Location
Howard Johnson Plaza-Hotel, Atlantis/Discovery Rooms
Start Date
22-4-1992 2:00 PM
Description
This paper addresses the dimensional stability of a Nav Base for the Space Station Attitude Determination System. Specifically the methods of evaluating and controlling the thermally induced internal and external forces are discussed.
Space Station Freedom must "know" it's orientation at all times if it is to accurately point sensors and telescopes. Knowledge of orientation is initially acquired through the Star Trackers (ST), then maintained with redundant combinations of the three Inertial Sensor Assemblies (ISA) and two Star Trackers. Only one ISA and one ST are required to determine attitude, but multiple units are used for redundancy and fault tolerance. The ISAs are built by Honeywell and each contains three ring laser gyros to sense rotation in inertial space. Three ISAs and two STs are mounted on a navigation base and shielded with a Whipple type micrometeoroid and orbital debris shield (MMOD).
Paper Session II-A - Dimensional Stability of the Attitude Reference Assembly on Space Station Freedom
Howard Johnson Plaza-Hotel, Atlantis/Discovery Rooms
This paper addresses the dimensional stability of a Nav Base for the Space Station Attitude Determination System. Specifically the methods of evaluating and controlling the thermally induced internal and external forces are discussed.
Space Station Freedom must "know" it's orientation at all times if it is to accurately point sensors and telescopes. Knowledge of orientation is initially acquired through the Star Trackers (ST), then maintained with redundant combinations of the three Inertial Sensor Assemblies (ISA) and two Star Trackers. Only one ISA and one ST are required to determine attitude, but multiple units are used for redundancy and fault tolerance. The ISAs are built by Honeywell and each contains three ring laser gyros to sense rotation in inertial space. Three ISAs and two STs are mounted on a navigation base and shielded with a Whipple type micrometeoroid and orbital debris shield (MMOD).
