A New Orbital Debris Reference Model

Abstract

This paper presents a new orbital debris environment model (CODRM-97). It includes the objects with a mass ≥ 1 mg produced by international space launches and operations, 140 energetic breakups and 16 liquid metal coolant leaks from nuclear-powered spacecraft. Each fragmentation or leakage was simulated with the most appropriate models and parameters, and the resulting debris clouds were propagated, including all the significant orbital perturbations, to the chosen reference epoch (January 1, 1997). At this point, the particles still in orbit were merged with the cataloged objects present in space at the same time. In total, more than 65 million particles with a mass ≥ 1 mg were generated during the simulations and more than 52 million were found to be still in orbit at the reference epoch. Preliminary comparisons with the measurements available below 1000 km seem to indicate that the CODRM-97 predictions come short by a factor of two for debris with diameters close to 1 cm and by an order of magnitude for particles with diameters approaching 1 mm. This deficiency might reflect, in part, an intrinsic inadequacy of the breakup models adopted, but probably suggests the presence in space of additional debris sources, not yet included in CODRM-97.