by Jim Fanson, Kepler, JPL Project Manager
Kepler Mission Manager Report
Kepler's science instrument, called a photometer, was powered on by flight controllers and will be calibrated over the next several weeks. A dust cover remains closed over the front of the photometer so that Kepler's first images will be dark. The dark images help engineers characterize the noise in the instrument's electronics.
The spacecraft's powerful Ka-band radio transmitter was powered on and the vehicle was maneuvered to point its high-gain antenna toward Earth for testing. The primary set of reaction control thrusters was fired for the first time to zero out the small amount of angular momentum that, due to pressure from the sun's intense light, has built up in Kepler's reaction wheels. The reaction wheels are spinning masses used to control the orientation of the vehicle