8 minute read
Removing space junk: The missing piece of the puzzle
By Rory Holmes ClearSpace Chief of Staff and UK Managing Director and Chief of Staff in Executive Management
As our reliance on space infrastructure continues to grow, so does the concern over the proliferation of space debris in Earth's orbits. While efforts have been made to limit the number of derelict satellites and rocket bodies left in orbit and mitigate collision risks for operational satellites, there is still a missing piece to this complex puzzle: the remediation of space debris. Remediation, the process of removing defunct objects from orbit, is a crucial step toward ensuring the sustainability of space activities. This article explores the challenges posed by space debris, the importance of remediation efforts, and the groundbreaking initiatives aimed at removing space junk, making our orbits safer and more sustainable.
Collisions fuel collisions
Currently, there are a million human-made objects, ranging in size from 1 to 10 centimeters, orbiting our planet. Most of these objects are too small to be effectively tracked from the ground, posing a significant threat to operational satellites. With velocities five times faster than a bullet, even these small objects can cause catastrophic damage upon collision with active satellites. While active satellites are increasingly capable of avoiding collisions with tracked debris objects, there are thousands of large derelict objects that cannot be maneuvered. Moreover, active satellites can fail before being deorbited, adding to the existing population of space debris. A collision between two bus-sized objects would generate tens of thousands of fragments larger than 10 cm and hundreds of thousands of smaller fragments. Such dramatic events can initiate a dangerous cascade effect that exponentially increases the population of space debris.
Space debris impacts an expanding space economy
The consequences of space debris extend beyond the immediate risk of collision. Congested orbits not only make operations more costly due to increased shielding requirements and evasive maneuvers but also jeopardize the long-term benefits we derive from space activities, which cannot be overstated. In recent decades, the space industry has experienced significant growth and expansion, transforming our lives in numerous ways. Satellites have become integral to modern society, enabling global connectivity, navigation, weather monitoring, scientific research, and much more. They provide crucial data for climate change studies, support communication networks in remote regions, and assist in disaster management and response efforts. Moreover, space exploration has inspired humanity while fostering technological advancements and expanding our understanding of the universe. According to the Space Foundation, a nonprofit organization founded in 1983 to advocate for the global space ecosystem, the space economy currently has global revenue of around $469 billion and could reach a trillion dollars by the end of the next decade. This monetary value is only the beginning, as many services such as global positioning and Earth observations are provided free of charge to individual users through government programs.
As the space industry continues to evolve, it opens new opportunities for economic growth and innovation. From satellite constellations for global broadband internet to space tourism ventures and asteroid mining prospects, the potential for commercial activities in space is vast. However, to fully capitalize on these opportunities and ensure the sustainable growth of the space industry, it is imperative to address the challenge of space debris and mitigate its adverse impacts. By doing so, we can safeguard the value and potential of space for current and future generations.
Space debris remediation is a must
Like many environmental issues, the problem of space debris demands a coordinated and multidimensional approach. While efforts have been made to limit the generation of new space debris, it is essential to address the existing pollution to ensure the safe and sustainable utilization of our orbital resources. The de-orbiting of derelict space objects, often referred to as active debris removal (ADR), is a critical tool in mitigating collision risks and preventing the exponential growth of the space debris population. ADR involves the deployment of robotic servicer satellites that capture and manoeuvre defunct objects to lower orbits, where they safely burn up upon re-entry into Earth's atmosphere.
“Although technically challenging, ADR is a necessary solution to preserve the benefits of space activities and protect our valuable space infrastructure,” says Muriel RichardNoca, ClearSpace Chief Technical Officer and Co-founder.
Pioneering initiatives in space debris remediation
Recognizing the urgency and importance of space debris remediation, several organizations and agencies have taken the lead in developing pioneering missions. In Europe, the European Space Agency (ESA) and the UK Space Agency have embarked on ambitious projects to demonstrate the complete value chain of debris removal. The ClearSpace-1 mission mandated by ESA aims to remove a large piece of debris, a Vega Secondary Payload Adapter (VESPA), from Earth's orbit in 2026, showcasing the feasibility of debris removal. ClearSpace, a spin-off from EPFL, the Swiss Federal Institute of Technology in Lausanne, has built a strong industrial consortium to accomplish this trailblazing mission.
Luc Piguet, ClearSpace CEO and Co-founder, says: "ClearSpace's vision is to revolutionize how space missions are conducted, promoting sustainability and driving the circular space economy. Our dedicated engineering teams across multiple countries are working tirelessly to develop groundbreaking technologies for in-orbit servicing applications. With the support of the European Space Agency and esteemed partners like Omega, we are proud to work on the world's first missions to remove debris from orbit with ClearSpace-1 and CLEAR. Our rapid growth and involvement in new servicing missions reflect our commitment to advancing space operations for the benefit of all. Together, we are shaping a brighter future for space exploration."
Similarly, the UK Space Agency has launched its own national space debris removal program aimed at removing two UK-registered derelict objects with a single servicer. It has selected Astroscale and ClearSpace to design missions that will meet this goal and intends to provide further funding to make one removal mission fly in 2026. These initiatives serve as crucial stepping stones toward commercial space debris removal services.
Overcoming technological, legal, and economic challenges
Space debris remediation presents numerous technological, legal, and economic challenges that must be overcome for successful implementation. Capturing derelict objects that have been in space for extended periods requires advanced robotic systems capable of precise and autonomous operations. Servicer satellites need to be equipped with sophisticated sensors and tools to identify, approach, synchronize with, and capture debris objects while accounting for their varying shapes, sizes, tumbling motions, and orbits. Additionally, ensuring the safe disposal of the captured debris requires careful planning to execute reentry or deorbit maneuvers, minimizing the potential for fragments to survive reentry and pose a hazard to assets or people on the ground. Such missions necessitate the development of specific propulsion systems and algorithms that enable precise orbital and attitude maneuvers and the selection of optimal disposal trajectories. As a key step in the development of this debris-removal mission, ClearSpace has designed a four-armed capture system for a robotic satellite servicer, an innovative technology that successfully passed proof-of-concept testing at ESA's technology center in the Netherlands in October 2022.
One of the key legal considerations is the ownership and liability associated with space debris. With a vast number of countries, private companies, and international organizations involved in space activities, determining the parties responsible for debris removal and the allocation of associated costs can be complex. Clear regulations and international agreements need to be established to clarify the legal framework surrounding debris removal missions. This includes defining the rights and obligations of stakeholders involved in the remediation process, specifying liability for any damage caused during capture and disposal operations, and establishing protocols for international cooperation in sharing information and resources. Strengthening existing international space law and developing new legal mechanisms specific to space debris remediation will be essential to provide a solid foundation for these activities and encourage participation from all relevant parties.
Despite these challenges, the push for space debris remediation is gaining momentum. Governments, space agencies, and private companies are investing in research and development, fostering innovation in technologies and techniques that will enable more efficient and cost effective debris removal missions. The progress made in space robotics, artificial intelligence, and miniaturized sensors are opening new possibilities for automated debris capture and removal. Additionally, advancements in on orbit servicing capabilities offer potential synergies with space debris remediation efforts, as the same technologies and infrastructure could be utilized for servicing and maintaining operational satellites, further enhancing the sustainability of space activities.
Conclusion
The proliferation of space debris poses a significant threat to the future of space exploration and satellite-based services. While measures to prevent the generation of new debris are crucial, addressing the existing pollution through space debris remediation is equally essential. Efforts are underway to develop and demonstrate the capabilities required for active debris removal, with pioneering missions and initiatives leading the way. Overcoming technological, legal, and economic challenges and fostering international collaboration will be key to the success of these endeavours. By removing space junk, we can ensure the long-term sustainability of space activities, protect critical space infrastructure, and pave the way for a safer and more prosperous future in space exploration and utilization.
