Design Considerations for the ORION Satellite: Structure, Propulsion and Attitude Control Subsystems for a Small, General Purpose Spacecraft.

A general purpose satellite ORION has been designed which will launch from the Space Shuttle using a NASA Get-Away-Special GAS canister. The design is based on the use of a new extended GAS canister and a low profile launch mechanism. The satellite is also configured to launch as a dedicated payload on SCOUT or commercial expendable launch vehicles. The satellite is cylindrical, measuring 19 inches in diameter and 35 inches long. The maximum spacecraft mass is 250 pounds, of which 32 pounds are nominally dedicated to user payloads. The remaining 218 pounds encompass the satellite structure and support elements, which include a hydrazine propulsion subsystem and a spin stabilized attitude control subsystem. The propulsion subsystem provides sufficient impulse to enable circular orbits as high as 835 nm or elliptic orbits with apogees at 2200 nm, leaving a nominal shuttle orbit of 135 nm. Four stabilizing booms or active nutation control techniques are employed for spin stabilization about the longitudinal axis of the spacecraft. Attitude control accuracies on the order of 1 deg are attainable for a total mission duration of 90 days to 3 years. Total satellite cost is 1.5 million. The thesis outlines the history of general purpose spacecraft, the ORION design criteria, and the design of the major subsystems.