NASA’s Kepler space telescope has unexpectedly gone into “Emergency Mode” (EM), its lowest operational mode that is fuel intensive. NASA engineers are working to try to get the probe working normally.
It was discovered Kepler was in trouble during a routine contact on April 7. While in emergency mode Kepler burns more of its declining supply of fuel. To position the spacecraft so it can communicate with Earth, Kepler needs to conserve its fuel.
The spacecraft has yet to execute the turning manoeuvre that is needed to start the much-anticipated phase of its planet hunt. Kepler mission manager Charlie Sobeck of NASA’s Ames Research Center in Moffett Field, California, wrote in a mission update Friday (April 8):
“EM is the lowest operational mode, and is fuel intensive. Recovering from EM is the team’s priority at this time.
“The mission has declared a spacecraft emergency, which provides priority access to ground-based communications at the agency’s Deep Space Network.”
The last regular contact with Kepler occurred on April 4, with the spacecraft being healthy and operating properly at that time, Sobeck added.
The Kepler spacecraft is almost 75 million miles (121 million kilometers) from home, which makes any communication with it slow. Even traveling at the speed of light, it still takes 13 minutes to travel to the spacecraft and back. Sobeck wrote:
“It could take some time to diagnose and fix the problem, because Kepler orbits the sun rather than Earth, and there is thus a significant time delay in communications.”
After finding nearly 5,000 exoplanets, with more than 1,000 of them being confirmed, Kepler had successfully completed its prime mission in 2012. Kepler then began its next mission, called K2, in 2014. While it continued to search for exoplanets, new research opportunities where introduced, such as studying young stars and supernovae.
Kepler finds planets by observing the revealing brightness dips as they eclipse their host stars, the $600 million mission has been exceptionally successful. However, this is not the first time Kepler has been in trouble.
In May 2013, during the second of its four orientation-maintaining, its reaction wheels had failed, which caused the main mission to end early. However, mission managers were able to figure out a way to stabilize Kepler’s position in space by using only two reaction wheels and sunlight pressure to compensate for the loss of the reaction wheels.