A darling of NASA and of the general public, the Kepler Space Telescopes, dedicated to looking at extra-solar planets, may be soon ending its run. A recent hardware failure on the Kepler has led experts to give Kepler just one more year.
Kepler had four reaction wheels, which keep Kepler steady and able to focus unerringly at distant stars and planets. Kepler really needs three wheels to achieve this job, but has four just in case. Earlier, in July, 2012, one of these wheels had broken down, putting engineers slightly on the edge. Kepler, however, continued to function as well as it always did.
On 9th May, engineers found Kepler in automatic safe mode, since something was wrong. To their dismay, they found that one of the three remaining wheels had malfunctioned. Kepler’s days seemed numbered.
Kepler stares at faraway world, shielding its own cameras from the glare of the Sun. However, light from the Sun hits the craft (and, in fact, fuels it) and exerts pressure on it, called radiation pressure. No matter how small this is, this is enough to throw Kepler a bit off its line of sight. And this is where the wheels come in, ensuring that the photons are not the nuisance that they really are.
Engineers are scrambling for ideas to save Kepler. They are trying to use the boosters to compensate for the reaction wheels, but this won’t give the stability that Kepler enjoyed. Its planet watching days may be over.