The implementation of cost effective debris protection in unmanned spacecraft

Abstract

Proper characterisation of the survivability of an unmanned spacecraft to debris impact must go beyond just a simple assessment of the probability of penetration. Some penetrative damage may be survivable, particularly if critical internal equipment is arranged judiciously. Consideration of the satellite architecture can be seen as a potentially cost-effective and complementary approach to the more traditional method of adding shielding mass. To quantify the benefits of both strategies, and identify candidate protection solutions for a typical satellite design, a new model called SHIELD has been developed. Competing protection options are evaluated using a survivability metric. Rapid convergence on one or more `good' designs can also be achieved with a built-in genetic algorithm search method. SHIELD's potential as a project support tool is illustrated by applying it to the survivability evaluation of a satellite currently under design. The effectiveness of the genetic algorithm is also demonstrated, but on a more idealised spacecraft design.