Back from the dead: Kepler returns


The Kepler spacecraft is back at what it does best, a glitch had occurred that had sent the planet-hunter into an emergency mode. Mission engineers at NASA have managed to repair the vehicle, by a step-by-step process, while it was almost 75 million miles away from the planet Earth. Kepler is in the second stage of its mission, exploring the nearby stars for the signs of alien worlds. When mission scientists attempted to contact the craft on April 7, they found the vehicle had placed itself into a shutdown mode, usually reserved for emergencies. In this state, the solar panels on the vehicle turn to face the sun, as the observatory slowly rotates in space. Following a series of commands, engineers were able to place Kepler into safe mode on April 15.

Controllers have now switched Kepler to a point rest state, at which time the vehicle uses very little fuel, and all the priority is given to communications with controllers. On April 12th, NASA officials were able to successfully download enough information from the Kepler to diagnose the real problem. After that, engineers were able to create series of commands that were designed to switch on non-critical segments of the spacecraft. The rescue plan was first tested on a Kepler simulator. When the plan worked there, the instructions were sent to the Kepler spacecraft. “The recovery started slowly and carefully, as we initially merely tried to understand the situation and recover the systems least likely to have been the cause,” said Charlie Sobeck of the Ames Research Center, managed by NASA. “Over the last day and a half, we’ve begun to turn the corner, by powering on more suspect components. With just one more to go, I expect that we will soon be on the home stretch and picking up speed towards returning to normal science operations.”

Engineers diagnosed the data returned by Kepler, and in order to presume the events that could have led to the vehicle enter the emergency mode. However, fault indicators within the observatory have been designed to be quite sensitive, and it has been possible systems that are overwhelmed by several alarms going off at single time. “The thing to keep in mind is K2 had been quite trouble free and we think that it be trouble free going forward. We don’t believe this signals the end of the mission for Kepler at all,” Sobeck said. Kepler was launched in the year 2009, in order to hunt for planets around the other stars in galaxy. Since that time, it has found more than 1,000 confirmed exoplanets, as well as 3,500 suspected planetary entrants.

This was not that the first time mission engineers had been able to bring the Kepler back from a dead. In 2013, the second of four reaction wheels given out, eliminating navigational ability of the space vehicle. Engineers were able to find a way out to use pressure from the sunlight to guide the observatory. This revitalized mission was known to be K2, and now includes observations of supernovae and other celestial events. While Kepler is now in safe mode, the vehicle allows one more error to take place. However, if second alarm had been signalled while Kepler was in emergency mode, NASA would have lost close to $600 million observatory.