The MOST satellite - successfully launched on 30 June 2003 into its 820-km polar orbit - is nearing the end of its commissioning phase and begins normal science operations on 20 December. Its first official Primary Science Target will be Procyon. All the MOST systems are functioning well, and have proved robust to the radiation environment, even during some of the most intense flares on record. In particular, the Attitude Control System is working beautifully, achieving fine pointing with rms errors of about 3 arcsec. This is well below the requirement, and is unprecedented for a space platform of such small inertia.
During the last three months of commissioning, MOST collected trial photometry on three targets - a known beta Cephei pulsator, an active solar-type star, and Aldebaran. These test runs have yielded the most complete and precise photometric coverages of any stars in history; the second run covered 29 days with a duty cycle of 97%, reaching a noise level of 6 micromag at frequencies above 1 mHz, on a star of V ~ 5. (For comparison, coordinated ground-based campaigns like the Whole Earth Telescope obtain a duty cycle of about 30-40% in a month, with noise levels of about 100 micromag at high frequencies.)