Navigating the Growing Challenge of Space Debris: Initiatives and Innovations
Space, often perceived as an infinite void, is increasingly becoming crowded with the growing deployment of satellites and the accumulating menace of space debris. Euroconsult, a satellite think-tank, projects that an average of 2,800 satellites will be launched annually from 2023 to 2032, exacerbating congestion issues, particularly in low Earth orbits (LEO). As satellites continue to fill these orbits, concerns about space debris, including decommissioned satellites and remnants from failed missions, are escalating. The European Space Agency (ESA) estimates that there are over 11,000 tons of space debris currently in Earth's orbits, posing a threat to operational satellites and future space missions.
The Challenge of Space Debris
The increasing density of satellites and the rising volume of space debris raise critical challenges. Euroconsult warns that collisions between satellites and space debris are likely to double, leading to more debris and the potential for costly and unplanned satellite maneuvers. In low Earth orbits, where satellites for communication and coverage are strategically placed, the congestion is becoming particularly concerning. If left unaddressed, the growing menace of space debris could disrupt deep space communications and render LEO impractical for satellite constellations.
Global Initiatives for Space Sustainability
Recognizing the urgent need to tackle the space debris challenge, various international initiatives and research programs have been launched. The Earth-Space Sustainability Initiative (ESSI), launched by the U.K. Space Agency in June 2023, aims to bring together industry, academia, states, international organizations, and financial and insurance communities. ESSI seeks to ensure that space continues to support environmental, economic, and scientific interests. Over 130 companies and research organizations have endorsed ESSI's Charter of Principles for Space Sustainability.
The European Space Agency's (ESA) Zero Debris Charter, also introduced in 2023, aims to establish global consensus on space sustainability. It intends to define ambitious and measurable targets for space debris reduction and remediation by 2030. In a notable move, the U.S. Federal Communications Commission (FCC) imposed the first global fine for space littering in October 2023. Dish Network, a U.S. media operator, faced a $150,000 (€137,000) penalty for improperly de-orbiting its EchoStar-7 satellite due to a lack of control.
EU and U.K. Space Debris Removal Operations
The European Union (EU) and the U.K. are actively engaged in space debris removal operations to address the imminent threat. Stella Tkatchova, the European Innovation Council's Space Systems and Technologies Program Director, emphasized the critical need for space debris relief, remediation, and the reuse of orbital assets. According to Tkatchova, ESA's categorization of space debris includes over 11,000 tons of total mass in Earth's orbits. Of the 11,330 satellites in orbit, approximately 6,718 are functional, while the rest contribute to the debris.
Tkatchova highlighted the alarming presence of micro-debris objects, estimated to be over 130 million items, in the 1 mm to 1 cm size range. As satellite deployments, especially for communications, continue to increase, LEO is becoming the most polluted orbit. Addressing this challenge, Tkatchova noted that air drag, the force that eventually pulls a non-functional satellite out of orbit for atmospheric destruction, takes approximately 100 to 150 years for satellites in LEO (500 km to 800 km above Earth).
Consequences of Inaction
The growing volume of space debris is not only a theoretical concern; it is already impacting commercial satellite services. Satellite operators now need to actively track space debris to ensure the safety of their assets. SpaceX, for instance, reported conducting over 25,000 maneuvers of its Starlink constellation between December 1, 2022, and May 31, 2023, to avoid potential collisions. Such avoidance maneuvers will become more frequent as space debris continues to accumulate, requiring satellites to carry more fuel for their operational lifespan.
Innovations in de-orbiting technologies, such as tethers, space-based lasers, and solar sails, may offer solutions to reduce space debris and decrease reliance on chemical propulsion. However, these advancements come with their own set of challenges, including technical design complexities and considerations for radiation and electrostatic discharge (ESD).
Technical Design Challenges in Space Debris Removal
Two companies actively involved in dynamic space debris removal missions are Astroscale and ClearSpace. Astroscale's ELSA-M project targets satellites with a standardized docking plate for efficient capture. Jamie Lloyd, Astroscale's Electrical Assembly Manager, explained the challenges in the capture process, which involves using cameras and LiDAR cameras for precise location identification. Astroscale's approach focuses on slow, controlled approaches to assess the condition of the targeted satellite.
Rory Holmes, ClearSpace U.K.'s Managing Director, highlighted the inherent challenges in designing electronics for space systems, which must withstand extreme conditions such as vibrations during launch, temperature fluctuations, radiation