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NASA Abandons Kepler Repairs, Looks To the Future

Posted by Soulskill on from the time-to-crash-it-into-planet-genesis dept.

cylonlover writes "If NASA has anything to say about it, Kepler is down, but not out. At a press teleconference on Thursday it announced that it has abandoned efforts to repair the damaged unmanned probe, which was designed to search for extrasolar planets and is no longer steady enough to continue its hunt. But the space agency is looking into alternative missions for the spacecraft based on its remaining capabilities. 'On Aug. 8, engineers conducted a system-level performance test to evaluate Kepler's current capabilities. They determined wheel 2, which failed last year, can no longer provide the precision pointing necessary for science data collection. The spacecraft was returned to its point rest state, which is a stable configuration where Kepler uses thrusters to control its pointing with minimal fuel use.'"

18 of 73 comments (clear)

  1. A partial success by Anonymous Coward · · Score: 3, Interesting

    It was supposed to have a 3.5 year mission. It appears that it might have come pretty close to that, but it didn't get nearly the data it was supposed to. This is pretty disappointing and they should probably hold a formal design review to determine what went wrong in the design and construction and determine if a replacement should be built to finally accomplish the mission that was planned.

    1. Re:A partial success by rraylion · · Score: 5, Interesting

      as with most satellite missions gone wrong -- its was the gyroscope.... remember it was replaced on Hubble a few times... its seems to be the weakest link in a lot of missions as it has to be a moving part to induce counter rotation in the satellite. it's only feasible to put so many on board ... so maybe a redesign of this one part will save future missions ... but maybe its time to think outside the box now that we know ion drives work a kg of propellant and three exhuast ports would fix this issue with new tech

      Other than that it was an awesome mission.

    2. Re:A partial success by Kjella · · Score: 5, Informative

      as with most satellite missions gone wrong -- its was the gyroscope

      Actually the gyroscopes lasted the original 3.5 year mission, but due to more noise than anticipated they collected less data than planned - which was why the mission was extended to 7.5 years. Now they won't be able to finish that, but that was really the backup plan failing. Oh well, not everything can be a Mars Rover exceeding all design specs by leaps and bounds.

      --
      Live today, because you never know what tomorrow brings
    3. Re:A partial success by Electricity+Likes+Me · · Score: 2

      Didn't NASA have reaction wheels go on another probe as well? The one we're sending to explore Ceres I think had reaction wheel issues as well and had to be reconfigured to run its mission on thrusters as well.

      It certainly seems like this is probably going to be a big engineering challenge into the future since super-steady stargazing probes are hardly going out of fashion. Though I suppose the better issue is "can we make some of this stuff replaceable/repairable cost effectively?"

    4. Re:A partial success by Sockatume · · Score: 4, Informative

      To nitpick, they collected as much data as planned, but it was noisier than expected. Therefore they needed more data to bring the signal above the noise. Interestingly the source of the noise isn't Kepler, but sunspots on the stars causing fluctuations in the brightness. They'd counted on a 3.5 year mission being long enough to collect a strong enough signal by assuming sunspot noise was the same as from the Sun, but it turned out it was actually stronger.

      --
      No kidding!!! What do you say at this point?
    5. Re:A partial success by Yoda222 · · Score: 4, Informative

      You can control attitude using (ion) thruster, but reaction wheels have some advantages. One of the biggest advantage of RWs is that it's (close to) a linear actuator (outside of the zero crossing zone), where thruster are bang bang actuators. In fact they are bad bang bang actuator, because you have some transient at start and end of the pulse.

    6. Re:A partial success by cusco · · Score: 2

      What went wrong with the design? Congress and The Office Of Management and Budget (aka TOMB), probably. That seems to be the issue with pretty much every problem we ever encounter in the space program. When lawyers and accountants get to decide that they know how to design spacecraft better than rocket scientists trouble is pretty much guaranteed. What do you want to bet that another layer of redundancy had to be eliminated because of budgetary concerns?

      --
      "Think about how stupid the average person is. Now, realise that half of them are dumber than that." - George Carlin
    7. Re:A partial success by Strider- · · Score: 5, Informative

      Didn't NASA have reaction wheels go on another probe as well? The one we're sending to explore Ceres I think had reaction wheel issues as well and had to be reconfigured to run its mission on thrusters as well.

      Reaction wheels a very well known concepts in spaceflight. The ISS uses them to point itself (The Control Moment Gyros) and pretty much any and all geosynchronous satellites also use reaction wheels to keep themselves pointed at earth. This is actually how they ended up recovering Galaxy 15. After several months of drifting while "zombie", the reaction wheels finally saturated (spinning as fast as they could go) causing the satellite to lose earth lock, and go into a safe mode.

      Anyhow, the upside and downside is that they are relatively simple devices, and allow for very precise and stable pointing without spending a lot of fuel (you don't want your exhaust condensing on your optics in a telescope now do you?), but at the same time they're mechanical devices, and thus are more fragile than something that's purely solid state.

      --
      ...si hoc legere nimium eruditionis habes...
    8. Re:A partial success by Anonymous Coward · · Score: 4, Funny

      Given how common this mode of failure is, throwing a lot of money into the study of better reaction wheel designs would probably pay off for a slew of future missions.

      [I can't believe I just said that]

    9. Re:A partial success by Firethorn · · Score: 2

      At least part of the reason for the extra expenses is that Congress will often starve the projects of money over the years, forcing NASA to work slower - and as it costs money to simply 'keep the lights on', it results in overruns. Then there's the whole 'part of it has to be built in MY district', etc...

      A program that might cost $5M to build and launch a satellite over 3 years might coast $10M to do the same over 10 years.

      --
      I don't read AC A human right
  2. Heard about this on NPR by ACK!! · · Score: 4, Interesting

    It seems that NASA is challenging the scientific community to come up with new projects or experiments that could still work despite the Kepler's limitations now. So it is time for all the scientists with their eyes toward the sky to start dusting off the keyboards and to come up with some cool new proposals. So even though it was not a screaming success the project could still turn out to be important to the scientific community going forward. If we have some scientists who can come up with neat ideas on how to use the capabilities this device still has.

    --
    ACK /ak/ interj. 2. [from the comic strip "Bloom County"] An exclamation of surprised disgust, esp. i
    1. Re:Heard about this on NPR by steelfood · · Score: 2

      Data collection may have ended, but the analysis has certainly not. We can't gauge the success of the mission to any degree of accuracy until all the data is analyzed. It's been enormously successful thus far in finding exoplanets, but the unanalyzed data may yet yield greater discoveries.

      And even data collection may still be possible. There is mention of using software to do the correction, rather than relying on hardware. I don't know how feasible this would be when most stars are a few pixels wide at the most, but it'd nonetheless be interesting to see what comes out of this idea.

      --
      "If a nation expects to be ignorant and free in a state of civilization, it expects what never was and never will be."
  3. Re:2 gyroscopes left... by rubycodez · · Score: 2

    useless for finding the very slight variations in brightness on a pixel and nearest neighbors when compared to same over month or more than a year, on which kepler's detection methods depend.

  4. a fix by rubycodez · · Score: 4, Interesting

    deploy another gyroscope and rpg in a package that can be attached to Kepler, a practice run for comet sampling missions

  5. Proposals due at the end of the month by Anonymous Coward · · Score: 4, Interesting

    The problem is Kepler doesn't really have the resolution for things we're interested in and may not actually be able to be pointed in certain directions due to solar panel and communications relay positioning. Best we could come up with at our brainstorming meeting this morning was parallax with our upcoming mission to Pluto and to resolve a bet on whether or not ISON will explode when it passes close to the sun later this year.

  6. Re:2 gyroscopes left... by fuzzyfuzzyfungus · · Score: 2

    useless for finding the very slight variations in brightness on a pixel and nearest neighbors when compared to same over month or more than a year, on which kepler's detection methods depend.

    I imagine that that is why they are asking for proposals from scientists who have ideas for what you can do with a fairly nice telescope, already in orbit, just need to pay upkeep on the ground station, that don't require the original precision of which Kepler was formerly capable.

    As long as the optics are good, and the control is not totally shot, it's still a pretty decent telescope, and people are practically shivving each other for time on good telescopes.

  7. Ithaco Space Systems built the reactions wheels? by Squidlips · · Score: 2

    It seems that Ithaco Space Systems built the control wheels according to this article in Nature. They supplied the failed control wheels for Kepler and Dawn and other missions....and they were not cheap. Great job there... http://www.nature.com/news/the-wheels-come-off-kepler-1.13032

  8. Re:What is it with momentum wheels, anyway? by Squidlips · · Score: 2

    Talk to Ithaco Space Systems. They built the control wheels according to this article in Nature. They supplied the failed control wheels for Kepler and Dawn and other missions....and they were not cheap. http://www.nature.com/news/the-wheels-come-off-kepler-1.13032