This report describes a program for the development of an attitude control and stationkeeping subsystem which uses an electrically heated ammonia propulsion system. The objective of the program was to demonstrate the operation of a high performance ammonia thruster and a zero-gravity ammonia feed system in response to the stimulus of control electronics typical of future military spacecraft. A mission analysis was performed and a three-axis stabilized, 2000-pound, synchronous altitude spacecraft was selected. A survey of several competitive control electronics concepts resulted in the selection of a pulse ratio modulation approach. A three-axis design was prepared, and a single-axis control electronics unit was fabricated. A four-nozzle thruster was developed. A feed system capable of delivering only vapor phase ammonia to the thruster in a zero gravity environment was developed. The single-axis control electronics, a thruster and a feed system were integrated for a one month closed-loop test. The system was subjected to acquisition, limit cycle, stationkeeping, and reacquisition modes of operation. (Author)


    Zugriff

    Zugriff über TIB

    Verfügbarkeit in meiner Bibliothek prüfen


    Exportieren, teilen und zitieren