Space Debris
Introduction
Since the launch of Sputnik in 1957, the number of satellites orbiting Earth has grown to ~1,400. These satellites underpin modern society—communications, TV, navigation, weather, and defence—contributing to a market worth over $300 billion (£233 billion). Alongside active assets, there are millions of debris fragments: NASA estimates >100 million pieces <1 cm, ~500,000 between 1–10 cm, and ~21,000 larger pieces. Travelling up to 40,000 kph, even a 1 cm fleck of paint can inflict damage equivalent to a 250 kg object at 27 m/s on Earth. The Kessler Syndrome further threatens a cascading growth of debris, potentially rendering orbits unusable for satellites and human exploration, and increasing re-entry risks on Earth.
Task
Propose a solution that removes existing debris, prevents new debris generation, or mitigates current debris risks. You may tackle the whole problem or a focused aspect—multiple complementary solutions are expected. Balance technical feasibility, cost, and long-term sustainability, and account for existing space infrastructure.
Considerations
1. Technology
Address the scale, velocity, and varied size distribution of debris while safeguarding active satellites and crewed assets. Select materials and systems that can survive space environments (thermal cycling, radiation, vacuum). Concepts may include capture, deorbit, drag augmentation, shielding, deflection, or collision-avoidance enablement.
- Which technologies/materials best target low-Earth-orbit debris (e.g., nets, harpoons, tethers, electrodynamic drag sails, lasers)?
- How will you cope with distances, high closing speeds, and a wide size spectrum?
- What engineering hurdles (power, sensing, guidance, durability, precision) must be solved?
2. Infrastructure
Design for safe interaction with existing assets and traffic. Deployment, operations, and end-of-life must be practical within current launch and ground-segment capabilities, and must not worsen the debris environment.
- How does your system integrate with/avoid interfering with active satellites and stations?
- What are the logistics for launch, deployment, tasking, and operations?
- How will you prevent your hardware from becoming debris (fail-safe modes, passivation, deorbit plans)?
3. Market Factors
Define customers and value: governments, defence, insurers, satellite operators, and agencies. Benchmark against competing approaches and articulate performance-per-cost and service models (e.g., debris-removal-as-a-service).
- Who are your stakeholders and buyers, and what KPIs matter to them (risk reduction, premiums, uptime)?
- How does your solution compare on cost, throughput, and reliability?
- How big is the addressable market now and as megaconstellations grow?
4. Safety, Security, and Risks
Ensure mission safety and avoid unintended consequences (fragmentation, conjunctions). Consider cybersecurity for command/control and data links. Plan contingency actions for anomalies.
- What hazards arise during capture/deorbit, and how are they mitigated?
- How do you guarantee the system never increases debris or damages third-party assets?
- What cyber protections and authentication will secure on-orbit control?
5. Project Management Approach
Map R&D, simulation, hardware prototyping, HIL tests, mission design, verification/validation, and flight demonstration. Include gated reviews and risk registers.
- Which methodology (Scrum/Sprints, Agile, Waterfall) fits your development and test flow?
- How will you allocate people, facilities, and budget across phases?
- What are the critical milestones (PDR, CDR, environmental test, demo flight) and success metrics?
6. Costing and Feasibility
Estimate non-recurring engineering, spacecraft builds, launch, operations, and decommissioning. Compare lifecycle cost-effectiveness to alternatives and consider service pricing and financing.
- What are design/build/deploy/operate cost ranges and sensitivities?
- How will maintenance, refuelling, or disposal be handled and funded?
- How does cost per kg removed (or collision risk reduced) compare with other solutions?
7. Sustainability, Ethics, Equality, Diversity, and Inclusion
Maximise durability and responsible end-of-life. Address ethical stewardship of the orbital commons and promote equitable access across nations and communities.
- How does your design minimise environmental footprint and extend operational life?
- What ethical principles govern debris remediation and long-term orbit sustainability?
- How will you include diverse stakeholders and ensure fair, global access to cleaner orbits?
Further Information
- Ratner, P. “How the Kessler Syndrome can end all space exploration …” Big Think (2018). Link
- Khan, M. V. H.; Ntantis, E. L. “Space Debris: Overview and Mitigation Strategies.” H-Space (2024). Link
- Mu, C., et al. “Autonomous spacecraft collision avoidance … safe reinforcement learning.” Aerospace Science and Technology 149 (2024): 109131. Link
- Letizia, F., et al. “Improving the knowledge of the orbital population … monitoring.” Acta Astronautica 223 (2024): 734–740. Link
- Singh, G., et al. “Tracking an untracked space debris … physics informed neural network.” Scientific Reports 14 (2024): 3350. Link