Case Study of Upper-Stage Disposal for Geosynchronous Debris Mitigation

Abstract

Debris mitigation guidelines and directives specify that geosynchronous satellites and their corresponding upper stages be disposed at end of life in a graveyard zone above the densely populated geosynchronous ring. Although modern satellites often can comply without significant mission degradation, upper stages generally are not designed in a manner that permits easy compliance. This case study analyzed the options available to a typical modern upper stage for either complying with disposal guidelines or for reducing debris risk when compliance cannot be achieved. Results of the study showed that even upper stages incapable of moving to the recommended disposal orbit 300 km above synchronous altitude can still perform significant geosynchronous debris mitigation via proper selection of their blowdown/depletion procedure.