Radar and Optical Characterization of an Anomalous Orbital Debris Population

Abstract

Analysis of orbital debris data collected by the Haystack radar have shown an anomalously high concentration of debris between the altitudes of 800 and 1000 km. Indications from the Haystack data are that the debris range in size from 8 mm to 2 cm and that they are spherical in shape. Previous work by NASA researchers has shown the likely origin to be the leaking of liquid coolant from the nuclear power sources of a now defunct Soviet spacebased series of ocean surveillance satellites. We report on a project at Massachusetts Institute of Technology’s Lincoln Laboratory to detect, track, and characterize a small sample of the anomalousdebris using ground-based radars and telescopes. Our goal was to provide evidence supporting or refuting the NASA conclusions. We have determined that the size, shape, density, and surface properties of the debris are consistent with the hypothesis that it is liquid, eutectic sodium–potassium coolant like that used in the Soviet satellites. The techniques used to detect and track the debris are discussed. The radar and optical data used to characterize the debris are also presented.