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On the night of April 28th, Amazon initiated its quest to compete with SpaceX’s Starlink through the inaugural launch of its Project Kuiper satellites. With 27 satellites now orbiting Earth, Amazon becomes part of an expanding group of companies aiming to deploy over 1,000 satellites each, resulting in a mega constellation in space. However, this surge in orbital traffic raises concerns about potential collisions, which could lead to catastrophic consequences.
In addition to Amazon and SpaceX, the UK-based OneWeb has established its own satellite constellation, while various Chinese companies are planning similar initiatives. Notably, the Guowang mega constellation, supported by the Chinese government, commenced its launches last year and operates under a shroud of secrecy. Another venture, the commercial Qianfan or Thousand Sails project, began launching in 2023 and aims to deploy up to 15,000 satellites.
A recent report from the European Space Agency (ESA) highlighted that over 2,500 objects were launched into low-Earth orbit in 2024—more than five times the total from any year before 2020. This surge largely stems from the increasing number of commercial satellite launches.
Currently, the quantity of active satellites in orbit rivals that of orbital debris. Projections indicate that, if launch trends persist, we could see nearly 50,000 objects larger than 10 cm in low-Earth orbit by 2050. Over the coming years, an estimated eight satellites could be launched daily, adding a total mass of about four tons of new material to space each day.
These satellites play a crucial role in providing communication and internet access, particularly in remote or disaster-stricken regions. Yet, the increasing saturation of low-Earth orbit poses a significant challenge, as both functional satellites and debris from older missions accumulate.
Experts are calling for comprehensive regulations governing the management of orbital objects, yet the climate of global cooperation necessary for such efforts appears more elusive than ever.
“There is a race to fill low-Earth orbit,” explains Vishnu Reddy, a debris researcher at the University of Arizona.
The concern extends beyond just operational satellites. Millions of debris pieces, some moving at high velocities, complicate the situation. ESA has estimated that over 1.2 million objects in orbit could cause severe damage during collisions. Low-Earth orbit is particularly congested with thousands of commercial satellites, alongside other debris.
The risks are substantial. Should a critical satellite be compromised, or if a series of smaller debris collisions occur, the cumulative effect could generate even more debris, initiating a cascading series of collisions. Experts warn this could render access to space perilous, potentially leading to a scenario where global space initiatives might need to be suspended.
“The satellite operators are obviously tempted to increase their numbers,” states Olivier Hainaut, an astronomer at the European Southern Observatory. “However, an overabundance can lead to collisions. These incidents may initiate phenomena like Kessler Syndrome, potentially rendering various orbits unusable.”
The ramifications of orbital overcrowding are evident. Close constellation positioning can interfere with signal transmissions. Moreover, factors such as climate change are aggravating the issue as greenhouse gases cause the upper atmosphere to contract, hindering its effectiveness in dissipating debris.
While no one advocates for a ban on satellites or mega-constellations, the annual launch of thousands of satellites brings with it consequences that are frequently overlooked. Scholars are increasingly exploring the limitations of orbital capacity and questioning the long-term sustainability of current launch rates.
It’s not the functioning satellites that present the primary challenge. Commercial satellites are monitored and tracked, yet thousands of smaller debris pieces remain unmonitored. As the number of operational satellites grows, so does the risk of collision with these unidentified debris.
Currently, there is no established authority responsible for tracking debris and preventing collisions. The space sector essentially relies on the US government’s tracking information, hoping operators act responsibly.
“Satellite operators must oversee their satellites,” Reddy asserts. “The Space Force catalogues many objects and updates it several times daily, with the expectation that operators can manage themselves based on that information.”
This responsibility extends to deorbiting inactive satellites. SpaceX has gained recognition for effectively deorbiting its non-functional satellites, as experts agree that their Starlink units are designed to descend naturally into the atmosphere after several years, where they disintegrate.
To avoid competition for orbital space, satellite operators have designated different orbits for their units. For instance, Project Kuiper satellites are launched into higher altitudes compared to Starlink, but transitioning through alternative orbits remains a pressing concern.
“What goes up must come down,” Reddy remarks. “Eventually, Kuipers will need to re-enter and will have to pass through Starlink’s orbital zone. What then?”
Amazon has not addressed inquiries regarding its strategies for the safe deorbiting of Kuiper satellites or managing potential conjunctions.
Averting Catastrophic Scenarios
Potential conflicts among satellite operators could escalate, as collision avoidance incurs significant costs. In situations where, for instance, a Starlink satellite and a Project Kuiper satellite are on a collision course, experts refer to this as a conjunction. Subsequently, one or both satellites may need to adjust their orbits using limited fuel reserves.
“Now, both Starlink and Kuiper teams will have to determine who will deplete fuel to dodge a collision, which can impact profitability,” Reddy states.
This scenario, while potentially manageable, is among the more favorable outcomes, as both satellites have accountable operators. Conversely, smaller debris lacks any such oversight.
“A productive day occurs when two operating satellites face a conjunction,” explains Reddy. “A concerning day arises when inoperative objects collide. Then all one can do is hope they don’t scatter debris.”
The precise amount of debris generated from any collision is difficult to predict, contingent on various factors such as impact speed, trajectory, and material composition. Unfortunately, industry secrecy around satellite construction compounds the uncertainty regarding the potential damage from impacts.
This predicament is exacerbated by mega constellations where thousands of satellites occupy the same orbital lane. Should a malfunction leading to an explosion occur, a single company might need to maneuver hundreds of satellites, potentially causing numerous conjunctions in the process.
“The hope is that it won’t happen,” Reddy notes. “But if it does, it can escalate rapidly.”
Experts focused on space debris are not opposed to the idea of satellite companies achieving profits, but they emphasize the need for these firms to spearhead initiatives aimed at establishing collision prevention norms and guidelines: “It is in their financial interest to develop a foundational set of rules.”
Companies need not await the slow pace of international diplomacy to assume responsibility for managing orbital traffic. “SpaceX has far more experience managing a mega constellation than any regulator we’ve encountered,” asserts Reddy. They could proactively propose strategies to handle conjunction scenarios, relieving the onus from governments to develop comprehensive plans.
Proactively addressing this issue appears vital for satellite companies, especially as more organizations launch their own mega constellations, including some based outside the US.
The stakes become particularly concerning when considering the potential for hundreds of conjunction events between Starlink and Chinese mega constellation satellites. This leads to critical questions: “Who will make the maneuver? Will parties wait to see who acts first?”
Reddy advocates for a formal collaboration framework among satellite firms to ensure clear guidelines for maneuver coordination in the event of satellites on a collision path. “A well-defined approach is preferable to waiting until a collision is imminent to scramble for contact information,” he suggests.
The threat of satellite collisions is far from hypothetical. In 2019, a close call between a Starlink satellite and the European Space Agency’s Aeolus satellite highlighted the potential risks. ESA conducted a last-minute maneuver to avert a collision that could have generated extensive debris across a busy orbital region.
This incident was alarming, particularly because ESA struggled to contact SpaceX for coordination and intervention. SpaceX later stated that an email alerting them to the potential collision had been overlooked due to a software issue.
The ongoing challenge underscores the absence of a legal framework for managing satellite collision risks. Experts agree that space requires a regulatory system akin to air traffic management, yet such regulations are currently lacking, and the threat of a potential conjunction looms constantly. The close call between Aeolus and Starlink 44 exemplifies a regulatory vacuum that persists today, as highlighted by Holger Krag, ESA’s Head of Space Safety Programme, during a recent space debris conference.
“Whenever active spacecraft coexist, cooperation becomes essential. Clear communication and coordinated action are vital,” Krag asserted. However, there is no legal mandate outlining who is responsible for this communication or how collisions should be averted. “We are far from establishing clear operational protocols to address situations like that faced by Aeolus and Starlink.”
Furthermore, with an increasing number of satellites in orbit, ESA has warned that the current process of manually avoiding collisions through position adjustments for each satellite may become unfeasible.
To formulate enforceable regulations for space use, international agreement through a body like the United Nations would be necessary, given that no single nation can regulate space activity. Yet, the political will for such a collaboration appears scant. The last substantial international space legislation, which continues to inform current legal frameworks, emerged from the 1967 Outer Space Treaty, originally drafted without consideration for private corporate operations, leaving a regulatory gap regarding space debris responsibilities.
This situation epitomizes a tragedy of the commons. While there is a shared desire to maintain accessibility to space, few stakeholders are stepping up to address the issue head-on.
Josef Aschbacher, director general of ESA, encapsulated this dilemma at the conference: “The message is crystal clear: space debris is a pressing issue, and we must take action.”
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