A new guidance method for a DeltaV and re-entry constrained orbit transfer problem

Abstract

This thesis proposes a spacecraft guidance system designed for a unique class of orbit transfer problems. It considers a vehicle that undertakes a maneuver with the objective of precisely flying through a point in space at a particular time. The spacecraft must automatically determine a transfer orbit that will take it from a circular, low-earth parking orbit to a velocity-unconstrained rendezvous with a Keplerian trajectory. A constraint exists that both the final transfer orbit and the ultimate paths of any additional stages must lead rapidly to atmospheric reentry, typically within one revolution. Constrained to a fixed [delta]V resulting from a two stage thrust profile, the spacecraft must execute a burn maneuver that can effectively dissipate energy to place it on a transfer orbit with previously unknown velocity requirements. Finally, the guidance strategy should be robust to the uncertainties typically encountered in real spacecraft orbit transfer problems. In order to meet these constraints, this thesis first develops new analytic analysis of the relationship between reentry, perigee, and [delta]V. Next, a framework is developed for selecting a favorable transfer orbit while considering the various hard and soft constraints in the problem. Following transfer orbit selection, a plane of maneuver is calculated that maximizes likelihood of first stage reentry. Then traditional guidance strategies are adapted to the problem and hypothetical spacecraft design to produce a closed loop guidance solution. Results are presented that demonstrate the effectiveness of the new method.