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Space NASA Programming Mars IT Technology

New Software Stops Mars Rover Confusion 126

Posted by Zonk from the robots-getting-smarter dept.
MattSparkes writes "The Mars rover Spirit used to get quite confused when it came upon a rock. Because it could only plan routes of a metre or two it couldn't understand how to navigate around large objects, and frequently used to rock back and forth for hours trying to figure it out. NASA have written new software called D* for the rover Opportunity, which should allow it to autonomously plan routes up to 50 metres long. The new software still won't be able to avoid sand-traps, though."
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New Software Stops Mars Rover Confusion More

New Software Stops Mars Rover Confusion

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  • The new software (Score:5, Funny)

    by Timesprout ( 579035 ) on Thursday February 22, 2007 @03:29PM (#18112228)
    actually controls the rail gun which will be used to 'eliminate' obstacles
  • ..and I can't avoid sand-traps either!

  • Based on A*? (Score:5, Interesting)

    by benhocking ( 724439 ) <benjaminhocking@nOsPAm.yahoo.com> on Thursday February 22, 2007 @03:32PM (#18112284) Homepage Journal
    I'm guessing the name is meant to suggest similarities to A* [wikipedia.org], but you think they'd mention that in the article.

    • Re: (Score:1, Informative)

      by Anonymous Coward
      You would be correct. D* stands for "Dynamic A*"

    • Re:Based on A*? (Score:5, Informative)

      by Xerotope ( 777662 ) on Thursday February 22, 2007 @03:51PM (#18112592)
      It is based on A*, in fact it stands for "Dynamic A*".

      It's designed for efficient re-planning as costs change due to information collected as the robot moves. It leverages the fact that cost updates occur close to the vehicle, so it's really only necessary to replan "locally" back to the A* path.

      That's a pretty dumbed down explanation. The original paper describing D* is here [cmu.edu].

      The actual variant being used by NASA is called "Field D*", and is able to interpolate costs and cross graph states in an arbitrary fasion (not just 8-connected).

      • Thank you: Why can't New Scientist do this? (Score:4, Insightful)

        by GuyMannDude ( 574364 ) on Thursday February 22, 2007 @04:51PM (#18113548) Journal

        Thank you for letting us know and even providing a link to the tech report.

        Here's one that that really bugs me about online news articles: they rarely take advantage of the medium! Why the hell couldn't New Scientist provide a link to this paper? As the parent mentioned, the very least they could have done would be to mention that it was related to A*. Yes, I realize that the "average reader" (whatever that means) may not want to know such details, but why couldn't they include a simple "(details...)" link right next to the mention of D*? An interested reader could click on the "details" link and expanded text would create a brand-new paragraph describing more details of the algorithm and providing a link to the tech report. Click again, and the detail paragraph collapses and you go back to reading the basic-version of the story. Simple!

        These publishers haven't grasped the power of the new media. For them, online articles simply mean that it's faster, easier, and cheaper to publish stories. Basically, they embrace web publishing for their own selfish reasons. With just a modicum of thought, they could make their products much more valuable to the consumer. But I suppose that would require them to give a damn about their work.

        GMD

        • Re: (Score:2, Insightful)

          by iminplaya ( 723125 )
          These publishers haven't grasped the power of the new media. For them, online articles simply mean that it's faster, easier, and cheaper to publish stories.

          For them, it's about entertainment and distraction, not about providing information. Entertainment is much more profitable and less labor intensive. Personally, I wish those who submit articles would link to the very original source, instead of a fluff piece from CNN.

        • Re:Thank you: Why can't New Scientist do this? (Score:4, Interesting)

          by radtea ( 464814 ) on Thursday February 22, 2007 @06:21PM (#18114976)
          Here's one that that really bugs me about online news articles: they rarely take advantage of the medium! Why the hell couldn't New Scientist provide a link to this paper?

          Because science journalists and editors know nothing about the fields they report on, and frequently seem actively hostile to the facts in favour of some made-up, mythological story.

          Some years ago a colleague at the university where I was a post-doc came into the lab and said, "Today the science section of the LA Times has five stories about stuff that I am either personally familiar with or have actually worked on. Four of them are all but unrecognizable. The fifth is full of things that are not true."

          In my subsequent experience as a scientist I have found this to be pretty much par for the course for science journalism. I don't actually know if reporters are as ignorant as they appear, but by the time the edited work gets to the reading public it is almost always spun in such a way as to be misleading or simply wrong.

          There seem to be some myths about science that are the bedrock of science reporting, and reporters or editors will distort or simply lie to ensure they reinforce those myths. Some of them are:

          1) Science is mysterious and full of contradictions (see yesterdays "hot ice" story)

          2) There is no point in anyone trying to understand science, it is beyond you (thus the lack of useful links in stories)

          3) Scientists are either put on a pedestal or dragged through the mud. They are never treated as merely ordinary people doing a job or following a vocation.

          4) The "story" is more important than the facts.

          There are probably a lot more, but basically, science journalism will never be worth anything until it starts actually reporting on science rather than wasting time promulgating editorial myths.
        • Why the hell couldn't New Scientist provide a link to this paper?

          Why would any for-profit media publisher willingly provide a means for a viewer to leave their site?

          Now, they could, as you suggested, create little "infoboxes" that expand to provide background on the topic at hand...but that requires so much more editorial effort, yet still generates no additional pageviews.

          Basically, they embrace web publishing for their own selfish reasons

          Oh, I see you got that. Sorry!

          • Re: (Score:2)

            by TheLink ( 130905 )
            Well if it's to stuff like an interesting research paper, why not? It'll make people go to their site more often, in hope to find more such papers or research. Because not all research papers at those "research paper" sites are that interesting.

            But of course they shouldn't link to another site doing the same thing they do, only better...

      • Re:Based on A*? (Score:5, Informative)

        by SnowZero ( 92219 ) on Thursday February 22, 2007 @05:08PM (#18113842)
        It amazes me how much people have picked up Field D*, given that it drops the optimality associated with A*/D*. Field D* tends to return shorter paths, but it is not guaranteed to do so. Since those were the exact reasons that groups like NASA would not touch randomized planners, I find that a little odd. I guess its the nice even upgrade path of A*->D*->Field D*. At any rate, having NASA pick up any recent work on autonomy is a success, given their conservative nature.

        I remember an Air Force person once saying they would never fund any research using any randomized algorithms; The funny thing is I managed to make a version of the randomized RRT planner the primary route planner for a UAV research project. Grids simply break down as soon as you add any sort of additional dimensions to the problem, and randomized approaches are perfect for 3D worlds and/or kinematic constraints. Personally I am a bit biased though, as I am a big proponent [cmu.edu] or randomized RRT/PRM based methods, even in low dimensions.

        Now if only game programmers would notice that there's been some advances since A*...
        • *sits up and waves* Hi, I'm an undergrad compsci, a game-programmer helpful. I've been devouring stuff on A* for months now - thanks for pointing out some advanced stuff.

      • Re: (Score:3, Interesting)

        by Anonymous Coward
        I've implemented D*, and while more efficient than A* replanning from scratch in terms of heap percolates, the overhead of D* bookkeeping actually made it slower than just rerunning a tuned A* implementation, with the caveat that this was on maps that I generated; I'm sure one can generate a pathological terrain that would erase the difference. The massive reduction in heap percolates is interesting from a computer science perspective, but in my experience, in the real world D* doesn't really give you new c

    • Re:Based on A*? (Score:5, Funny)

      by Xerotope ( 777662 ) on Thursday February 22, 2007 @03:55PM (#18112646)
      P.S. The asterisk is because the algorithm is on steroids.

    • Re: (Score:1)

      by Leuf ( 918654 )

      That's what I was thinking, and then I went on to thinking how these rovers can have been running around up there for three years without an algorithm that's been around since the 60s. I can understand being conservative about how much autonomy to give the rover at the start, but they could have three years worth of data on what the robot thought would have been a good path to review.

      And as a side note, they left the rover stuck in front of a rock for an hour and a half? Was everyone playing counterstrik

      • Re: (Score:1)

        by Cctoide ( 923843 )
        They were busy figuring out how to wallhack so they could apply the same approach to the rover issue.
      • When Mars is at its furthest from us it only takes 21 minutes to receive a signal from the rover. (And, yes, I know it's blocked by the Sun then.) That's 42 minutes round-trip. I guess one explanation is that their first attempt failed and they didn't find out until 42 minutes later. (Alternatively, and more likely, their first X attempts failed and Mars was closer.)

      • Re: (Score:3, Informative)

        by mollymoo ( 202721 )

        And as a side note, they left the rover stuck in front of a rock for an hour and a half? Was everyone playing counterstrike or something?

        Originally, they had teams working Martian days round-the-clock. But they they stopped doing that years ago now as they don't have the cash or the staff to do it any more. Months of working out-of-synch with Earth days kinda screwed with people's heads too. Even when they were doing it, they weren't in constant contact. Did you think Nasa's Deep Space Network has one of

        • Re: (Score:1)

          by Leuf ( 918654 )

          Well then I would have expected that the improvements to the rovers ability to navigate to have happened at about the same time its responsibility for its own navigation was increased. Preferrably beforehand so someone would be looking over its shoulder.

          And yeah, I did kind of figure that if we went to the trouble of putting a rover on mars that we might bother to keep a dish pointed at it all the time. When we send people there is it going to be too much trouble too? "Sorry Bob, didn't mean to keep you

          • And yeah, I did kind of figure that if we went to the trouble of putting a rover on mars that we might bother to keep a dish pointed at it all the time. When we send people there is it going to be too much trouble too?
            We need more dishes, they're busy [nasa.gov]

          • Well then I would have expected that the improvements to the rovers ability to navigate to have happened at about the same time its responsibility for its own navigation was increased. Preferrably beforehand so someone would be looking over its shoulder.

            The reduction in staffing came well into the extended mission, which means it wasn't part of the original planning. The enhanced software simply didn't exist at the time, because nobody (at least nobody who controlled a budget) though it likely the missio

      • Re: (Score:1)

        by devitto ( 230479 )
        Hey, trust me, a rover is just like a young and adventure-hungry student - too much autonomy is a bad thing.

        The last thing we want when we finally get to the red planet, is some pregnant Martian holding a picture of 'opportunity' and saying "Is this your son?"

        And didn't you go to the movies in the 60s, 70s or early 80s?
        Autonomous computers *always* kill people and attempt to take over the world. Those films pretty much all died out when MS-DOS got released.

  • Rover Still Hates Mars Though (Score:3, Funny)

    by s31523 ( 926314 ) on Thursday February 22, 2007 @03:34PM (#18112320)
    They fixed the navigation issue, but I bet the rover still hates Mars [theonion.com].

  • metres (Score:4, Funny)

    by lucabrasi999 ( 585141 ) on Thursday February 22, 2007 @03:35PM (#18112338) Journal
    You know, NASA sometimes has a hard time figuring out the difference between Meters and Miles. Now, you are asking them to figure out the difference between Metres and Meters.
  • but I have to wonder why they didn't send it up there with the ability to plane long and short treks?

    The more I learn about (semi)autonomous robotics, the more impressed I am with what the Mars rovers have accomplished already and the people who built/maintain/program them.

    My forays into hobby robotics tells me that this isn't as easy as it first appears it might be.

    • Re: (Score:3, Insightful)

      by eln ( 21727 )
      Maybe the path they had originally intended the rover to explore did not involve going around any large objects? Remember, these things were originally designed to last only 90 days.

      Had they known the Rovers would last this long, they probably would have put instrumentation on them capable of detecting things other than water (like the instrumentation that was on the ill-fated Beagle 2) in addition to more sophisticated navigation software.

      • But then perhaps, they'd be so much more complicated that they'd only have lasted the requisite 90 days...

    • Re:This is pretty impressive.... (Score:5, Informative)

      by Iron Condor ( 964856 ) on Thursday February 22, 2007 @03:56PM (#18112652)

      but I have to wonder why they didn't send it up there with the ability to plane long and short treks?

      Because they were originally intended to last for 90 days. There were no "long treks" planned. People assumed that maybe they'd survive a teensy bit beyond the 90 day mark and there was pretty wild celebration (for a bunch of nerds) at the 100-day mark because people thought it was really cool. Now, a thousand+ days later, these little guys are still going strong.

      This kind of engineering quality is the reason why JPL is the only organization on the planet that has ever sent enything past Mars orbit. They're considerably more expensive as just farming out your hardware to Lockheed (ahem), but instead of crashing into things they actually land and work properly.

      • Re: (Score:3, Insightful)

        by zappepcs ( 820751 )
        I'd agree with you, but the chance that the lander would land close to an object that is 'large' is too great a possibility to not have accounted for it? When writing code, you should always look to trap or overcome any circumstances that might confuse/cripple/kill your program. The same goes for autonomous vehicles.

        As an example, hobby robotics poses a simple problem that is very much like the one the rovers face: how to run around the house all day and "not get stuck behind the couch" with limited sensory

        • Re: (Score:3, Informative)

          by Rei ( 128717 )
          The rovers can be manually commanded to perform specific driving maneuvers (and the beginning of each drive usually is done by manual planning). It's not a problem.
      • Pioneer 10 & 11 came out of Nasa Ames.

      • Re: (Score:1)

        by joh ( 27088 )

        Because they were originally intended to last for 90 days. There were no "long treks" planned. People assumed that maybe they'd survive a teensy bit beyond the 90 day mark and there was pretty wild celebration (for a bunch of nerds) at the 100-day mark because people thought it was really cool.

        That's plain wrong. The engineers knew very well that the rovers would be good for much more than 90 days (if they weren't particularly unlucky). The mission was limited for 90 days initially for a bunch of reasons,

      • Re: (Score:2)

        by joeljkp ( 254783 )
        Don't forget APL [jhuapl.edu]. They're on their way to Mercury (further distance than Mars and with a harsher climate as well).

    • Re: (Score:2, Interesting)

      by jeffeb3 ( 1036434 )
      "My forays into hobby robotics tells me that this isn't as easy as it first appears it might be."

      Thank you. I program autonomous vehicles, and people sort of stare at me blankly when I tell them I've spent the last few months of my life trying to detect the color of a traffic light. People often take for granted their ability to sense the world around them. I can assure you, robots do not take that for granted...
      • Here here!
        I know the kind of pain that you are talking about. Most people think that things just naturally travel in a straight line too!!!! sigh
  • Every time it would figure out a way around the rock, Marvin would move the rock.

    Ha!

  • Stupid AI. (Score:3, Insightful)

    by Prof.Phreak ( 584152 ) on Thursday February 22, 2007 @03:38PM (#18112376) Homepage
    This story is a perfect illustration how stupid the current generation of state-of-the-art AI is (or lack of).

    Anyone who ever said `there aren't any opportunities in IT', try to solve this problem!
    • Not really. The mars rovers are engineered very conservatively. Whatever they're uploading to the rover was probably done here on earth 20 years ago.

    • Re: (Score:2)

      by dedazo ( 737510 )
      In his book Cosmos, Carl Sagan theorized - as part of a reflection on human evolution - that the original Viking [nasa.gov] landers were about as smart as a grasshopper. Accounting for Moore's law and whatnot you'd think they'd be able to do a lot more (though of course the Viking landers were static) nowadays.

      Still, as others have pointed out, the rover was designed to last 3-4 months. All things considered the fact that they're still going and they can be patched with new software is pretty impressive.

      We're stil

      • Re: (Score:2)

        by Dunbal ( 464142 )
        the original Viking landers were about as smart as a grasshopper.

              With all due respect to Dr. Sagan, but I disagree. Grasshoppers can find their own food and mates. They can recognize danger, and know how to respond to get to safety. The viking landers (and most "AI" nowadays) is STILL far dumber than even the most primitive insects. We still have a LONG way to go.

    • Re: (Score:2)

      by SnowZero ( 92219 )
      Look at my robots [youtube.com] and tell me they are dumb. NASA is not state of the art, they are very conservative. That's not always a bad thing when your robot is worth many millions of dollars and is halfway across the solar system. However, don't think that people aren't doing research now for NASA to use in 2020.
      • Holy Christmas! Those are very impressive! Is the a site with more details of their construction?
  • Well if its taken this long for NASA to figure out a good routine for pathing then I suppose I shouldn't be so down on Obsidian for pathing being so terrible at it with your henchmen in NWN 2.

    Is anybody else amazed at the apparent simplicity of a lot of the problems facing the rover? I don't say this to criticize the NASA guys and gals, I'm sure if I had designed a rover would never have done as well up on Mars as theirs, but it always surprises me how simple a lot of the problems they face seemingly are.

    • Re: (Score:1)

      by Chysn ( 898420 )
      The rovers were probably outfitted with "good enough" software for their expected life span of three months. The rovers' durability up there is just astonishing, and I find it pretty impressive that they can still teach it new tricks a few years later from way up here on earth.

    • Re: (Score:3, Interesting)

      by drinkypoo ( 153816 )

      Is anybody else amazed at the apparent simplicity of a lot of the problems facing the rover?

      Pathing in a video game is (by comparison) easy because you don't have to translate into the real world.

      Think about what goes into pathing in the real world for a moment. You have to consider the terrain you're crossing and anything else that might get in your way. You have to be able to revise your model intelligently as you get closer to things and get new sensor data. The whole problem is immensely complex.

      In a

  • as the Rover left its pitching wedge back at Canaveral.
  • The fact that these rovers are still working far beyond the length of time they were intended to last is remarkable in itself. That they can still be programmed to change their routine is something I find remarkable. Yes, they are simple tasks, but it is still quite an achievement.
  • Game maker Ubisoft has filed a lawsuit against NASA, claiming it stole code originally used to control GRAW AI teammates for use in the Mars Spirit Rover.
  • The new software still won't be able to avoid sand-traps, though."

    Tiger recommeded a 7 iron; get him a copy of the Rover SDK...

  • Duh, it converts the rover into a router so mars doesn't blow through it's IP space. See the earlier story on the intraplanetnet...

  • Geology vs. software development (Score:3, Interesting)

    by heroine ( 1220 ) on Thursday February 22, 2007 @04:15PM (#18112942) Homepage
    It seems since the first year, the rovers have been more useful as a means of testing robotics software than as a means of studying geology.
    • Thats an intresting point, and it reminds me about the first moon mission.
      As they wanted to the moon they choosed some military trained astronauts.
      And then in the end it was thought well that they should do * someting * there, (but what?).
      So then they got a speed training in geology... :))
      As it was mostly a space race to be there first, wich was an achievement in a technical way.

      A lot these days is still a space race (or fund race) i think.
      The actualy research is not that high prio.
      Who else wants to put peo

  • meters?? (Score:3, Funny)

    by drDugan ( 219551 ) * on Thursday February 22, 2007 @04:16PM (#18112966) Homepage
    Some NASA software engineer reading slashdot is probably shitting his pants right now because he wrote the config line:

    MAXSEARCHLENGTH: 50 yards

  • Letter from lander (Score:3, Funny)

    by edwardpickman ( 965122 ) on Thursday February 22, 2007 @04:19PM (#18113006)
    "Can I come home now? When I agreed to go to Mars I was told it was a tropical paradise and I would only have to stay for three months. It's cold and dry and I haven't seen a single palm tree, not one! The software update was a big help but I'd rather have a ticket home." Signed Spirit Rover. "I miss you guys. By the way who won the last three American Idols? Reception sucks up here."

  • God this is painful (Score:5, Informative)

    by Cally ( 10873 ) on Thursday February 22, 2007 @04:23PM (#18113070) Homepage
    ...painful to read this mish-mash of half-truths and inaccuracies...

    Yes, D* has been used "live" for the first time.

    However, both rovers received a fresh load of mission s/w a couple of months back which enables a variety of fabulous new functions, including "go and touch" (as opposed to the original "touch and go") - go and touch enables the drive planners to instruct the rovers "move 12.4 metres forwards, turn 30* left, forward 70cm, approach the rock in front of you, deploy the IDD (robot arm holding a variety of instruments, spectrometer, close up camera, the RAT (grinder) and brush, etc; deploy the Mossbauer spectrometer, take reading in situ for 18 hours".

    It also enables them to build their own route maps. One problem is that on featureless plains, it needs landmarks to assess how far it's travelled -- thus the newly developed "drunken sailor [exploratorium.edu]" manouever, designed to make clearly visible tracks that can be used to triangulate the on-board navcom. thing.

  • for (appropriately-named) OnStar, this is it! "Hey, there's a huge rock in front of me, how do I get out?"
  • This 'information' was 'officially' released November, 2006. All technical and stuff, bristling with pride about Spirit's 'new' abilities thanks to software 'D'. I'm left wondering how they got onto Mars with such rudimentary navigation in the first place, but NASA explained that due to the 20 minute lag, both rovers weren't allowed to map out more than a meter or two, and this somehow led to a 1.5 hour stutter-shuffle or something that meant they were simply not equipped to handle large objects. Was there
    • 2004 press release [nasa.gov]

      2006 press release - Sol 1014 [nasa.gov] - (four months prior to being front-burner'd by the ever vigilant staff here @ /. , no less - sigh).
    • Really? That's funny - I'm not the source of the two conflicting articles...surely you can find better ways of showing your ignorance than simply killing the messenger. In any case, you want to waste mod points, fire away.

      Karma: STILL Excellent!
      • There are a couple of things you aren't supposed to criticize on Slashdot. NASA is one of them. Linux is the other. Besides, it's best to be patient about such things ... if your commentary is worth the points someone will come along and fix it.
  • The new software still won't be able to avoid sand-traps, though."
    Guess they won't be playing much golf.

  • and frequently used to rock back and forth for hours trying to figure it out
    Is there anything on this sit that doesn't claim to be autistic?

  • The Mars rover Spirit used to get quite confused when it came upon a rock.
    Same thing happens to me when I come upon a door or other obstacle after a long Friday night at the local watering hole. Is the software OSS? I'd love to get a copy for these occasions.
  • From the article: By angling a little bit to the right early on, the rover avoided the obstacle without needing to back up or make any sharp turns. Everyone worries that the skies will become a deathtrap when flying cars, driven by people without pilots' licenses, hit the market. But the collision-avoidance solution is simple if they're all flying autonomously. In 2007, it's trivial for inexpensive consumer devices to communicate with each other wirelessly. Similarly, flying cars need to broadcast their

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