Mission design and trajectory analysis for inspection of a host spacecraft by a microsatellite

Abstract

The trajectory analysis and mission design for inspection of a host spacecraft by a microsatellite is motivated by the current developments in designing and building prototypes of a microsatellite inspector vehicle. Two different, mission scenarios are covered in this thesis - a host spacecraft in orbit about Earth and in deep space. Some of the key factors that affect the design of an inspection mission are presented and discussed. For the Earth orbiting case, the range of available trajectories - natural and forced - is analyzed using the solution to the Clohessy-Wiltshire (CW) differential equations. Utilizing the natural dynamics for inspection minimizes fuel costs, while still providing excellent opportunities to inspect and image the surface of the host spacecraft. The accessible natural motions are compiled to form a toolset, which may be employed in planning an inspection mission. A baseline mission concept for a microsatellite inspector is presented in this thesis. The mission is composed of four primary modes: deployment mode, global inspection mode, point inspection mode, and disposal mode. Some figures of merit that may be used to rate the success of the inspection mission are also presented.

(cont.) A simulation of the baseline mission concept for the Earth orbiting scenario is developed from the trajectory toolset. The hardware simulation is based on the current microinspector hardware developments at the Jet Propulsion Laboratory. Through the figures of merit, the quality of the inspection mission is shown to be excellent, when the natural dynamics are utilized for trajectory design. The baseline inspection mission is also extended to the deep space case.