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NASA Space

Equipment Failure May Cut Kepler Mission Short 76

Posted by Soulskill
from the unless-they-can-macgyver-up-a-solution dept.
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.'"
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Equipment Failure May Cut Kepler Mission Short

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  • Futurama (Score:5, Funny)

    by Okian Warrior (537106) on Wednesday May 15, 2013 @04:18PM (#43735323) Homepage Journal

    Obvious Futurama response:

    http://www.youtube.com/watch?v=1Isjgc0oX0s [youtube.com]

  • Sad news for such a promising mission.
  • by Anonymous Coward

    Surely the odds are astronomical?

    • That's what they said about the chances of anything coming from Mars (or was that landing on Mars?). But still...
  • Poor guy (Score:5, Funny)

    by pseudofrog (570061) on Wednesday May 15, 2013 @04:31PM (#43735417)
    That little probe has been put through a lot. I guess it would be okay to let it come home a little early. Maybe it can help prepare a party for its rover friends when they make it back! :)
  • Replacements (Score:5, Informative)

    by Anonymous Coward on Wednesday May 15, 2013 @04:41PM (#43735487)

    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.

  • by mbone (558574) on Wednesday May 15, 2013 @04:43PM (#43735519)

    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 [nasa.gov] 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.

    • by queazocotal (915608) on Wednesday May 15, 2013 @05:01PM (#43735697)

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

      One of the things that was discovered early on was that the sun was not a sun-like star.
      It is unusually quiet - with little variation in brightness. Most of the population of stars observed by Kepler turn out to be lots noisier.
      This unfortunately made the primary mission - which was to detect earth like planets in earth like orbits - not achievable in the original timescale.

      With an extended mission, you can dig through more data, and get enough signal from multiple planet crossings to bring it up out of the noise, getting you back to where you would have been had the original mission assumptions been correct.
      Unfortunately, the wheel failure seems to have constrained this.
      At best the degraded pointing mode they may end up in will have much more noise in the signal, making it much less useful for many purposes.
      (It will likely still be able to detect very large far out planets)

      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.

      • Re: (Score:3, Informative)

        by 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.

      • by edxwelch (600979)

        Be that as it may, the hardware was only designed to last till the expected mission end - which it did - so you can't really complain about it not lasting till 2016

      • Is there some other way to use this instrument in it's hobbled state? Lunar mapping? Asteroid hunting? Etc...?? Would be nice to salvage the hardware, even if the primary mission is toasted.

    • by mrtommyb (1534795)
      Kepler has very likely found al the hot Jupiters in the field of view. Almost all hot Jupiters were found in the first few weeks of the mission. The mission may be able to continue to search for Jupiter-sized planets on Earth-like orbital periods. However, it's not clear whether this is either possible or worth the expense. The cost will be high given an entirely new mode of operations will need to be designed in a relatively short space of time.
  • I would have thought that adding a few extra comparatively simple mechanical components, commonly understood to be error-prone (remember Voyager 2...) into a billion dollar mission would be a no-brainer.
  • The reptoids will stop at nothing to prevent humans from finding their homeworld!

    But seriously, bummer. Many years ago (1997!) I went to a NASA Ames / Moffet Field open house. Various working groups had set up displays showing the mission concepts they were working on. One of these was Kepler.

  • Is it me, or do reaction wheels seem to be the most failure prone part of space telescopes?

  • Something tells me if they want to, they can fix it. Eventually.
    • by Sperbels (1008585)
      Well, considering that Hubble is in Earth orbit and Kepler is not, that would be pretty difficult.
      • ...Oh ye of little faith
      • by iggymanz (596061)

        kepler is in an earth trailing orbit, 6 million miles away, we can get to it

        • by Sperbels (1008585)
          Using what? We have no manned space vehicles. Russia and China certainly have no vehicles designed for such a journey. And at 6 millions miles, that's 25 times the distance between earth and the moon. But I think that 6 million is wrong, I've seen other sources quoting it at 40 million. We could *manufacture* a ship to get there....but that would take some time...and be kind of pointless since the telescope could simply be replaced for a fraction of the cost.
          • easy. if it's in earth trailing orbit, just launch something out of earth orbit, and the stop it. Kepler will eventually come along, and whatever we've sent up came just fix it. Shouldn't put us off just because it'll be going at 107,200 km/h...

  • Obviously the Galactic Ghoul [wikipedia.org] operating on an interstellar scale. I'd be taking a good hard look at the systems next up on Kepler's observing schedule...
  • Did you try switching it off, then switching it back on?
    • I don't expect anyone to read TFAs, but you could at least read TFS ;)

      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.

  • Just send the space shuttle up to fix it.

    Oh wait...

    • by Mr2cents (323101)

      The shuttle was nowhere near capable of flying to Kepler. It's at 40 million miles, while the space shuttle could only fly up a couple hundred miles. Besides, considering the cost of the mission, it would not warrant a complicated repair mission. For that money you could probably send up 10 new telescopes.

  • If only we had a vehicle we could send up with some astronauts to fix it. Couldn't be any harder than fixing Hubble could it? Oh, right.....
  • by ridgecritter (934252) on Wednesday May 15, 2013 @11:46PM (#43738195)

    These seem to be a relatively common source of woe for spacecraft that use them. I understand it's moving parts and all that, but surely in 0-G there can't be *that* much wear on bearings. Anyway, there seems to be plenty of work on magnetic bearings for momentum wheels, which would eliminate mechanical wear. Or is it not the bearings that fail? Can any /. readers shed some light on why these things seem to pack it in so frequently?

    • You'd also think they's have these attached to the spafe station for many years, so they could study wear and tear on it.

    • The problem might not be wear and tear, it might be ice forming somewhere in the wheel system. Normal ice can be evaporated away by heating up the instrument, but when I say 'ice', I mean deposits of some material -- vaporized rubber, outgassing paint, or even neutron spalling. All of those could add friction to the system, can't be easily removed, and may have nothing to do with the bearings.

  • TODO list (Score:4, Insightful)

    by Mr2cents (323101) on Thursday May 16, 2013 @07:24AM (#43739569)

    - Make better reaction wheels
    - Make better valves

    Those two things always come back when missions end, or when a rocket launch has to be delayed.

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