A model for the evolution of on-orbit manmade debris environment

Man-made debris in low-Earth orbit (LEO) and the conduct of operations/procedures which leave debris in orbit are discussed. With continued deposition and larger vehicles and longer times on orbit for LEO operations, the probability of collisions between such vehicles and some member of the debris population becomes large. Because the collisions will occur at very large relative speeds, a small object which would not normally be considered a hazard might pose a lethal threat to an operating spacecraft. Future debris states must be deduced from an evaluation of many models using a Monte Carlo method for future deposition events. A model for the population evolution is presented and results of model calculations are discussed. Contributions to the population which may be expected to arise from on-orbit collisions and explosions are examined. Results are presented as models for future space usage as an extrapolation of usage in the past, for an era of enhanced space usage, and for an era in which antisatellite tests provide a debris contribution.