NASA revives Kepler satellite via ‘trick’

NASA has come up with a plan to make the Kepler space telescope functional again. The satellite was damaged some time ago and could no longer keep its balance. NASA is now going to stabilize Kepler by using the sun as the third gyroscopic flywheel.

The new mission for Kepler has been approved, NASA writes on its website. The K2 mission allows the space telescope to continue what it was doing before: searching for exoplanets. Kepler was launched in 2009 and put into orbit around the sun. So far, Kepler has contributed to the discovery of 962 exoplanets. Because a lot of data still needs to be analysed, this number is likely to rise significantly.

Kepler was damaged beyond repair last year when a second of a total of four gyroscopic flywheels broke. Those flywheels were needed to compensate for the pressure the sun’s photons exert on Kepler. With only two of these flywheels left, the satellite could no longer maintain its balance. NASA tried to fix Kepler but eventually decided to stop. As a result, the search for planets seemed to be coming to an end.

In order to still be able to use the space telescope in the search for exoplanets, NASA has devised a trick. Kepler is positioned in the K2 mission in such a way that the photons from the sun hit the satellite on an edge where two solar panels meet. The pressure is therefore distributed evenly over the surface of the satellite, so that the two still working flywheels are sufficient to keep the whole stable.

To achieve that stable position, Kepler’s orientation must be nearly parallel to its orbit around the sun, meaning the telescope will be pointed at a different part of the universe. With the new method, a piece in the universe can be looked at for up to 83 days, after which Kepler has to be rotated to prevent sunlight from shining in. There is funding for the K2 mission for two years.