Author: Akash Pal, a student at LC2, Faculty of Law, Delhi University
Introduction
Space is big, it’s so big and vast that even with current modern advance space technology, we cannot fully explore it, our current exploration is limited to solar system, exoplanets and deep space but what if I tell you that space is getting crowded now, at least in low-earth orbit because of space junk and debris.
Space debris are defined as all non-functional, man-made objects, including fragments, pieces and elements in low-Earth and it includes discarded rocket stages, defunct satellites and unidentified debris objects and fragments. Man-made space debris dominate over the natural meteoroid environment, except around millimetre sizes.
Main cause of concern is that now space junk is quickly proliferating in low-Earth orbit, or LEO, causing more debris, jeopardizing space research, and posing risks towards space operation such as collisions with active operational satellites.
The Challenge of Space Debris
Space debris orbits the earth at very high speeds in LEO that ranges up to 7 to 8 km/s however the impact speed of debris with another object can exceed that speed and goes up to 15km/s which is insanely high and comparable to travelling speed of bullet and such high speed has some own risks associated with it.
The risk is not limited to only space research but also pose a great threat to humans and countries such as:
Kessler Syndrome: a worst-case scenario in which the density of debris is so high that collisions cause a cascading effect, resulting in an unmanageable debris field that makes near-Earth orbit untenable.
Orbital congestion: that will make difficult to launch and operate new satellites.
Risk of re-entry in earth atmosphere.
Economic loss due to loss of operational satellites because of collision.
Spacecraft damage: collisions pose a serious threat to the lives of astronaut in spacecrafts.
Ground damage: although the possibility of ground damage is very less as most of the times the debris burns up before impacting ground due atmospheric pressure and resistance but in few cases where large pieces of debris could potentially re-enter the Earth’s atmosphere and cause damage on the ground.
Current Mitigation Efforts
IADC (Inter-Agency Space Debris Coordination Committee) Space Debris Mitigation Guidelines
Limit Debris Released during Normal Operations: Design spacecraft and orbital stages in such a way to minimize debris release during normal operations. Assess and verify the long-term impact on the orbital environment.
Minimize the Potential for On-Orbit Break-ups: Prevent break-ups during missions and at the end of missions by depleting stored energy sources like propellants and batteries.
Post Mission Disposal: Manoeuvre spacecraft to safe orbits after mission completion to avoid interference with operational spacecraft. Options include like de-orbiting or relocating to less congested orbits.
Prevention of On-Orbit Collisions: Estimate and limit the probability of accidental collisions with known objects. Consider avoidance manoeuvre if reliable orbital data is available.
Active Debris Removal
Active Debris Removal (ADR) is the process of sending spacecraft to rendezvous with and remove defunct satellites or debris from orbit.
This is mainly focused on Low Earth Orbit (LEO) and Medium Earth Orbit (MEO) where the natural process of orbital decay is slower and thus require ADR.
ADR mainly involves three steps
Identification: identifying space debris or defunct satellites.
Development: development of spacecrafts capable of capturing or de-orbiting the debris.
Execution: executing the mission to safely remove the debris from the orbit.
Proposed Solutions
Ion-Beam Shepherd-Based Methods: This concept involves using a beam of quasi-neutral plasma to impart a propulsive force on space debris, pushing it into disposal orbits. Although promising but it faces challenges like beam divergence, pointing errors, and sputtering. Various studies have shown optimization of the system’s mass, propulsion requirements, and controllability. However, real-time flight data and experimental validation are needed to address issues like plasma plume interaction and the health of the shepherd spacecraft. Despite its potential, the efficiency and practical implementation of this method require more research and testing.
Laser-based methods: for active space debris removal this method involve using high-power lasers to either divert debris from the ground or space. These methods include the Laser Orbital Debris Removal (LODR) system, which is cost-effective and capable of handling both large and small space debris. Technological advances have been made in space-based laser systems, such as the International Coherent Amplification Network (ICAN), which can track and deorbit small-scale debris. Despite their efficiency, challenges remain, including system readiness, target acquisition, and energy consumption. Recent research focuses on optimizing these systems for better performance and addressing practical issues like beam divergence and power supply.
Tether-based methods: it mainly focuses on the use of tethers for active space debris removal. These methods involve attaching tethers to debris to alter or modify their orbits, causing them to re-enter the atmosphere and burn up.
Sail-based methods: involve using large surface fabrics to harness solar radiation pressure (SRP) and atmospheric drag to deorbit debris. These methods include deploying solar sails or drag sails to increase the surface area and reduce the deorbit time of satellites and debris. Key advancements include the development of the KnightSat II system, gossamer deorbiters, and inflatable magnetic sails. These methods are advantageous as they require no external fuel or power, but they are slow and can be difficult to control.
Legal Framework
International Legal Frameworks governing space debris mitigation: key international treaties and agreements, such as the Outer Space Treaty (OST) of 1967, which establishes principles for the exploration and use of outer space, including debris mitigation. moreover, it mentions the Liability Convention and the Registration Convention, which address liability and registration of space objects that indirectly impacts debris mitigation efforts.
The United Nations Committee on the Peaceful Uses of Outer Space (COPUOS) guidelines and principles, which provide best practices for reducing debris generation, managing spacecraft disposal, and enhancing space traffic management to promote sustainable activities in outer space
Indian Legal Framework. includes Indian Space Activities Act (ISAA), which regulates and authorizes space activities in India, including aspects related to debris mitigation and management. There are also many national policies and initiatives that align with global guidelines on space debris management. Despite India’s efforts to comply with international principles, the practical implementation of these regulations poses challenges, particularly in monitoring, tracking, and ensuring compliance with debris mitigation measures
Conclusion
The urgency of addressing space debris cannot be overstated. As in future the population of defunct satellites, rocket stages, and fragments in Earth’s orbit continues to grow, the risk of catastrophic collisions and then the Kessler Syndrome becomes increasingly imminent which poses a great threat towards earth and countries scientific endeavours. Current mitigation efforts, while essential, are insufficient on their own. Active Debris Removal (ADR) methods, such as space lasers, nets, and robotic arms, offer promising solutions but require robust international cooperation and legal frameworks to be effective.
Legal solutions play a pivotal role in ensuring a cleaner cosmic environment. By establishing clear guidelines and fostering global collaboration, we can develop and implement effective ADR strategies. The time to act is now, to safeguard the future of space exploration and protect the vital infrastructure that modern society depends on.
FAQs
1. What is space debris and why is it a problem?
– Answer: Space debris, also known as space junk, consists of defunct satellites, spent rocket stages, and fragments from disintegration, erosion, and collisions. It poses a significant threat to operational satellites, the International Space Station, and astronaut safety due to the high speeds at which debris orbits Earth (up to 7 km/s). Collisions with space debris can create more fragments, leading to a cascading effect known as the Kessler Syndrome, which can render certain orbits unusable.
2. What are the current efforts to mitigate space debris?
– Answer: Current mitigation efforts include compliance with post-mission disposal guidelines, such as deorbiting defunct satellites and rocket stages within 25 years. Additionally, there are measures to design satellites with minimal debris generation and to avoid collisions. However, these efforts are not sufficient, and there is a growing need for active debris removal (ADR) to address the existing population of intact objects in low Earth orbit (LEO).
3. What are some proposed solutions for active debris removal (ADR)?
– Answer: Proposed ADR methods include:
– Space Lasers: Using ground-based or space-based lasers to nudge debris into lower orbits, where it burns up in Earth’s atmosphere.
– Nets and Harpoons: Capturing debris with nets or harpoons and then deorbiting it.
– Robotic Arms: Using robotic arms to grab and remove debris.
– Giant Foam Balls: Enveloping debris in foam balls to increase drag and hasten re-entry into the atmosphere.
These methods face challenges such as high costs and the potential for contributing to space pollution.
4. Why is international cooperation important for space debris removal?
– Answer: Space debris is a global issue that affects all space-faring nations. International cooperation is crucial to establish legal guidelines and frameworks that ensure safe and coordinated debris removal efforts. Collaborative efforts can help share the financial burden, pool technological resources, and create standardized practices to effectively address the problem.
5. What legal frameworks exist for space debris mitigation and removal?
– Answer: The legal framework for space debris mitigation and removal is evolving. Key international treaties, such as the Outer Space Treaty and the Liability Convention, provide a foundation for space activities. However, there is a need for more specific guidelines and regulations to address debris removal. Efforts are underway to develop international agreements and national policies that promote responsible behaviour in space and facilitate active debris removal initiatives.
