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Kepler Makes First Exoplanet Discovery After Mission Reboot

Posted by samzenpus on from the look-what-we-found dept.

astroengine writes NASA's Kepler space telescope has detected its first new extrasolar planet after mission engineers were able to save the mission from a premature death after two of the exoplanet hunter's four stabilizing reaction wheels failed last year. Called "K2," the extended mission arose from an "innovative idea" that appears to have given the prolific telescope a new lease on life. "Last summer, the possibility of a scientifically productive mission for Kepler after its reaction wheel failure in its extended mission was not part of the conversation," said Paul Hertz, NASA's astrophysics division director at the agency's headquarters in Washington D.C. "Today, thanks to an innovative idea and lots of hard work by the NASA and Ball Aerospace team, Kepler may well deliver the first candidates for follow-up study by the James Webb Space Telescope to characterize the atmospheres of distant worlds and search for signatures of life."

28 comments

  1. Why do these reaction wheels keep failing? by flowerp · · Score: 2

    Isn't there any technology to keep reaction wheel discs floating in a vacuum chamber instead of using mechanical bearings?
    How about magnetic suspension and frictionless motor drives? This has to be possible with today's technology.

    Christian

    --
    --- Eat my sig.
    1. Re:Why do these reaction wheels keep failing? by Anonymous Coward · · Score: 0

      You idiot, Christian isn't asking for a reaction wheel to last a "bajillion" years... but a 50% failure rate, in 4 years is pathetic! The reality is that we DO spend a massive budget on spacecraft worldwide and many of them use reaction wheels. We should be able to build a more reliable one.

    2. Re:Why do these reaction wheels keep failing? by Anonymous Coward · · Score: 0

      I think you are over-reacting a little.

    3. Re:Why do these reaction wheels keep failing? by PPalmgren · · Score: 1

      Magnetic suspension? That sounds quite costly on a power budget, and a lot of these probes have really tight power budgets. Plus, you'd have to build in the ability for it to not get ripped apart during launch, which means overengineering the magnetic suspension just to get it off the ground even though that excess capability will never be used in space. I'd think mechanical reaction wheels would be a cinch to lock in comparison.

      I'm probably wrong, but that was my initial gut thoughts on the subject.

    4. Re:Why do these reaction wheels keep failing? by flowerp · · Score: 1

      Well you could secure the wheel using some rectractable bolts during launch. Only when in orbit you retract these bolts and then you turn on your electromagnets.

      I found quite a lot of research papers on magnetic suspension of reaction wheels. I really wonder why this isn't mainstream technology yet.

      Christian

      --
      --- Eat my sig.
    5. Re:Why do these reaction wheels keep failing? by Anonymous Coward · · Score: 0

      Seems like it might be a failure of his reaction wheel stabilzation module.

      That happens. But a little gentle peer pressure can keep such a person productive.

    6. Re:Why do these reaction wheels keep failing? by Will.Woodhull · · Score: 1

      There is such technology. On Earth. In space there are limitations of weight and energy consumption to contend with.

      --
      Will
    7. Re:Why do these reaction wheels keep failing? by MouseR · · Score: 1

      A bajillion dollars wont work.

      You need rubber.

    8. Re:Why do these reaction wheels keep failing? by werepants · · Score: 1

      Kepler was designed with a 3.5 yr mission life. It is now going on its 6th year in space. So it met what it needed to do and is STILL producing science. If they had blown time/money/mass on a fancier reaction wheel system, they might've had to sacrifice science payload, or power margin, or had the project go over schedule and over budget and get cancelled altogether. Not to mention that some other, more critical part could've failed because they would have had to sacrifice margin elsewhere.

      Perfect is the enemy of good. I swear, if NASA shoots for all the capabilities and tries to make sure nothing can go wrong, ever, we get things like the JWST which is years behind schedule and severely over budget. If they do a sensible, focused mission that makes sure to be Good Enough while staying on time and affordable, people complain that it doesn't last forever (even though it has already almost doubled its design life).

      Do you really think that in the 30 seconds it took you to read that summary and write your comment, you managed to come up with something that entire teams of NASA engineers who do this for a living didn't think of? Or maybe your job is easy enough that random slashdotters who scarcely understand it can offer you meaningful advice on how to do it.

    9. Re:Why do these reaction wheels keep failing? by werepants · · Score: 2

      It wasn't 4 years, it is closer to 6. Launched in March '09. Secondly, there was a 3.5 year mission life, which Kepler satisfied. Now, even after sustaining some part failures, it continues to do valuable science. So, in fact, it looks like we've got a system that met all objectives and is working far past its design life - if that is pathetic, what would qualify as a success in your eyes?

    10. Re:Why do these reaction wheels keep failing? by werepants · · Score: 1

      Here's the thing. Imagine that you are a mechanical engineer, told to build a reaction wheel system that will have something like a 99% chance of lasting 3.5 years, and do it as cheaply, quickly, and lightly as possible. Are you going to pick an unproven, brand new bearing design that introduces lots of extra complexity, would probably involve a lot of new ($$$) and custom design work, and which require all the testing and validation that is involved to qualify a new technology for spaceflight? For starters - prove that any EM fields wouldn't impact the rest of the system, show it can tolerate any failure without having a detrimental impact on the rest of the system, characterize its failure signatures for diagnostics, figure out precisely how far it can be driven, for how long. While you are at it make sure that it can do all of this in any temperature and pressure. And cycle it through several lifetimes of use to make sure you understand how it will fatigue.

      This is essentially the scenario the engineer on this project faced. 3.5 years isn't an atrocious design life, there are certainly tried and proven reaction wheel designs that have met that requirement in other spacecraft. Kepler wasn't a technology demonstrator - it was a science mission with a specified design life (that it satisfied) and using a simple reaction wheel was the right choice here.

      If you think it should have been more reliable, blame the principal investigator or NASA administration or Congress, who all played their own parts in determining the design life (and hence budget) for this program. If you think it should use something newfangled for its own sake, well, it wasn't that kind of mission to begin with. If you think new, fancy technologies should be used to improve reliability, well, you don't understand reliability very well - you don't build a reliable system by using unproven designs, you use things that are tested and understood and try to minimize the big, risky unknowns.

      For the record, the space industry IS working on replacements for reaction wheels, but it is doing it first on inexpensive satellites and technology demonstrators, so that it can later become commonplace. Reaction wheels themselves are probably going to become obsolete for many LEO and MEO applications before magnetic bearings even come into wide use, because electromagnetic torqueing tech can react against the Earth's magnetic field for orientation, and uses no moving parts, and never has to bleed built-up velocity off the reaction wheels (which costs propellant).

    11. Re:Why do these reaction wheels keep failing? by K.+S.+Kyosuke · · Score: 1

      For these missions, though, it's generally desirable for the vehicle to last as much as you can make it. Surely the average scientific return per day from Opportunity is much, much cheaper now that it's been operating for ten years than it would have been had it only worked for the originally planned ninety days.

      --
      Ezekiel 23:20
    12. Re:Why do these reaction wheels keep failing? by K.+S.+Kyosuke · · Score: 1

      That doesn't mean that people aren't trying, though.

      --
      Ezekiel 23:20
    13. Re:Why do these reaction wheels keep failing? by werepants · · Score: 1

      Of course, but you can't design for infinite lifespan. You design for the mission, add margin as required, and if it lasts longer, great. Almost always, it does, but this is a probability thing - there's every chance that you could get a 1 in a million, mission ending event on day one - there's no such thing as zero chance of failure. If you design for longer than required, you are spending more money/mass/time than you have to.

      The real question is up to the principal investigator and his/her science team in a mission like this. I would expect that the scientific return over time of most missions trends towards zero - not to say that it is useless to keep a long-lived system limping along, but just to say that many of the biggest questions are answered in the first days, and there's an inherent balance with increasing longevity - what's better, a 10 yr design with meager instrumentation, or a 1 yr mission with more sensing/data collection? These are the trades you have to make, since budgets, schedules, and basic physical laws mean you can't always have everything you want, when you want it, for the price you are willing to pay.

      For the record, I work in the industry and these questions directly impact the work that I do - designing towards a 2 year lifespan vs a 10 year lifespan can easily change the cost of a mission by orders of magnitude, and it is ignorant to act as though a failure AFTER the design life is a fault of engineering. That would be like criticizing a car rated for 20mpg for only getting 30mpg - it isn't a faulty design, it is faulty expectations.

      I also highly recommend reading something like Roving Mars, by Steven Squyres - he was the PI on Spirit and Opportunity, and you get a look at the tough choices and gambles they had to make as part of that mission. It turns out that they made some pretty good choices, and the dice rolled their way in a lot of cases. It is easy to figure out where you would have put more resources once the mission has flown and you know what failed - it's another matter entirely to figure out where to invest your time and risk management up front. Hindsight and all that.

    14. Re:Why do these reaction wheels keep failing? by K.+S.+Kyosuke · · Score: 1

      All you're saying is true, but I think we've had enough problems with space-based moving parts (the assorted reaction wheels, Voyager 1 and 2 scan platforms etc.) compared to non-moving parts that finding a reasonable solution to this problem seems like something that everyone could benefit from. If a number of long-distance scientific missions have all the components working with the exception of moving parts, it would appear that moving parts with long lifetimes are the next major problem to solve. Voyagers had problems early on. That made the scientific output from Voyager 2 diminished even before it got to Uranus and Neptune. It's not just about extended missions in some cases.

      --
      Ezekiel 23:20
    15. Re:Why do these reaction wheels keep failing? by whodunit · · Score: 1

      Dude. http://classic.slashdot.org/st... You're welcome.

  2. Why do these reaction wheels keep failing? by Anonymous Coward · · Score: 0

    Not with a rather limited budget.

    Sure, give them a bajillion dollars and they'll build the Death Star or the USS Enterprise.

    But that's not reality.

  3. Surely not by Anonymous Coward · · Score: 0

    Did they have to reinvent the wheel?

    1. Re:Surely not by JustLikeToSay · · Score: 1

      Perhaps they moved from round to square (kilometre array).

      --
      I know the truth and I know what you're thinking
  4. We suck as a people by argStyopa · · Score: 2

    Seriously, we do.

    The fact that we're finding other PLANETS is now so humdrum that this gets 7 comments, this smells very much like the latter Apollo missions "Oh, we've got guys on the moon again? Zzzz."

    If I simply posted something controversial*, like an entire article about how "global warming is bullshit", that would get 300 comments, easily.

    *of course, I can't use /. as my personal blog. I'm not Bennett Haselton.

    --
    -Styopa
    1. Re:We suck as a people by kelemvor4 · · Score: 1

      Seriously, we do.

      The fact that we're finding other PLANETS is now so humdrum that this gets 7 comments, this smells very much like the latter Apollo missions "Oh, we've got guys on the moon again? Zzzz."

      If I simply posted something controversial*, like an entire article about how "global warming is bullshit", that would get 300 comments, easily.

      *of course, I can't use /. as my personal blog. I'm not Bennett Haselton.

      More than 1800 exoplanets have been discovered. At some point, finding one more ceases to be big news.

    2. Re:We suck as a people by Coren22 · · Score: 1

      I was more interested in how they were able to run with only two wheels, that is more interesting at this point.

      It turns out (pun intended) that they use the solar radiation pressure as the third wheel.

      --
      APK likes to ask for responses to the same things over and over. Maybe he just likes the responses?
    3. Re:We suck as a people by wonkey_monkey · · Score: 1

      If I simply posted something controversial*, like an entire article about how "global warming is bullshit", that would get 300 comments, easily.

      That's practically a tautology. Of course you'll get comments if you post something controversial, since those tend to be matters of opinion and everyone's got a different one.

      If you post about something that's a plain, simple fact (such as this discovery of yet another exoplanet) there really isn't a lot of room for discussion. 300 "Yes, this is a thing that happened" comments don't contain a lot of information.

      The fact that discovering exoplanets has become routine is, in and of itself, awesome, but that happened some time ago.

      --
      systemd is Roko's Basilisk.
    4. Re:We suck as a people by green+is+the+enemy · · Score: 1

      But this is not just another exoplanet. It's the Kepler spacecraft being back in business. I think that's news-worthy. By looking at many different patches of sky they will detect many more exoplanets. The only downside is that they won't be able to observe each patch very long, so only short period planets would be discovered. That's still lots of valuable scientific data. The way they precision-point this telescope now is also interesting.

    5. Re:We suck as a people by WrongMonkey · · Score: 1

      So people care more about the planet we're living on and the policies used to govern it more than they care about some dead rocks in space. Is that really so surprising?

    6. Re:We suck as a people by anonymousJUGGERNAUT · · Score: 1

      Hear, hear. This is exciting stuff in my book. I'm very happy Kepler is gathering data again, though still slightly frustrated that it didn't last longer with its full capabilities.

  5. And the innovative idea is... by wonkey_monkey · · Score: 1

    Nice bit of click-baiting, failing to mention what the innovative idea actually was:

    To maintain stability during its new campaign, mission engineers turned to the sun for help, using the continuous pressure of photons from sunlight to act as a counterbalance.

    --
    systemd is Roko's Basilisk.
  6. Pluto by Anonymous Coward · · Score: 0

    If these probes telescopes are so good, then point them at Pluto, and Neptune. Analyze the crap out of them to come up with a model, then when the Horizon probe gets there, we can see for ourselves how accurate the telescopes actually are.