NASA has approved the mission K2, also called “Second Light”, for the Kepler space telescope. The funding is available for the next two years and allows to reactivate an astronomical instrument that gave tremendous success as a planet hunter but seemed lost because of a fault at its gyroscopic system that kept its pointing with extreme precision. NASA scientists devised a new way to keep Kepler pointed, albeit with certain limitations, to use it not only as a planet hunter but also for other astronomical research.

In May 2013, a failure was announced to one of the reaction wheels that make up the gyroscopic system that kept pointing the Kepler space telescope with extreme precision. It was the second reaction wheel that failed of the four available and at least three are needed for its proper functioning. Attempts to reactivate one of the two faulty reaction wheels failed so Kepler was parked waiting to decide what to do with it.

The Kepler space telescope’s instruments are working so it would’ve been a real shame to be forced to give up using it. Eventually, NASA scientists devised a brilliant plan to compensate at least in part the availability of only two reaction wheels. The idea is quite simple and consists in using sunlight to stabilize Kepler.

Even light exerts a certain pressure and this can be exploited to help the Kepler space telescope to stabilize its position together with the reaction wheels that are still working. This solution, however, makes it necessary to keep it at a specific position relative to the Sun. The consequence is that the K2 mission will be divided into campaigns, which means periods in which Kepler will be used to observe a certain portion of space.

At the end of last year, some tests were carried out to verify that the plan would work and they were successful. At that point, it was necessary to approve a new mission with funding for its operations, which has now arrived. Kepler will no longer be specifically a planet hunter but will also be used to observe star clusters, stars, galaxies and supernovae.

NASA created an illustration – very large! – that shows how the pressure of sunlight is now being used to balance the Kepler space telescope. The K2 mission is a victory of NASA scientists’ ingenuity as they were able to save a very sophisticated and expensive instrument that now will be used again for scientific research.

[ad name=”eBayUSUKAstronomy”]