NASA Kepler Mission Manager Update 29 May 2009

Kepler remains safe and stable in its “drift-away” heliocentric orbit. The spacecraft is over 8.4 million kilometers from Earth. Kepler has been collecting science data since 12 May. The operations team has had nearly daily contacts using the Deep Space Network to check the spacecraft health. Science data collection is, by design, a very quiet period as the scientists want the spacecraft as stable as possible. Other than the continual collection of science data with Kepler’s photometer, the only activities that occur on the spacecraft, on a regular basis, are reaction wheel desaturations. These desaturations occur about every 3 days.

The orientation of the spacecraft (keeping the telescope pointed at the science field of view) is controlled by reaction wheels which slowly spin up to counter pressure from solar wind. Before any given wheels spin too fast, thrusters are fired to negate the momentum imparted to the spacecraft from the spin-up of the reaction wheels. The reaction wheel speeds are returned to near-zero, and the cycle begins again. We have loaded a command sequence on-board the spacecraft to execute these desaturations.

Meanwhile, scientists at NASA Ames Research Center are continuing their analysis of the instrument calibration data taken during Kepler’s commissioning phase. The data are of very high quality and the scientists are very pleased with the precision of the data. Hundreds of eclipsing binaries and variable stars were seen in this data.