Three Burn Inertial Upper Stage Optimal Orbit Transfer

摘要

The Inertial Upper Stage (IUS) being developed for use aboard the Space Shuttle is composed of three solid fuel stages plus a satellite payload. One mission of the IUS system is to launch from a shuttle parking orbit and place the satellite in geosynchronous orbit in minimum time. Actual Space Shuttle parking orbit data and IUS characteristics were used in this study to examine the sequential timing and orientation in inertial space of each stage as it is fired while the spacecraft moves along a transfer orbit to geosynchronous orbit. In addition, the sensitivity of the total transfer time and the final orbital state was found as a result of not meeting one or all of the time and orientation parameters. This problem is unique in that it considers an optimal orbit transfer problem involving solid fuel stages of fixed thrust and burn time. Previous work with liquid fuel engines examined orbital transfers with the intent of minimizing the amount of propellant or required velocity change needed to accomplish the transfer. (Author)