OMG! Too Much of Space Junk
Humans are littering space with thousands of satellites, which pose a risk to climate and the environment, space sustainability is the need of the hour .

Most governments boast about their space exploration programmes, but now they are also focusing on clearing the junk it leaves in space and on Earth. The increasing accumulation of space debris — fragments from defunct satellites, spent rocket stages, and other leftover materials — poses a significant threat to the future of space exploration, astrophysical research and human lives on Earth. Space junk has already led to several close calls in recent years (See Box). As a result, several green warriors and researchers have requested the United Nations to include the protection of Earth’s orbit in the UN’s sustainable development goals. Space junk is not only a potential hazard for astronauts, it also endangers vital scientific instruments crucial for our understanding of the universe. Given the global space junk problem, India has already started working towards reducing its space debris through initiatives like the Debris Free Space Mission (DFSM). “The goal is to make all Indian space missions debris-free by 2030,” says an aerospace sustainability researcher privy to the development. The DFSM programme was launched by Somanath S., former Chairman, ISRO, Secretary, DOS during the 42ndAnnual Meet of the InterAgency Space Debris Co-ordination Committee (IADC) in Bengaluru on April 16, 2024.
Growing Menace:Space debris refers to the thousands ofpieces ofdefunct satellites, rocket fragments, and even small bits of leftover debris from previous missions that now orbit the Earth. These fragments, although often tiny, pose a huge danger due to the incredible speed at which they travel — up to 28,000 kilometres per hour. Even a small particle moving at such high velocities can cause significant damage to spacecraft and satellites. The risk of collision with space junk is a growing concern, particularly for spacebased research. Satellites, such as those used for communications, weather monitoring, and scientific observation, are vulnerable to damage from debris. Additionally, the increased number ofprivate and commercial space missions means more objects are being sent into orbit, exacerbating the problem.
Impact on Reserach: Micrometeorites and tiny pieces of debris can easily damage delicate instruments and components, such as solar panels and sensors. A collision with space junk could disable a satellite or telescope, causing mission delays or rendering the equipment unusable. For instance, the Chandra X-ray Observatory, which studies high-energy phenomena such as black holes and neutron stars, is particularly vulnerable to debris that could damage its delicate instruments. Similarly, the James Webb Space Telescope, which will observe distant galaxies and study the origins of the universe, is at risk of facing delays or setbacks due to space junk. Dr. Debarati Chatterjee, an Associate Professor, Chair of LIGO-India Education and Public Outreach InterUniversity Centre for Astronomy and Astrophysics, a theoretical astrophysicist, emphasizes the growing concern for space-based research. “Space debris management is crucial for long-term sustainability in space missions,” she says. she says. “The impact of debris on critical instruments could potentially delay or even halt important astrophysical research.” She highlights how the debris threatens the ability of missions to study compact stars like neutron stars and black holes — objects that are difficult to observe from Earth due to their extreme environments.
Gravitational Wave:The study of gravitational waves, ripples in spacetime caused by massive objects like black holes and neutron stars, is another field at risk from space debris. Gravitational wave detectors, such as LIGO (Laser Interferometer GravitationalWave Observatory), have revolutionized our understanding of the universe. While groundbased detectors like LIGO are not impacted by space junk, future space-based detectors, such as the Laser Interferometer Space Antenna (LISA), could face significant challenges. LISA, which is scheduled for launch in the 2030s, will detect gravitational waves from space. Unlike ground-based detectors, LISA will operate in Earth’s orbit, where space debris is more abundant. Debris in space poses a risk of damaging the spacecraft’s sensitive instruments which rely on precise measurements to detect gravitational waves. Dr. Chatterjee points out that while current detectors like LIGO-India are not affected by space junk, space-based missions such as LISA will need to account for the growing debris problem. “Space debris is an issue that must be addressed to ensure the success of missions like LISA,” she states. “Future gravitational wave detectors will require sophisticated designs to mitigate the risk of damage from debris.”
Collision Risks:Beyond scientific instruments, space junk poses a direct threat to the safety of astronauts working in space. Spacewalks, which are essential for repairing satellites and conducting maintenance on the International Space Station (ISS), expose astronauts to the dangers of flying debris. In 2016, astronaut Timothy Kopra was nearly hit by a piece of space debris while on a spacewalk to repair the ISS. The debris came within 20 feet of the astronaut, highlighting the very real risks that space junk poses to human space exploration. Dr. Chatterjee notes that “micrometeorites or debris collisions pose severe threats not only to satellites but also to astronauts performing repairs in space. The risk of collision with space debris needs to be mitigated to ensure both the safety of astronauts and the continuation of vital research.”
Mitigating Space Debris:Addressing space debris requires a combination of strategies. One of the most critical steps is improving space situational awareness. Agencies like NASA and ISRO (Indian Space Research Organisation) are developing systems to track debris and predict potential collisions with operational satellites. This technology allows space agencies to adjust the orbits of satellites to avoid collisions with space junk. Dr. Chatterjee highlights the importance of initiatives like ISRO’s Project Netra, which is designed to track and monitor debris that could pose a threat to Indian satellites. “Space debris management efforts such as ISRO’s Project Netra are vital to ensure the continued success of Indian space missions,” she explains. “These initiatives help track potential threats and allow space agencies to take quick action to avoid catastrophic collisions.” In addition to tracking debris, scientists are also exploring active debris removal technologies. Techniques such as using robotic arms to capture debris or employing spacecraft designed to push satellites out of orbit could help reduce the amount of space junk in Earth's orbit.
The Path Forward:Space debris is a global problem. Dr. Chatterjee stresses the need for a collective approach: “Global collaboration is key to managing the growing threat of space debris. Space-based gravitational wave missions, such as LISA, require international cooperation to ensure that the technology is designed to withstand the risks posed by space junk. Only through collaboration can we develop comprehensive solutions to mitigate these threats.” The future of space exploration depends on our ability to effectively manage space debris. As Dr. Chatterjee concludes, “Managing space debris is not just about protecting our current missions, but also safeguarding the future of space exploration and astrophysics.”