Everyone can get a second chance, even broken space telescopes. Kepler, the planet hunting telescope, suffered a critical malfunction to its stabilizing system in May 2013. It seemed it was the end for the mission, but thanks to the clever men and women at mission control, they managed to reconfigure the probe and keep the search for exoplanets going.
This second phase, called K2, discovered its first exoplanet at the end of 2014, and this week it was announced at the 227th American Astronomical Society Meeting that 100 new exoplanets have now been discovered.
K2 campaigns run for about 80 days at a time, focusing on a particular patch of the sky, with five campaigns having run so far. "This is a validation of the whole K2 program's ability to find large numbers of true, bona fide planets," Ian Crossfield, an astronomer at the University of Arizona, said when presenting the results, as reported by Space.com.
Kepler has observed 60,000 stars and found 7,000 transit-like signals since it was restarted. The telescope uses the “transit method” to discover new planets. The spacecraft is sensitive enough to detect small dips in the brightness of stars and if the dips are repeated with regularity, that is an indication that a planet is orbiting that object.
This method requires extremely precise pointing; thus, the spacecraft had four stabilizing reaction wheels. Kepler only needed three to function so it was not a huge issue when one stopped functioning three years into the mission. When the second stopped working almost a year later, the situation seemed dire.
Luckily they were able to come up with a clever solution. Photons, particles of light, can apply a force to an object. This phenomenon, called radiation pressure, together with the other two stabilizers, was used to keep the telescope in position.
Kepler has been the most prolific planet-hunting mission to date, discovering over 1,000 exoplanets, and it looks like it will be able to see many more in the years to come.