Accession Number : ADA329069

Title :   Automated Station-Keeping for Satellite Constellations.

Descriptive Note : Master's thesis,

Corporate Author : AIR FORCE INST OF TECH WRIGHT-PATTERSON AFB OH

Personal Author(s) : Shah, Naresh H.

PDF Url : ADA329069

Report Date : 08 SEP 1997

Pagination or Media Count : 365

Abstract : The on-orbit control of future communications satellite constellations poses a challenge greater than the sum of the challenges of controlling each component satellite. New approaches are required which result in viable control systems that are flexible, reliable, and efficient. These approaches must also have the capability to derive control commands targeted at maintaining constellation-level metrics, and not just individual satellite positions and velocities. In addition, a certain level of autonomy is desired in order to minimize ground station communication and activity, and to allow for quick, responsive solutions to on-orbit failures. This work develops and tests a new methodology for the automated station-keeping of satellite constellations. Three conventional station-keeping strategies are proposed and studied, with the use of a constellation station-keeping simulation, for their ability to address the requirements of satellite constellations. In addition, three Lyapunov non-linear control strategies are developed mathematically. Finally, three sets of simulations are conducted to analyze the control and coverage characteristics of the Ellipso constellation. The Automated Station- Keeping Simulator (ASKS), created for this project, combines an optimal n-impulse rendezvous element to provide automated station-keeping for a constellation of satellites using realistic satellite dynamics calculations on a distributed network of workstations.

Descriptors :   *CONTROL SYSTEMS, *AUTOMATION, *ARTIFICIAL SATELLITES, *STATIONKEEPING, VELOCITY, SIMULATION, ORBITS, METHODOLOGY, COMPUTATIONS, STRATEGY, DYNAMICS, THESES, COMMUNICATION AND RADIO SYSTEMS, TARGETING, COMMUNICATION SATELLITES, GROUND STATIONS, CONSTELLATIONS.

Subject Categories : Space Navigation and Guidance
      Unmanned Spacecraft

Distribution Statement : APPROVED FOR PUBLIC RELEASE