Here is a summary of the key points from the paper:
Introduction
- Society’s reliance on space assets has grown significantly, making threats to those assets a major concern
- As of 2020, there were about 5,500 satellites in space but only ~2,300 functioning, leaving ~3,200 defunct satellites and debris orbiting Earth
- Space debris poses a threat of collisions that can have catastrophic consequences and trigger a chain reaction of increasing debris
Key Challenges
Surveillance and Tracking
- Tracking smaller debris down to cm sizes to provide collision warnings and enable avoidance maneuvers
- Improving orbit determination and propagation to enable reliable conjunction predictions
Regulations
- Current voluntary guidelines have failed to prevent anti-satellite weapon testing that produces debris
- Lack of enforceable regulations is a key challenge
Mitigation Strategies
- Guidelines exist for passive mitigation like deorbiting satellites after 25 years
- Active debris removal (ADR) missions are needed to remove large defunct satellites and reduce collision risk
- Low-cost ADR approaches have been demonstrated but further technology development is needed
Planetary Protection
- Developing strategies to deflect dangerous near-Earth objects if they threaten impact
- Improved international coordination and development/testing of deflection methodologies is needed
In summary, key challenges span political, regulatory, and technical realms. Progress requires international collaboration on enforceable guidelines, advanced tracking/modeling capabilities, investment in mitigation technologies like ADR, and continued research into deflection strategies.