Full-sky Astrometric Mapping Explorer: An optical, astrometric survey mission

The Full-sky Astrometric Mapping Explorer (FAME) is a MIDEX class Explorer mission designed to perform an all-sky, astrometric survey with unprecedented accuracy, determining the positions, parallaxes, proper motions, and photometry of 40 million stars. It will create a rigid, astrometric catalog of stars from an input catalog with 5 < m(V) < 15. For bright stars, 5 < m(V) < 9, FAME's goal is to determine positions and parallaxes accurate to < 50 mu as, with proper motion errors < 50 mu as /year. For fainter stars, 9 < m(V) < 15, FAME's goal is to determine positions and parallaxes accurate to < 500 mu as, with proper motion errors < 500 mu as /year. It will also collect photometric data on these 40 million stars in four Sloan DSS colors. FAME uses a single optical telescope to observe two fields of view simultaneously. Both fields of view are imaged onto a single focal plane consisting of 24 CCDs operated in TDI mode. The TDI rate is synchronized with the 40 minute rotation period of the spacecraft. Solar radiation pressure on the Sun shield precesses the rotation axis of the spacecraft with a 20 day period so that FAME will cover the entire sky. FAME will observe continuously over its five year lifetime except during occasional station keeping maneuvers to maintain its position in geosynchronous orbit. FAME is funded and is scheduled to launch in June 2004.