Kepler has been performing well and has been making science observations since recovery from safe mode on Jan. 27, 2013. Last January the flight team placed the observatory in a precautionary wheel rest safe mode. The next monthly data download from the spacecraft is planned for March 6-7.
The flight operations team is monitoring the reaction wheel friction levels during semi-weekly contacts using NASA’s Deep Space Network. The reaction wheels are used to point the spacecraft, maintaining it’s attitude control. Preliminary indications suggest that reaction wheel #4 continues to exhibit higher levels of friction after the wheel rest operation. If the levels are stable but higher the wheel will continue to functioning. If current spikes start to happen or more current is needed to drive the wheel that could indicate the wheel is failing and this would be very bad news. The spacecraft has already lost one reaction wheel and cannot continue observations with only two wheels. The good news is that it has already executed it’s primary mission and is now in an extended mission. Any new findings are essentially above and beyond what had been planed and are a bonus. In March high rate data of the wheel friction levels will be returned from the on-board recorder and the team will be able to perform a more thorough analysis.
March 6 is the fourth anniversary of the Kepler launch. Through the first 22 months of science operations. Kepler has made many ground breaking discoveries including the recent discovery of a planet which is the size of Earths Moon and an Earth sized planet close to us. Lets hope the reaction wheel continues to work for a long time!