In 2009 NASA launched Kepler, one of its most exciting experiments ever. The spacecraft was designed to find earth-sized planets orbiting other stars in the galaxy and has been a huge success in terms of data retrieved. Last year NASA announced that Kepler had found over 1000 confirmed exoplanets in over 400 stellar systems. Sadly, the spacecraft has had several major mechanical failures over the years and this week seems to be in its worst state yet. You think you have it rough when tech breaks down at home? NASA engineers are now trying to fix a broken spacecraft 75 million miles away.
Kepler was able to find exoplanets by watching the brightness of hundreds of thousands of stars. When a planet orbits round its star, the brightness of the star dips as the planet blocks out some of the light reaching Kepler. We can learn a lot about the planet from these dips in light.
In 2012, one of the four reaction wheels broke. The wheels allow Kepler to be pointed in the right direction both for finding exoplanets and also for sending data back to Earth. It soldiered on but another wheel broke in 2013, meaning Kepler was severely restricted and could no longer be used for its original mission. A new mission, K2, used its remaining wheels and thrusters to study habitable planets, supernovae, and other interesting phenomena so that useful data could come back from the spacecraft that costs $18 million per year to keep running.
A new emergency
Engineers at NASA heard back from Kepler on April 4 and everything was good. They contacted it again on April 7 to point it at the centre of the galaxy but something had gone very wrong in the time between. Kepler has entered Emergency Mode (EM), which is particularly problematic because it burns a lot of fuel. Engineers are working desperately to stop EM as soon as possible and save the fuel. NASA has given the Kepler team priority access to its communication network.
Nobody knows why Kepler entered EM but that’s a worry for another day. NASA themselves are in emergency mode as engineers scramble for solutions to fix a spacecraft that’s already damaged and 75 million miles from home. The progress will be painstakingly slow as it takes 13 minutes for signals to travel between Earth and Kepler. Their goal is to deactivate EM to save the fuel essential for its mission.
Kepler has been invaluable and has taught us so much about planets outside our own solar system. It would be a great shame to see it lost and inoperable. Good luck, NASA!
Main image © NASA