Are there habitable planets, like Earth, orbiting their own sun-like stars far out in space? Five years ago, NASA launched the Kepler Space Telescope in hopes of finding out. Four exciting years of near-monthly transmissions followed, a stream of data and photos giving tantalizing views and clues.
Alas, having identified 931 exoplanets – including a few perhaps capable of being inhabited – Keplers extended mission had to be scrubbed last summer. The fault was not in the stars, but in bearings or housings in some of the vessels four gyroscope-like reaction wheels. At least three of the four fast-spinning, metal reaction wheels are needed to precisely point the $600 million spacecraft for reliable scientific data collection – and two of them no longer work.