A Friday story in National Geographic reports that NASA has found a way to restart the Kepler space telescope’s planet hunting mission. Kepler was thought to have been crippled by the failure of two of its gyroscopic steering wheels. This failure prevented the Kepler from being pointed accurately at any particular star in three dimensions.
NASA’s workaround consists of using the pressure of solar wind to stabilize the space telescope and keep it pointed in the right direction. The space agency describes it as the equivalent of balancing a pencil on the tip of one’s finger. This would allow the telescope to continue its planet hunting campaign in about 83 day increments four and a half time per orbit around the sun. Between those times the Kepler has to be rotated to keep the Sun’s light from entering the telescope.
NASA has authorized the payment of $20 million for the effort. It will be a two year planet hunting campaign dubbed “K2.” It will focus on planets orbiting red dwarf stars and very bright stars with a view for follow up observations by other telescopes.
Kepler, which cost $600 million, was launched in 2009. It is one of the most successful missions in NASA’s history, having discovered 962 extrasolar planets, half of all that have been discovered. One recent discovery was an Earth-like planet orbiting in the habitability zone of its star where liquid water and hence life could exist.
Kepler does its work by noting the dimming of its target star as a planet or planets pass between the star and the telescope. Scientists are then able to note both the approximate sizes of the planets and their distance from their host stars. Using this method Kepler has been able to discover planets ranging from huge gas giants, some of them orbiting close to their stars, to “super Earths,” Earth-like planets that are larger than Earth but still might contain life.