Hazards at GEO: The Space Debris population in the vicinity of the GEO belt and mitigation of its impact on commercial satellites

摘要

Increasingly, attention is being paid to the threat to commercial satellite operations in the Geostationary Earth Orbit (GEO) ring from orbital debris or uncooperative/uncontrolled neighboring objects. In addition to the population of inoperative satellites that were not removed from the GEO ring to a "graveyard" orbit at their end-of-life, optical surveys have identified a class of high area-to-mass ratio (HAMR) objects in the vicinity of the GEO ring. The exact origin and nature of these objects are unknown, and their proximity to the GEO belt poses a hazard to active GEO satellites. The prevalent conjecture is that many of these objects may be parts of derelict spacecraft in 'graveyard' orbits above the GEO ring. Due to their high area-to-mass ratios and unknown attitude dynamics and material characteristics, solar radiation pressure (SRP) perturbs their orbits in ways that makes it difficult to predict their orbital trajectories over periods of time exceeding a week or less, yet the perturbed orbits continue to pass through the GEO belt. To ensure safer space operations in GEO, several commercial satellite owners and operators have joined to create the Space Data Association (SDA), to share information about their spacecraft positions amongst the SDA membership. However, orbital information on non-functioning satellites and space debris in general is not available from within the SDA. Publicly available information is often incomplete and of limited accuracy. We have been conducting a research and development program aimed at detecting space debris and increasing the orbital knowledge of space objects in the GEO ring, to support owners and operators of commercial geosynchronous satellites. We describe our methods, our objectives, and our progress to date.