Spacecraft End‐of‐Life Disposal

Abstract

AbstractThere is general recognition that space debris, non‐functioning human‐made objects in Earth orbit, will have long‐term effects on satellite operations. As a result, there are increasing calls for slowing the growth of the debris population by limiting debris released during normal satellite deployment and operations, minimizing on‐orbit explosions and breakups, preventing collisions of space objects, and disposing of space hardware at end‐of‐mission. This chapter discusses the latter option: disposing of hardware, both satellites and launch vehicle stages, at end of mission. Disposal options depend on the object's orbit: for example, objects in or passing through low earth orbits may be disposed by allowing orbits to naturally decay within a fixed time limit (hazards posed by debris surviving such reentries can eliminate this option), and objects in geosynchronous orbits should be moved to a disposal orbit several hundred kilometers above that region. This chapter describes the disposal options available for satellites and launch vehicle stages in each orbit regime. Related topics include: techniques for estimating the hazard posed by reentry of space hardware and designing space hardware to minimize reentry hazards, depletion of energy sources (passivation) prior to end‐of‐life to prevent on‐orbit explosions, and disposal techniques that may be available in the future, such as space tugs, electrodynamic and momentum exchange tethers, and drag‐enhancing devices to speed orbit decay.