Planet-hunting scope beyond repair
Nasa is calling off all attempts to fix its crippled Kepler space telescope - but it is not quite ready to call it quits on the robotic planet hunter.
Officials said they were looking at what science might be salvaged by using what remains of the broken spacecraft.
The 600 million US dollar mission has been in trouble since May, unable to point with precision at faraway stars in its quest for other planets.
That is when a critical second wheel failed on the spacecraft. The first of four gyroscope wheels broke in 2012. At least three are needed for accurate pointing.
Since its launch in 2009, Kepler has confirmed 135 planets outside our solar system. And it has identified more than 3,500 candidate planets.
Kepler's unprecedented job was to track down other Earths.