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Mars NASA Space Science

NASA Mars Rover Spirit May Move Forward By Spinning Its Wheels 175

Posted by timothy
from the we'll-call-this-the-mars-paradox dept.
coondoggie writes "As NASA celebrates its Mars rover Spirit's sixth anniversary exploring the red planet, it is hunting for a way to keep the machine, which is mired in a sand trap, alive to see a seventh year. On its Web site, the space agency this week noted there may indeed be such an option. That option would be spinning the wheels on the north side of Spirit, letting it dig in deeper in the Martian sand but at the same time improving the tilt of the rover's solar panels toward the Sun."
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NASA Mars Rover Spirit May Move Forward By Spinning Its Wheels

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  • by Vyse of Arcadia (1220278) on Friday January 01, 2010 @04:43PM (#30616048)
    That ranks up there with "People kept alive by breathing."
    • by Anonymous Coward on Friday January 01, 2010 @04:53PM (#30616112)

      "Spinning its wheels" is technically what wheeled vehicles do while in motion, but idiomatically, it refers to wheelspin on sand/snow/etc. that doesn't result in forward/backward motion. It's commonly used as a metaphor for futile action, and so when the literal case turns out to be beneficial, the result is a mildly amusing headline. To use your example, it's more like "people kept alive by breathing water", in that it's the opposite of what you'd expect.

  • by Anonymous Coward on Friday January 01, 2010 @04:45PM (#30616062)

    Floor it!

  • Somehow I have a bad feeling that while allowing the rover to remain operational for a bit longer, it will also ironically become stuck in the hole it dug.
    • Re: (Score:3, Informative)

      by mea37 (1201159)

      Yes, that is likely what would happen. What they're saying is, they may not be able to get the rover out, and if not this will provide the longest lifetime for observations from the now-stationary rover.

      • And one should add (Score:5, Insightful)

        by Sycraft-fu (314770) on Friday January 01, 2010 @05:14PM (#30616220)

        The rover was designed for a 90 day mission. If it made it to Mars operational, and was capable of operating for 90 (martian) days, the mission was a success. Here we are, years later and it is still working. It isn't as though this is a panic "Oh no we have to save the mission!" kind of thing. Rather, this is another step to see how long they can extend a tremendously successful mission. Even if the rover dies tomorrow, it will have far surpassed any expectations set for it.

        Also of note is that Opportunity, the other of the two rovers launched, is currently trucking along towards a crater they want to look at.

        • Re: (Score:1, Insightful)

          by Anonymous Coward

          This is a blantant example of reverse sandbagging, they give really low expectations so they can claim big success.
          On the other hand, this mission has gone on for six years so they can really pat themselves in the back since like 3 years ago.

        • by selven (1556643) on Friday January 01, 2010 @06:10PM (#30616548)

          Was it really designed for 90 days? It could be that the only way they could sell it to Congress was if they told them that they only had to pay for technicians for 3 months.

          • by CarlDenny (415322) on Friday January 01, 2010 @06:33PM (#30616714)

            90 days may have been something of a lowball, but the expectation was that dust would accumulate on the rover's solar cells, gradually reducing their power output. Turns out, the dust wasn't as sticky as they thought, and the wind will blow it off on clearer days. That's a genuine discovery, and the main longevity boost. NASA can and have happily paid for a lot more ground crew and radio time for the little ladies.

          • by Kjella (173770) on Friday January 01, 2010 @09:35PM (#30618308) Homepage

            Was it really designed for 90 days? It could be that the only way they could sell it to Congress was if they told them that they only had to pay for technicians for 3 months.

            Well, yes and no. The models suggested that the solar panels would be clogged up with dust so it'd be like a car with an empty gas tank, after 90 sols it'd be still in great condition but out of juice so that was the mission. In practice dust devils clear most of the dust, but noone knew that before they arrived. Perhaps some speculated and hoped, but certainly not knew or assumed. Nothing about the rover was intentionally limited to three months, though if they knew they'd be out there for many years I'm sure some design choices would have been different. But that's why we can send a second generation if and when these rovers finally kick the bucket.

          • by Belial6 (794905)
            Well, the price the quoted was acceptable for a 90 day mission. If they were able to build a device that lasts far longer for the price of one that would only last 90 days, then hurry! Success!
        • by Osmosis_Garett (712648) on Friday January 01, 2010 @06:28PM (#30616680)
          Actually, Opportunity is examining the damaged heat shield from re-entry, which it just arrived at the other day [blogspot.com].
        • Here we are, years later and it is still working. It isn't as though this is a panic "Oh no we have to save the mission!" kind of thing.

          The very fact that Spirit has worked so tremendously well up to now means that it is still an extremely valuable device. It's worth spending every effort to save the rover now, precisely because it has shown itself able to surpass its original goals by so much. In other words, age has increased rather than decreased its worth.

    • It's already stuck. They have been trying to free it for the better part of a year. If it runs out of power, it's not going to move ever again. So they are desperate to get it tilted to improve the power situation.

                Brett

    • by NotBorg (829820)

      So they go from stuck to stuck. What's the difference?

      • by Geoffrey.landis (926948) on Friday January 01, 2010 @05:11PM (#30616212) Homepage
        The difference is that winter is coming, and the sun gets low on the horizon. We can, if we chose, dig in on one side so that we tilt toward the sun, which means that we will get more solar energy, and so the solar powered rover will survive the winter.

        (We've tilted the rover into the sun every winter so far-- if we don't, this will be the first winter we've tried to survive without tilting into the sun)

        • by sdpuppy (898535)

          That option would be spinning the wheels on the north side of Spirit, letting it dig in deeper in the Martian sand but at the same time improving the tilt of the rover's solar panels toward the Sun."

          The difference is that winter is coming, and the sun gets low on the horizon.

          Good idea - I saw someone do that with their car the other day and - dang - you should have seen the guy zoom outta there.

          :-)

      • The difference is between "stuck" and "stuck and dead".
    • by Kjella (173770)

      Well it's been stuck now for a long time, if they can't get it loose then it'll die anyway. Right now this is more a marathon event to see how long they can stay alive than anything else, they must have done every secondary and tertiery science mission ever planned for it and is just making it up as they go along now.

      • by Tablizer (95088)

        There are some unexplored rock formations around it's area, dubbed "Home Plate", that they wanted to explore more if it was mobile. But even if they could free it from the dust trap, it has only 4 good wheels left, meaning its mobility is limited to very flat and safe areas if it ever escapes.

  • Heh (Score:4, Interesting)

    by ShooterNeo (555040) on Friday January 01, 2010 @05:00PM (#30616158)

    You know what the solution to this problem is? Send more rovers. Lots more. If we had a spare rover near Spirit, we could probably have it roll over and give Spirit a tow...

    • Re: (Score:3, Interesting)

      by Baron_Yam (643147)

      You know what? I'm not a NASA planetary exploration scientist, but that sounds like an interesting idea.

      Send rovers in pairs, each with half the instrumentation load, but tethered together by a cable. One gets stuck, the other pulls it out. Give the cable a release so if one rover dies, the other can continue with the remaining instruments.

      • Re:Heh (Score:5, Funny)

        by CarlDenny (415322) on Friday January 01, 2010 @05:16PM (#30616234)

        Except then you're putting all your eggs in one basket if there's a landslide that drags them both down, a sandstorm that prevents solar charging, or a problem on landing.

        Maybe if we sent up two identical rovers, but dropped them off independently at different points on the planet?

        • by Abstrackt (609015)

          Maybe if we sent up two identical rovers, but dropped them off independently at different points on the planet?

          NASA's going to need a pretty long cable for that.

      • Yes, but getting them to mars intact is still a big problem.
        • Re: (Score:1, Insightful)

          by Anonymous Coward

          Yes, but getting them to mars intact is still a big problem.

          Although we seem to be doing rather well at it.

          • Not really. The Mars Polar lander was lost, Deep Space 2 was lost, and Europe lost Beagle 2. Russia lost the landers of Mars 2, 3 and 6. Really, Spirit, Opportunity and Phoenix are the only rovers to make it.
      • by Kjella (173770)

        Send rovers in pairs, each with half the instrumentation load, but tethered together by a cable. One gets stuck, the other pulls it out. Give the cable a release so if one rover dies, the other can continue with the remaining instruments.

        One of the key issues is having power enough to heat them in the winter. For that reason alone it's probably better to build a bigger, more durable platform instead. It's not like it didn't have redundancy, each wheel has a separate drive and it's not like a fully operational rover would get stuck like this. They're just running out of redundancy.

        • Re:Heh (Score:5, Interesting)

          by Muad'Dave (255648) on Friday January 01, 2010 @07:07PM (#30616952) Homepage

          One of the key issues is having power enough to heat them in the winter.

          If the supposedly 'enlightened' greenies wouldn't raise a huge ruckus, the answer is to either alloy Gadolinium 148 into the frame or just have a block of it hanging around. It gives off a huge amount of heat, and essentially no radiation that would harm the rover (it's one of the few strong pure alpha-emitting isotopes).

          A fascinating paper [nanomedicine.com] on powering medical implants with radionuclides states:

          A ~0.2 kg block of pure Gd148 (~1 in^3) initially yields ~120 watts, sufficient in theory to meet the complete basal power needs of an entire human body for ~1 century (given suitable nucleochemical energy conversion and load buffering mechanisms, and a sufficiently well-divided structure).

          Also from that paper, an amazingly small sphere of Gd 148 can power small implants:

          Among all gamma-free alpha-only emitters with t1/2 > 10^6 sec, the highest volumetric power density is available using Gd148 (gadolinium) which a-decays directly to Sm144 (samarium), a stable rare-earth isotope. A solid sphere of pure Gd148 (~7900 kg/m3) of radius r = 95 microns surrounded by a 5-micron thick platinum shield (total device radius R = 100 microns) and a thin polished silver coating of emissivity er = 0.02 suspended in vacuo would initially maintain a constant temperature T2 (far from a surface held at T1 = 310 K) of [ 600 K ] with a 75-year half-life, initially generating 17 microwatts of thermal power which can be converted to 8 microwatts of mechanical power by a Stirling engine operating at ~50% efficiency.

          • Wow. Remember Terminator 2, when Arnold said his power core would be good for about a century? James Cameron got that scientific fact exactly correct.
          • Re: (Score:2, Funny)

            by az26er (1179135)
            In English, Carter...
          • A ~0.2 kg block of pure Gd148 (~1 in^3) initially yields ~120 watts, sufficient in theory to meet the complete basal power needs of an entire human body for ~1 century (given suitable nucleochemical energy conversion and load buffering mechanisms, and a sufficiently well-divided structure).

            So, could this also be used to power a laptop?

            Imagine a laptop battery that doesn't have to be recharged, ever.

            Sure, the cost would be greater, but imagine the savings.

            How much is the price of Gd148 anyway? :-)

            • by Muad'Dave (255648)

              That would be a great use, is you could overcome 2 issues:

              1) That block of Gd148 would be thermally VERY HOT all the time.

              2) Unless you could sequester the Gd148 in such a fashion that would render it unextractable, people would find a way to powder it and introduce it into other people's lungs/veins/digestive tracts. Alpha particles are stopped by you skin so they generally pose no threat unless they're ingested - alphas pounding away at lung tissue -- very rapid tumor development.

              Those concerns don't appl

      • If they'd done that, the rovers would have covered about 1/10 of the terrain they have due to need to plan and execute every maneuver such that not only does it not get the rovers in trouble, the the cable doesn't get snagged either. Given that Spirit and Opportunity are already at the extreme limit of what the landing system they used is capable of - you'd have rovers half the size and with [probably] less than half the science payload of the current rovers.

    • Re:Heh (Score:4, Insightful)

      by couchslug (175151) on Friday January 01, 2010 @05:48PM (#30616412)

      "You know what the solution to this problem is? Send more rovers. Lots more. If we had a spare rover near Spirit, we could probably have it roll over and give Spirit a tow..."

      We could afford to send MANY more unmanned missions (not to rescue other unmanned missions...yet) if we weren't spending a disproportionate amount of money on the romantic adventure of sending meat tourists into space. If the public want romance, let them fap to science fiction.

      We are wasting resources that could be advancing the vital robotic capabilities we REQUIRE ANYWAY to explore the universe.

      • Some people do pay to be tourists, and those who don't pay (shuttle crews) are not tourists.

        As for exploring the universe with robots, are we going to have subspace communications, or an eight-year latency with our robots near Alpha Centauri?

        • I would be thrilled to have robotic probes beaming back four-year-delayed updates from Alpha Centauri, since that is the only option that seems even remotely realistic. It's the travel time to the stars that is the problem, not the delay in your transmissions once you're there.

          Even if we could accelerate a spacecraft to an insanely fast 0.1c (at present the fastest we've managed is 0.00025c), it would take almost half a century to reach our closest neighbor (assuming it wasn't destroyed by interstellar dus

      • We could afford to send MANY more unmanned missions (not to rescue other unmanned missions...yet) if we weren't spending a disproportionate amount of money on the romantic adventure of sending meat tourists into space.

        The only engineering reason for space exploration beyond Earth's orbit is to get people off this rock and propagate the species. So, we have to know how they react in space to make this possible.

        The rest is academically curious, but ultimately not important if it doesn't help us build settle

    • Well, we could always just start sending people to Mars. Work towards setting up a research station there, have the people do two year shifts. Then, when one rolls over, somebody could just roll it back over.

      We could also, once we start sending people to Mars, figure out once and for all whether or not there is life there(bacterial or otherwise), and if there is not, we could start the terraforming process.
      • So I probably should say right now that I do realize how heavy the rovers are, and no, I don't see one person by themselves rolling it back over. It would be a team effort, or they would have machinery sent up that would be able to do the job. The whole point of the statement was that a human would be there to direct the operation on site.
        • So I probably should say right now that I do realize how heavy the rovers are, and no, I don't see one person by themselves rolling it back over.

          Hmm? The rovers weigh about 120 pounds. My daughter could roll one back over.

          Or were you thinking of their weight on Earth? Doesn't much matter that they weigh 400 pounds here....

      • by RobVB (1566105)
        As this article [slashdot.org] says, it would be much easier and much cheaper to send scientists to Mars on a one-way trip. Plenty of comments on the subject are already posted there (many of them hilarious), so I'll keep this comment short.
    • The rovers need a better arm. They should be capable of pushing themselves out of the dust or out of a rolled-over state with one arm. Some of the lunar rover designs have featured wheeled legs, each of which can articulate and also work as an arm (with the wheel twisted aside). If you had 6 articulated legs in a rover, the failure of 2 of them might be tolerable.
    • You know what the solution to this problem is? Send more rovers. Lots more.

      Why? The rovers can only answer a limited set of scientific questions and their landing systems can only reach a very small (and mostly scientifically uninteresting) portion of the planet's surface. Sending a lot of them is like hoping that, since you can't afford a car, a bunch of matchbox vehicles will serve as a useful replacement.

      If we had a spare rover near Spirit, we could probably have it roll over and give Spirit a

  • Ya gotta pin it to win it!

  • it will be nice when we can but a nautical rover in that liquid methane ocean...and not have to pay engineers to kludge their way out every hole, sandy spot, or dusty place. Also be cool if it could use the methane as a fuel source.

    • Re: (Score:3, Informative)

      by CdBee (742846)
      Wouldnt the problem be the inverse of that on earth? IE you need oxygen to do anything useful with methane in the same way you need a flammable or reactive substance to do anything useful with oxygen.. ?
    • Re: (Score:2, Troll)

      by KiloByte (825081)

      Except we humans are made to walk on ground. We know what to do when standing on something, so such a planet is of value to us.

      Bring a few guys to Mars, give them basic tools and here you go: bricks can be made from local material using 5k years old technology, then you get buildings (making them hermetic is merely tricky but not insurmountable), and it's a straight road from there.

      But people stuck in a boat on (or in) an ocean of methane? I can't see any obvious way to make such an outpost expand.

      Thus, g

      • by gandhi_2 (1108023)

        For what it's worth, i have no idea why you got marked troll. I think you made a very insightful argument.

  • Honestly.
  • by CarlDenny (415322) on Friday January 01, 2010 @05:28PM (#30616288)

    Because it was the first thing I wanted to know, Spirit's twin Opportunity is still going strong and puttering around a rock called Marqeutte Island. So regardless of how Spirit pans out, there's a really good shot at seeing year 8 of the Mars Rover 90 day mission.

    http://marsrovers.jpl.nasa.gov/mission/status_opportunity.html [nasa.gov]

  • by preaction (1526109) on Friday January 01, 2010 @05:44PM (#30616378)
    7 years ago we put together a robot designed to survive a journey off of our own planet (secured to a fireball), through the vacuum of space (oxygen-breathing life need not apply), land on another planet (falling from miles above the surface) about which little is known (and nothing about the proper tire to use in a martian dust-pit). This tiny robot was hoped to survive for 90 days. It has survived for more than 2,500 days. This tiny moment of reflection brought to you by the You Really Are Alive In A Great Period of History Foundation.
    • Re: (Score:1, Troll)

      Yes, or of over-engineering...

      Most modern structures are designed to have a finite life plus some safety margin. That's not just a trick to sell more cell phones and washing machines, it is normal engineering practice to get the right balance of cost. The FAA would even refuse to approve a wing design for an aircraft that did not have a predicted but finite life. If the design life is exceeded that can be regarded as a bonus, but often it is also considered a sign that the engineers made it too expensive /

      • by khallow (566160)

        On the other hand, maybe we could have added some useful extra sensor to the Rover, reducing its lifespan to "only" 1,000 days but providing it with a means to avoid sand traps...

        Such a sensor would not have been worthwhile since the vehicle already has sensors that are partly effective for this sort of thing and the loss of lifespan would have more than offset the risk of getting mired in the sand.

    • by bazorg (911295)
      [irish accent]Blasphemy!![/irish accent]
  • Time to smoke some tires.

    The other rover needs a winch like any respectable Range Rover would have. Sounds like a cheap fly-by-night sort of budget operation...Oh wait, it was.

    Sheldon

    • The other rover needs a winch like any respectable Range Rover would have. Sounds like a cheap fly-by-night sort of budget operation...Oh wait, it was.
      Normally I'm all for NASA bashing, and they and the mentality they represent are certainly not the way our species will get off this rock sustainably. Still, it seems kind of wrong to dump on them when we're talking about the Mars rovers, which by almost any measure was a job well done.

  • Considering how long Spirit has been stuck, it's quite amazing that the MER team keep plugging at this. Or maybe pulling the plug just doesn't occur to them. :-)

    --Greg

  • Can someone in the know indicate if/why it can not rock itself out. About 4 times/year I have to rock my car out of street parking, if I left it out and it snows 10cm.

    You would need to be able to load code to do the rock locally, and a 3d accerometer to decide when to change direction, or floor the drive as you came out.
  • With the progress they have made in the past weeks, and the problems that they had with the broken wheels (two wheels seems not be 'broken' by now), and the fact that the rover is still sinking deeper and deeper, I think I would stop the extraction process and go for getting Spirit survive the winter. It is a pitty for all the energy they invested in trying to find a safe extraction path with a spare rover here on earth, but maybe it is time to expect that the Spirit rover is stuck forever.
  • I think they are kind of clutching at straws now.
    I wish them the very best but I think I'd start taking bets on them not getting this puppy out of the sand (even if they do, how do they know it's not thicker 5' away?)
    RIP little dude.

  • Ok, people... (Score:3, Insightful)

    by rickb928 (945187) on Friday January 01, 2010 @10:26PM (#30618730) Homepage Journal

    Everyone who has a comment on how the Rovers should have been designed differenty;

    Everyone who has a comment on how the teams should have better ways to deal with this problem;

    Everyone who has a comment on how the mission could have gone better;

    Everyone who has a comment on how there must be a better way;

    Shup Up. Now.

    The 90-day mission is looing forward to its 8th YEAR. We have received data several orders of magnitude greater than hoped for. We've travelled much, much more than thought possible for thse Rovers. We've also learned a great deal about how to conduct robotic missions on other planets or moons in the solar system. We have gotten nothing short of a scientific miracle in the volume of information, learning opportunity, and pure information.

    The teams running this show have done stellar work, overcoming incredible obstacles. Amazing work.

    And your ideas about solving the current problem? As if it hasn't already been thought of, considered, even tried out in simulation.

    Read a bit of the blogs from the teams. They are pretty damned incredible.

    Me? I got no idea how to get it out of the sand. Tilting and waiting out the winter is a good plan, rather than taking chances when the Rovers are actually doing pretty well otherwise.

    Honestly. This mission is delivering value way beyond expectations. I got no complaint.

  • by Torodung (31985) on Friday January 01, 2010 @11:57PM (#30619304) Journal

    [NASA is] hunting for a way to keep the machine, which is mired in a sand trap, alive to see a seventh year.

    Ah. The real reason for Tiger Woods' leave-of-absence.

    --
    Toro

  • I have a feeling if NASA had direct and immediate view and control of the rover they could easily free it from the sand.
    They could do this by rocking it back and forth, by shifting from forward to reverse rapidly until it rocked from it's hole.

    Sort of like finding the resonant frequency of a stop sign for example, by shaking it.

    I'm sure they could find the math to support this, although it would likely be extremely complex, and need to factor in the mass of the vehicle, gravity, weight and depth of

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