Kepler space telescope overcomes latest challenge
By
Frank Konkel
With three of its four reaction wheels working, the scope can still be positioned with adequate precision, NASA says.
Artists's rendering of the Kepler space telescope in orbit. (NASA image)
Three wheels won't get your car very far, but three is apparently good enough for NASA's $550 million planet-finding Kepler telescope. The three functioning reaction wheels – the space telescope has four in all – provide enough precision to look for planets outside our solar system, making NASA's latest mission update potentially great news for the space agency.
The July 24 update, authored by Kepler Mission Manager Roger Hunter, states that initial exploratory recovery tests show one of Kepler's two failed reaction wheels responded properly to commands from NASA, spinning in both directions. The wheels control the telescope's position in space.
The craft was operating fine with three wheels until a second malfunctioned in May. The wheel responded to NASA commands to spin counterclockwise, but not clockwise. The tests began July 18.
In the update, Hunter said friction appeared to play a role in issues with the second failed reaction wheel, but added that engineers will take some time before deciding what to do.
"Over the next two weeks, engineers will review the data from these tests and consider what steps to take next," Hunter said. "Although both wheels have shown motion, the friction levels will be critical in future considerations. The details of the wheel friction are under analysis."
There's no chance of NASA mounting a human fix-it mission to the Kepler telescope. It orbits the sun some 40 million miles from Earth – but the good news about the reaction wheel suggests Kepler's mission might be extended.
Kepler has been considered a major NASA success—it has confirmed 134 extra-solar planets since its launch in 2009. It has also detected another 3,200 possible planets that still require confirmation, though scientists estimate based on its previous successes that about 90 percent of those potentials will be confirmed.
Even if the telescope isn't able to look for planets again, NASA officials still have about two years' worth of unexamined data produced by Kepler to sift through. Many more planets could be hidden within.