Closing the Sub-Centimeter Gap in Low Earth Orbit Debris Awareness: A Distributed Bistatic CubeSat Radar Concept for Continuous Small-Debris Cataloguing.

Low Earth Orbit holds an estimated one million fragments between one and ten centimeters across. None of them appear in any catalogue. At orbital velocity, a fragment this size carries enough kinetic energy to destroy an operational spacecraft on impact, yet it sits below the detection floor of every ground-based radar and optical sensor running at a useful revisit rate. This paper asks why incremental upgrades to that ground-based architecture, built around a handful of large, fixed sensors, cannot close the gap, then proposes an alternative: a distributed constellation of low-cost CubeSats carrying small bistatic radar transceivers and wide-field optical sensors, cooperating through inter-satellite ranging to detect, triangulate, and catalogue debris from orbit rather than from the ground. Orbital geometry, radar link budget, onboard processing load, and data-fusion architecture are worked through in enough detail to run on hardware already flying on educational and commercial small satellites today. The concept is measured against the present ground-based model on coverage, cost, and resilience, and the paper closes with the specific steps needed to fly a two-satellite proof-of-concept.