Equipment Failure May Cut Kepler Mission Short

HyperbolicParabaloid writes "According to the New York Times, an equipment failure on the Kepler spacecraft may mean the end of its planet-hunting mission. One of the reaction wheels that maintains the craft's orientation — critical to long-exposure imaging — has failed. 'In January engineers noticed that one of the reaction wheels that keep the spacecraft pointed was experiencing too much friction. They shut the spacecraft down for a couple of weeks to give it a rest, in the hopes that the wheel’s lubricant would spread out and solve the problem. But when they turned it back on, the friction was still there. Until now, the problem had not interfered with observations, which are scheduled to go on until at least 2016. Kepler was launched with four reaction wheels, but one failed last year after showing signs of erratic friction. Three wheels are required to keep Kepler properly and precisely aimed. Loss of the wheel has robbed it of the ability to detect Earth-size planets, although project managers hope to remedy the situation. The odds, astronomers said, are less than 50-50.'"

Comments

Replacements

[Anonymous Coward]

Worry not! NASA's TESS and ESA's Gaia missions will be there to pick up the slack. Gaia launches this year and TESS in 2017.

Re:Replacements

[mbone]

There is also ESA's CHEOPS, a planet finder, also intended for launch in 2017.

Primary mission already over

[mbone]

It's the extended mission (to 2016) that may be cut short. The primary mission is already over, in 2012.

They still have 2 reaction wheels, and also thrusters, and a fair amount of fuel. In the press release there was a discussion of options, which "are likely to include steps to attempt to recover wheel functionality and to investigate the utility of a hybrid mode, using both wheels and thrusters."

My guess is that, if they cannot recover pointed mode, they will put the spacecraft in a slow roll, which (if it is slow enough) would be good enough to detect hot Jupiters, but not Earth-like planets.

Re:Primary mission already over

[Anonymous Coward]

Another unfortunate fact is that the data from the cameras is very 'cooked' onboard - most of the data is thrown away automatically. This would make doing clever things to fix the problem in software on the returned data hard. How flexible the on-craft pipeline is is an interesting question.

The data from the CCDs is not "cooked" very much at all. See http://arxiv.org/abs/1001.0258 There is no on-board pipeline. It's just that only 5% of the pixels are saved for downloading. With the spacecraft not at fine point this means the light from each star gets spread out to more pixles. This means more pixels per target star and therefore fewer targets.

Re:so much for...

[X0563511]

Maybe you missed the part where it mentioned the fact that they -had- redundancy, and that one had also failed?

It has plenty

[dutchwhizzman]

They added an extra wheel and whatnot to let it make it's mission, which officially ended in 2012. It is already in extended time and all data we get from it now is essentially a bonus.

Re:Karma

[wooferhound]

Reaction Wheels on spacecraft have always had problems and fail regularly. They are only on spaceships that are flying in space as they are used to orient the ship without using fuel. Rovers don't need them.