The MOST Microsatellite Mission: Canada\u27s First Space Telescope

The MOST (Microvariability and Oscillations of STars) astronomy mission has been chosen by the Canadian Space Agency\u27s Small Payloads Program to be Canada\u27s first space science microsatellite, and is currently planned for launch in late 2001. The MOST science team will use the MOST satellite to conduct long-duration stellar photometry observations in space. A major science goal is to set a lower limit on the age of several nearby metal-poor sub-dwarf stars, which may in turn allow a lower limit to be set on the age of the Universe. To make these measurements, MOST will incorporate a small (15 cm aperture), high-photometric-precision optical telescope to be developed by UBC. The MOST bus and ground stations are being developed by Dynacon and the University of Toronto, in collaboration with AMSAT Canada. Several of the bus subsystems are based on similar designs that have been flown on past AMSAT microsatellites. However, the MOST attitude control system is unusual for a microsatellite, requiring highly-accurate (\u3c 30 arc-seconds) three-axis inertially-fixed stabilization, far better than can be achieved using the gravity-gradient boom stabilization approach typical of many past microsatellites. Dynacon will provide the MOST ACS, based on its Miniature Reaction Wheel (MRW) and High Performance Attitude Control (HPAC) products. MOST\u27s HPAC capability will enable it to be one of the first operational space science microsatellites