transparent rules to deal with the challenges posed by space debris without hindering progress in the private space sector.
Any framework addressing the issue of space debris should be a cooperative, international effort. Regulatory bodies can leverage the fact that the sustainable use of space is in the interest of all market participants - after all, space debris is a costly problem, as well as a potential safety issue, for both operators and users. Today, many companies in the private space sector are in favor of greater accountability for this reason.
In addition, the case could be made that private companies would be more effective than governments at removing space debris from highly congested orbits. The technology of space debris removal is still in its early stages - Astroscale and other startups have not yet launched their services. However, they are beginning to make significant progress, and it is hard to imagine a future where this industry will not be critical in cleaning up space debris.
The path forwardIdeally, we hope to see the private sector rise to the occasion. Surely market participants acknowledge the long-term importance of keeping space free of debris, and we believe this represents an attractive problem for startups to tackle. We would also welcome creative ideas, such as prizes for researchers who come up with the best solutions for removing space debris.
However, at some point, it is likely that the issue of space debris will need to be addressed with regulation. In particular, we would urge the regulators best-positioned to act - those in the United States - to tackle the issue, as they stand the best chance of crafting enforceable regulation.
One of the biggest obstacles currently is that different agencies touch different parts of the satellite ecosystem (e.g., the Commerce Department, the FAA and the FCC) and responsibilities often overlap. We would encourage Congress to clarify this issue and empower a single agency to take the lead in setting rules to address the issue of space debris.
We would, however, caution against sweeping regulation that fails to consider the long-term consequences of such action. Professor Montgomery puts it best, As a former writer of regulations, I know that they tend to get set in stone, and this has the potential to hamper innovation."
This was the key issue with the debacle surrounding the Kicksat-2 project, says Professor Manchester. The project was meant to demonstrate the cutting-edge technology of microsatellites in a safe manner, but was delayed for years due to concerns from the FCC before being approved in 2019 with zero modifications to the original design. Montgomery adds that, If regulators act too quickly, they run the risk of creating rules that are not ideal and that are almost impossible to fix."
For this reason, we would encourage regulators to take their time to understand the issue and to work closely with other stakeholders to develop a set of guidelines over time, rather than rushing to a conclusion too soon.
Ultimately, we hope regulators and the commercial players can work together to find a lasting solution in the relatively near future, rather than waiting for a catastrophic failure before taking action.
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