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Mars Space Science

Mars Rovers Have Incorrect Instruments Installed 294

Posted by Zonk from the maybe-they-should-have-given-them-different-paint-jobs dept.
Christopher Reimer writes "The New Scientist is reporting that the twin Mars rovers, Opportunity and Spirit, has instruments installed in the wrong rovers. From the article: 'While the bungle does not undermine the main scientific conclusions drawn from the data collected by the rovers, it is an embarrassing slip-up for a space agency that once lost a Mars spacecraft because engineers mixed up metric and imperial units.'"
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Mars Rovers Have Incorrect Instruments Installed More

Mars Rovers Have Incorrect Instruments Installed

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  • Man (Score:5, Funny)

    by Anonymous Coward on Friday March 04, 2005 @11:43PM (#11850521)
    Who knew being a rocket scientist was so tough.

  • In Other News.... (Score:5, Funny)

    by TimeTraveler1884 ( 832874 ) on Friday March 04, 2005 @11:44PM (#11850524)
    Twin Mars rovers, Opportunity and Spirit landed on the Moon.

  • Subject says it all - mod me down if you have never read Mark Twain :)
    • Except, as you recall, Puddnhead Wilson was quite intelligent, and used the nascent science of fingerprinting to solve a complicated crime. His sardonic wit and odd intellectual habits led the uneducated people of the little town he moved to to assume he was a bit slow. Eventually, they concluded he wasn't just slow, he was a Puddnhead.

      From The Tragedy of Puddnhead Wilson:

      He was a homely, freckled, sandy-haired young fellow, with an intelligent blue eye that had frankness and comradeship in it and a cover

  • Confusion...Why differing configurations? (Score:3, Interesting)

    by Alpha_Traveller ( 685367 ) * on Friday March 04, 2005 @11:45PM (#11850534) Homepage Journal
    Creeping errors
    Although their designs are identical, each instrument is unique because of quirks in the materials they are made from. So before the rovers were launched, each instrument was calibrated using known rock samples. The measurements from each rover are then processed using the calibration files, but because of the mix-up, researchers were using the wrong ones. As a result, small errors have crept into the APXS results, affecting measurements of sodium, magnesium and aluminium abundance.
    Perhaps someone can clarify this statement? (Since I am not an engineer, eh?)... I'm wondering why it's so important to have differing configurations for the sensors in the first place. Wouldn't it be wise to collect exactly the same kind of information regardless of how complex if it's all being sent via transmission back to us anyway? Wouldn't it be extremely important to have the exact same configuration on BOTH sensors? I would think the end result would be useful when comparing the chemical composition of any particular area. It would be like hacking off a sensor "at the knees" when you had no significant reason to do so wouldn't it?

    • Re:Confusion...Why differing configurations? (Score:5, Informative)

      by theparanoidcynic ( 705438 ) on Friday March 04, 2005 @11:49PM (#11850548)
      It's not intentional. Building something exactly to spec is impossible. The sensors are not identical for this reason. Not really a problem when you do a proper calibration.

      Of course, it becomes a problem when you use the wrong calibration curve for the sensor.
    • The sensors are calibrated so that scientists on Earth know exactly how much of each mineral/rock there is in a sample, not just relative amounts. What I don't understand is why this is a big deal. If the sensor files are calibrated on Earth after we get the raw sensor data the people at NASA can take their old raw data and run it through the right calibrator. If the calibration is done on the rovers(which would be stupid) or they lost the raw data(stupider) they could run the data through a reverse calib
      • From the article:

        Fortunately, now that the goof-up has been spotted, it is easily fixed by reanalysing the raw data with the right calibration. Corrected values for the first year's data will be available soon, says Steve Squyres, the chief scientist for the rovers.

      • Re:Confusion...Why differing configurations? (Score:5, Insightful)

        by MillionthMonkey ( 240664 ) on Saturday March 05, 2005 @12:30AM (#11850716)
        What I don't understand is why this is a big deal.

        It isn't a big deal. Instead of "Mars Rovers Have Incorrect Instruments Installed", a better headline would have been "Mars Rover Data Analyzed With Incorrect Calibration Data Files". But the editors would have rejected a headline like that.

        It's true that the swap occurred when the instruments were installed. But it's really just a matter of semantics whether you consider the instruments to be swapped in the rovers on Mars, or their calibration files to be swapped in a computer's filesystem on Earth. Once the swap is discovered, it's over.

        • Re:Confusion...Why differing configurations? (Score:5, Insightful)

          by Aglassis ( 10161 ) on Saturday March 05, 2005 @01:07AM (#11850823)
          Small problems lead to medium sized problems which lead to big problems. Example: In the 1970's the NRC was similar to the Department of Transportation or FAA (pre 9/11) in that their job was to help facilitate the nuclear economy, not to beat down offenders. In the early 70's plant managers at a nuclear power plant in Alabamba, Browns Ferry Nuclear Power Plant, received reports that their insulation connecting to a cable room was not in accordance with fire specifications (small problem). Since this was not a significant problem, managers ignored it. Later workers testing the air-tightness of the room failed to follow the correct procedures by using candles to check the air tightness (if the flame is deflected, air is moving in that direction--small problem). Managers were aware but dismissed the problem. During testing for air leaks the flame of a candle was sucked into insulation and a fire erupted. The cable run that caught on fire was non-redundant and carried all of the control features for two nuclear reactors. Control of the reactors was lost and reactor safety was severly compromised. Problems that occured included that the operators of the reactors did not know how to properly respond to this casuality (including attempts to put out a large class A fire with portable CO2 extinguishers). Over $100 million in damages occured, but the reactors narrowly escaped tragedy (medium sized problem). This occured in 1975 and the NRC mostly covered up the problem. No congressional hearing were held. No significant corrective actions were issued and review of the ability of the operators to fight a casuality at a nuclear power plant was not reviewed. Fast forward four years and we arrive at Three Mile Island (big problem), where many of the shortcomings of the Brown's Ferry Plant and of the NRC being able to regulate and control the nuclear industry were exposed.

          The lesson to learn here: if small problems exist, dig at them to see how far you can get and then fix *all* of the problems that you uncover. There are many other examples (including the 9/11 incident) but I think the point is obvious: there are problems at JPL that are not being looked at because *nothing* happened. They should be examined and corrected prior to a medium or large problem occuring.

          • Re:Confusion...Why differing configurations? (Score:5, Insightful)

            by Laur ( 673497 ) on Saturday March 05, 2005 @02:19AM (#11851023)
            Small problems lead to medium sized problems which lead to big problems.

            No, small problems lead to no serious consequences. That's why they're called small problems. If they can lead to serious consequences then by definition they are not small problems. The magnitude of the problem is determined by the worst case scenario (Murphy's Law being what it is and all). Let's look at your example:

            In the early 70's plant managers at a nuclear power plant in Alabamba, Browns Ferry Nuclear Power Plant, received reports that their insulation connecting to a cable room was not in accordance with fire specifications (small problem).

            What is the worst case scenario if there should be a fire and the cables fail? If this is the cabling to the coffee pot, not much (small problem). If this is the cabling to the non-redundant control features of the nuclear reactor then this is a BIG problem and should have been treated as such.

            Later workers testing the air-tightness of the room failed to follow the correct procedures by using candles to check the air tightness

            What is the worst case of using this alternate procedure? In this case, there is an increased likelihood of fire. Even if the cabling was not faulty ANY fire is bad, so this should have been flagged as a BIG problem as well.

            Both of these should have been recognized as big problems and not ignored. The fault is not that small problems were ignored, it was that they were not properly classified and prioritized. It sounds like there may have been many other problems as well, but they are not related to your main point.

            The lesson to learn here: if small problems exist, dig at them to see how far you can get and then fix *all* of the problems that you uncover.

            This sounds very profound but it is a fallacy. The lesson to learn from your example is to properly classify and prioritize potential problems. It is a major waste of time and effort to address every single tiny problem which creeps up, especially in highly complex systems it is close to impossible. There are only a limited amount of resources available. You must prioritize the truly important vs the trivial or you will never accomplish anything. BTW, way to pull out the nuclear bogeyman to help make your case.

            Of course, this really has nothing to do with the NASA screw up since it really is a small problem. I doubt that the sensors were really that far off to begin with, and now that the problem has been discovered it can be 100% fixed with no loss of data. No harm no foul. Problems like this will continue to happen because everything NASA builds is a prototype! These are not mass produced items. When you build something (or write code) for the first time, is it perfect? I am also suspect of your conclusion that this problem indicates that "there are problems at JPL that are not being looked at." There may very well be problems in the bureaucracy, however this problem is indicative of nothing more than "shit happens." Of course, don't let this get in the way of a good NASA/JPL bashing.

    • Re:Confusion...Why differing configurations? (Score:5, Informative)

      by araemo ( 603185 ) on Friday March 04, 2005 @11:58PM (#11850601)
      The sensors are built and configured the same, and the raw data they collect is sent back to earth.

      However, nothing is perfect, and each sensor has slight imperfections. Before they were sent up, each sensor was measured so that those imperfections could be accounted for. This calibration data is unique to each sensor. They used the calibration data for Spirit on the data from Opportunity, and vice versa. Luckily, since they still have the original(un-corrected, raw) data, it is easy to correct.

    • Re:Confusion...Why differing configurations? (Score:5, Informative)

      by Detritus ( 11846 ) on Saturday March 05, 2005 @12:07AM (#11850637) Homepage
      Identical parts are not exact duplicates. Go to Radio Shack and buy some resistors, all marked for the same value. Take them home and measure their actual values with a multi-meter. You will find that the measured values are scattered over a range that is centered on the marked value of the resistors. That's why each resistor has a tolerance specification. For example, a resistor may be marked 47 ohms, plus or minus 5%. The value of the resistor is guaranteed to lie within that range. It isn't guaranteed to be 47 ohms. The same thing applies to capacitors, transistors, and other parts. Circuits built from these parts inherit some of the variability of their component parts.

      • Re:Confusion...Why differing configurations? (Score:5, Interesting)

        by Anonymous Coward on Saturday March 05, 2005 @12:24AM (#11850694)
        In the old days, if you bought a carbon +/-10% resistor, you could be assured that it was either -10% to -5% or +5% to +10%, and almost never in-between. The reason? They'd mark the ones that fell between as +/-5% and sell them for more moeny.

        This doesn't work for +/-5% and the next grade (+/-1%) because the parts are built differently.

    • Re:Confusion...Why differing configurations? (Score:5, Informative)

      by gilroy ( 155262 ) on Saturday March 05, 2005 @12:50AM (#11850771) Homepage Journal
      Blockquoth the poster:

      I'm wondering why it's so important to have differing configurations for the sensors in the first place.

      As a science teacher, I weep. For any instrument, it's important to perform calibration: to check the instrument against known samples, values, whatever, so that you can take the unique response of the instrument and convert it into a believable interpretation of the data. Every instrument has its own peculiarities, resulting from the (essentially unknowable) history of the construction of the instrument. Most of these features are entirely unimportant, if you know about them. So you run calibrations and figure out how to correct for the individual features.

      NASA did its job here, in that the instruments were calibrated. Yay. Then they mixed up the instruments and installed package A into rover B, meaning the calibrations were in fact wrong. Luckily they keep all the raw data, so they can simply run it through the correct calibration filter now. Double yay.

      But for all those saying "This is a small thing.": Wrong. They mixed up an entire package. Didn't it occur to anyone to actually, you know, label the two? Or to in fact make sure they weren't in the same lab at the same time? Or if that proved impossible, to keep track of which was which? Or to -- oh, I don't know -- check which package they were installing?

      Excusing this as "just a minor thing" is akin to minimizng a case where you fall asleep while driving and are awakened by the rumble strips on the side of the road. Sure, you fell asleep. But you woke up and no one was hurt. No harm, no foul, right?

      A minor screw up on its own, it still speaks volumes about NASA's continuing inability to cross all the t's and dot all the i's. And it's a pretty close relative to the error that cost us Mars Observer.

      • Re:Confusion...Why differing configurations? (Score:2, Insightful)

        by Anonymous Coward

        Excusing this as "just a minor thing" is akin to minimizng a case where you...

        Oops, you just blew up a spacecraft with that spelling error. See how easy that was?

        Unless you've tried this you have no idea how hard it is. Try designing a flight program to make sure all the i's are dotted and t's are crossed, then having the budget slashed over and over again until you can barely manufacture, test, and launch. Then try the same thing in a three-shift environment that goes on for a couple of years, and m

      • They'd want them to be in the lab at the same time, along with the baseline measurer, to make sure they were measuring the same rock under the same conditions. They'd build a rig, put baseline sensor in rig, measure, put Spirit sensor in rig, measure, etc.

        What got me is that surely you'd calibrate it after putting it in the rover. You don't calibrate something, install it, and then test it, you install it, test it, and then calibrate it. (Then test the calibration.)

        So maybe they're confused, and the probl

      • You are very right, this is NOT a little 'oopsie'. We dont like the results, but, we found if we add this fudge factor to the experimental readings, the results are more like those we wanted to get. In this case, the fudge factor is to swap the calibration files.

        Makes you wonder what happened to scientific methods, where the results drive the conclusions. I thought the case of fudging the measured data to fit the desired conclusions was limited to 'fixing' high school labs gone awry. I didn't realize

      • I disagree - it is a minor thing. As this project had a finite development budget. A Risk Analysis (RA) was performed. RA would tell you that this instance, because the "data processing" was done back here on Terra, that it made no difference which instrument was installed in which rover. Risk Mitigation would also have pointed out that it's an easily correctable problem and therefore time/money shouldn't be spent verifying it. Time would be better spent on making sure that the instruments worked. The

  • nah... (Score:5, Funny)

    by Arctic Dragon ( 647151 ) on Friday March 04, 2005 @11:46PM (#11850535)
    They instruments were installed correctly on Earth. It's the Martians that switched them as a prank. :-)

  • A very minor issue... (Score:5, Insightful)

    by Roached ( 84015 ) on Friday March 04, 2005 @11:49PM (#11850547)
    It annoys me that so much is made of this problem. This in no way compares to the lost spacecraft error, it's simply a calibration adjustment to a sensor. I think the fact that they have two rovers that have performed extremely well under harsh conditions 4x over their rated life is an incredible accomplishment. This just sounds like someone looking for sensationalism in a non-issue.

    • Re:A very minor issue... (Score:5, Insightful)

      by supabeast! ( 84658 ) on Saturday March 05, 2005 @01:36AM (#11850904)
      The reason people constantly point out problems like this is that they just keep happening in US Aerospace programs. Regardless of government agency, if you want to do anything with space in the US government, you're going to have to deal with once of a few contractors. These contractors have screwed up stuff like this dozens of times in the history of our space program, and the government keeps giving them more contracts, and never demands recompense for screwups that range from miscalibrations that can be dealt with to screwed up launch vehicles blowing up on the launchpad and taking payloads out in the process; in the former case it was an NRO satellite and the NRO hired the guy who had been running the program at Lockheed after Lockheed threw him out.

      When companies like Lockheed Martin finally have to start paying for all of their multi-billion dollar screwups in space, then this stuff will stop happening. Until then, people will continue to make a fuss because we're sick of a corrupt system allowing this crap to continue.

    • Only a minor issue because of luck (Score:5, Insightful)

      by Illserve ( 56215 ) on Saturday March 05, 2005 @02:02AM (#11850972)
      Had either of the Mars Rovers crashed or broken in some way, this mistake would never have been discovered. With only 1 rover's data, there would be no mysterious discrepency to solve and this mistake would have never been resolved.

      So scientists would have spent the next 10 years developing their theories of martian geology based on incorrect data if either one of those rovers hadn't deployed and you call this a minor issue?!

      This kind of error is inexcusable. But of course, it'll get brushed over because NASA was lucky enough to be in a position to fix it.

      • Re:Only a minor issue because of luck (Score:4, Insightful)

        by deglr6328 ( 150198 ) on Saturday March 05, 2005 @01:30PM (#11853161)
        Jeez how clueless can you get? Are people really this anal here? If you even took 5 minutes to look into this issue you'd see that it is NOT a big deal. Steve Squires himself said: "The effect in all cases was less than the uncertainties in results, so none of our science conclusions are affected,". Conclusion: it wouldn't have even affected the science appreciably if they never found out they were switched!! Also you're totally wrong when you say "Had either of the Mars Rovers crashed or broken in some way, this mistake would never have been discovered.". Hello? do you not think they took the calibration data ON EARTH? It wouldn't have mattered if either one were lost. We'd still have all the calibration data.

  • Not wrong, but swapped (Score:5, Informative)

    by dcclark ( 846336 ) on Friday March 04, 2005 @11:49PM (#11850550) Homepage
    To clarify the summary: it's not that the WRONG instruments were installed, but that the SAME instruments were installed but calibrated for the OPPOSITE rovers. So, the data have been slightly off in a predictable way. In the end, it's not too surprising nor is it devastating. The data is still valid and is being readjusted.
    • They were certainly the wrong instruments, as they are providing incorrect data.

      It is only by virtue of the luck that both Rovers are functional that NASA discovered this problem. If either one had end up dysfunctional after landing, this error would have remained uncorrected and scientists would be basing the next decade of Mars geology on incorrect measurements!

  • No big deal... (Score:5, Informative)

    by SteeldrivingJon ( 842919 ) on Friday March 04, 2005 @11:53PM (#11850576) Homepage Journal

    They're the same device on each machine, with the same function. The only problem has been that the data received has been interpreted with the wrong calibration adjustments. Swap the calibration adjustments and rerun the data, and it'll be correct.

    It would have been far worse if, say, one had a spectroscope and the other had a *drill*, and they were swapped, and each rover couldn't use the other's tool. And in that kind of a switch, it would be really bad, because the two devices would be visually distinct. But the swapping of two devices that are 99.99% identical, on two rovers that are identical, is no big thing.

    Compared to the fact that the rovers are still running long after they were expected to die, this is a tiny, tiny thing.

    • Re:No big deal... (Score:3, Insightful)

      by MBCook ( 132727 )
      It would have been far worse if...

      See, that's what I thought happened at first. I assumed it was something like one had an X-Ray detector while the other had a mass-spectrometer or something (I would think NASA could tell the difference between a drill and a spectroscope). It was nothing of the sort, they got the calibration files mixed up between the rovers (technically the rovers mixed up between the calibration files, but it's the same end result).

      This isn't journalism, this is headline mongering. Espe

    • Re:No big deal... (Score:5, Interesting)

      by Aglassis ( 10161 ) on Saturday March 05, 2005 @12:25AM (#11850696)
      "Compared to the fact that the rovers are still running long after they were expected to die, this is a tiny, tiny thing."

      Except for the fact that the same organization that made this error is designing other spacecraft. If they don't get to the root causes of the problem, like the failure of the technicians to properly follow the correct procedure to install the instrument and the failure of any other engineer or management to catch their failure to follow procedure, much larger problems could occur. Lets examine a couple of JPL's problem's in the last couple of years:

      Galileo: High power antenna failed to deploy resulting in a much lower data transfer rate. This was due to technical specifications in the lubrication of the antenna not being reviewed when the project was delayed.
      Mars Climate Orbiter: Burned up because the technical requirements were not met (converting from BES to metric).
      Mars Polar Lander: Lost on landing. Cause is not known. Project team was rushed in accordance with faster, better, cheaper plan.
      Genesis: Failed to deploy parachute and crashed on landing due to technical requirements not being met (backwards specification for G-force meters).
      Mars Exploration Rovers: Software glitch early in mission due to failure to test software for its entire expected lifespan. Instruments swapped due to failure to follow procedure.

      Some things we can get out of this analysis are that the QA was unsatisfactory. Procedures were not followed. Technical specifications were not verified. The culture was rushed (go-fever or product push environment). None of these are small problems, but they also point to much bigger problems: failure of the leadership to properly plan the project so that rushed timelines would not occur. This same culture is building new spacecraft. While JPL is a great agency and they do tremendous and incredible feats, they are not perfect and have lost several spacecraft and have had severe faults in others. These problems did not have to occur and more importantly these problems do not have to occur again in the future.

      • Re:No big deal... (Score:2, Interesting)

        by Anonymous Coward
        Mars Exploration Rovers: Software glitch early in mission due to failure to test software for its entire expected lifespan. Instruments swapped due to failure to follow procedure.

        The Trashy Fucking File System (TFFS) has bitten many projects, and the response from WindRiver is "We can't fix it." Which they can't. They bought TFFS from someone else. And they can't fix it.. for some reason. It's really a pain in the ass and the "loss of a flash file system" happens infrequently enough that it is possibl

    • Worse still if one of the rovers was lost on landing. With no frame of reference they may never have detected the initial cock up. With two at least they can contrast the measurements.

      Hedley

  • Root Cause (Score:5, Insightful)

    by Aglassis ( 10161 ) on Friday March 04, 2005 @11:55PM (#11850582)
    While the lead scientist says that it wasn't a big deal and no investigation will be held, I think he isn't analyzing the significance of this event. While scientists are more focused on the validity of data, engineers have to analyze not just events that occur (like loss of a rover), but also events that could occur. Putting the wrong instrument into a rover is due to "failure to follow procedure". This is a big deal. Failure to follow procedures could have been caught by a better QA system, better monitoring of the installation, and better training (including walkthroughs on the installation of the instruments).

    Even though this minor event that has had no impact on the mission, it has shown that there are holes in JPL's QA system, their monitoring system, and their training program for building these rovers. If you want to dig further you might find that all of these problems were caused by an unnecessary sense of urgency which may have been caused by poor project planning. These exact problems have caused the loss of spacecraft before (and many of them were cited for the loss of Challenger and Columbia).

    No investigation? The lead scientist really needs to take a look at his project management priorities. Having experience working in nuclear power I have learned and have been trained that small problems are many times the only symptoms of much larger problems. The lead scientist's attitude on the problem gives me no confidence in his ability to run a more complicated mission. Like in gambling, one or two successes doesn't mean that you are going to win on the next roll.
    • I agree completely. It's getting so bad that the best course of action could almost be to fire everyone at NASA and start over. Maybe they should pull some Apollo engineers out of retirement to act as recruiters; they at least knew how to make and follow procedures!

      • Re:Root Cause (Score:5, Insightful)

        by Detritus ( 11846 ) on Saturday March 05, 2005 @12:20AM (#11850684) Homepage
        Get over it. The Apollo era NASA had a lot more money and people. They could afford to do things the right way, with multiple backup systems and extensive testing and QA. They still made mistakes, just not as many. You want cheap space exploration? You've got cheap space exploration. Don't bitch that they didn't deliver a Ferrari when you only paid for a Chevy.
    • You can read more about root causes at http://www.taproot.com

      (official disclaimer: I work for the company, and yes please forgive the site ugliness, I'm working with a web dev as we speak)
    • Putting the wrong instrument into a rover is due to "failure to follow procedure". This is a big deal.
      Actually what is worse, is it's possible there is no procedure to follow, so it could be an even bigger issue. From my experience in commercial industry a mixup like this is a big deal, no impact doesn't mean no problem. Every little problem should have a full investigation, and should have system improvements to address it; otherwise it eventually will happen again.

    • Re:Root Cause (Score:2, Interesting)

      by notmuchtosay ( 850664 )
      Having taken a class from Squires as these rovers were being built, I know he was very aware of small problems being important. He explained how "small" problems caused failed missions in the past. Such as the previous mention of SI to imperial additionally not "testing as you fly."

      A more complicated mission? Landing two rovers utilizing air bags on another planet isn't complicated enough for you?

      He was the PI but he cannot be expected to observe everyone's work personally. This sort of thing should n

      • Re:Root Cause (Score:3, Insightful)

        by Aglassis ( 10161 )
        Squyres is quoted in the article as saying:

        "[He is] not embarrassed at all".

        "It was an easy mistake to make. It happened during some very busy and stressful times."

        The article says that he also says it is not fair to compare it to past mishaps because the spacecraft suffered no damage.

        "There isn't going to be an investigation. We know when it happened."

        He doesn't get it. The big problem here isn't that a technician goofed. The big problem is that noone caught it. The purpose of the investigation i

  • Cat calls from the cheap seats (Score:5, Interesting)

    by amightywind ( 691887 ) on Friday March 04, 2005 @11:57PM (#11850591) Journal

    Let the New Scientist criticize from the cheap seats. It is hard to argue that the rovers have been anything other than a resounding success for over 400 days. I would have hoped /. would instead print the recent story of the Spirit Rover discovering salty soil. [spaceflightnow.com]

  • Something fishy here... (Score:2, Insightful)

    by Anonymous Coward
    "There was a point when both of them were sitting on the same bench, and that has to have been it."

    Wouldn't they have been labeled, what does this have to do with anything?

  • This doesn't effect results (Score:3, Informative)

    by Monkey_Genius ( 669908 ) on Saturday March 05, 2005 @12:00AM (#11850608)
    From the JPL website: "Meanwhile, scientists are re-calibrating data from both rovers' alpha particle X-ray spectrometers. These instruments are used to assess targets' elemental composition. The sensor heads for the two instruments were switched before launch. Therefore, data that Opportunity's spectrometer has collected have been analyzed using calibration files for Spirit's, and vice-versa. Fortunately, because the sensor heads are nearly identical, the effect on the elemental abundances determined by the instruments was very small. The scientists have taken this opportunity to go back and review the results for the mission so far and re-compute using correct calibration files. "The effect in all cases was less than the uncertainties in results, so none of our science conclusions are affected," Squyres said." It would have been more serious if they had lost the calibrations on the instruments.

  • Mixed up units (Score:4, Informative)

    by eikonoklastes ( 530797 ) on Saturday March 05, 2005 @12:03AM (#11850619) Journal
    >once lost a Mars spacecraft because engineers mixed up metric and imperial units.

    I'm getting pretty tired of this sound (text?) bite the media throws out. It wasn't mixed up units; it was error accumulation from switching back and forth between the units.

    • Re:Mixed up units (Score:5, Informative)

      by DerekLyons ( 302214 ) <fairwater@@@gmail...com> on Saturday March 05, 2005 @01:14AM (#11850846) Homepage
      >once lost a Mars spacecraft because engineers mixed up metric and imperial units.

      I'm getting pretty tired of this sound (text?) bite the media throws out. It wasn't mixed up units; it was error accumulation from switching back and forth between the units.

      It's even worse when the person making the correction himself gets it wrong.

      The cause of the loss wasn't mixed up units, though they contributed. The loss was caused by ignoring a growing discrepancy between the precalculated navigation values and the actual navigation values. The errors were well within the correctable range, but for a variety of reasons the subtly different but incorrect values were ignored until it was too late to correct for them.

    • ...it was error accumulation from switching back and forth between the units.

      No, it wasn't. Yes, there was error accumulation. But the accumulation was due to a metric-english conversion factor that had been dropped during the port of the flight software from a previous program. The lack of decent documentation for the software meant that the folks assigned to do the port were unaware of the significance of the conversion factor. without the conversion factor thruster burns were executed incorrectly, resul

    • Can you cite any source that confirms this? Everything I could find says that the ground software used pound-force instead of Newtons, so the thrust was off by a factor of ~4.5. Nobody says anything about conversions taking place

    • Re:Mixed up units (Score:3, Informative)

      by FleaPlus ( 6935 )
      It wasn't mixed up units; it was error accumulation from switching back and forth between the units.

      Do you happen to have a source for that? Wikipedia says the following:

      http://en.wikipedia.org/wiki/Mars_Climate_Orbiter # The_metric_mixup [wikipedia.org]

      The Mars Climate Orbiter's reaction wheels were kept within their linear (unsaturated) range through thruster firings in a procedure called Angular Momentum Desaturation (AMD). When an AMD event occurred, relevant spacecraft data was telemetered to the ground, proces

    • Not informative, but wrong (Score:5, Informative)

      by 4lex ( 648184 ) on Saturday March 05, 2005 @06:33AM (#11851482) Homepage Journal
      Please look page 13 of this report [nasa.gov] of the NASA (las paragraph of the page):

      "On September 27, 1999, the operations navigation team consulted with the spacecraft engineers to discuss navigation discrepancies regarding velocity change (V) modeling issues. On September 29, 1999, it was discovered that the small forces V's reported by the spacecraft engineers for use in orbit determination solutions was low by a factor of 4.45 (1 pound force=4.45 Newtons) because the impulse bit data contained in the AMD file was delivered in lb-sec instead of the specified and expected units of Newton-sec."

  • Hats Off to NASA (Score:5, Insightful)

    by Orphaze ( 243436 ) on Saturday March 05, 2005 @12:09AM (#11850644) Homepage
    So, let me get this straight: NASA has managed to successfully send two completely functional rovers to the planet Mars 45 million miles away. Since they have arrived, the two rovers have expanded our understanding of the planet greatly and have had few and mostly correctable errors. They are now way, way past their expected mission time and are still running, and a few people have the nerve around to here to bash NASA for their horrible, numerous mistakes?

    This stuff isn't easy. Just because you reap the benefits of the entire space program from your living room couch via the TV without actually contributing one bit does not mean you have any understanding of how complex and spectacular these great accomplishments are.

    To the NASA / JPL engineers and scientists: Thanks.

  • In other news: (Score:5, Funny)

    by Viceice ( 462967 ) on Saturday March 05, 2005 @12:17AM (#11850671)
    A hermit writes: "The Church is reporting that the two human genders, male and female, have instruments installed in the wrong genders. From the article: 'While the bungle does not undermine the main reproductive conclusions from the reproductive activities between genders, it is an embarrassing slip-up for a supreme being that once lost a world of worshippers to a flood because the first prototypes mixed up good and evil.'"
  • Then ask yourself how many times identical twins that you've known managed to play some trick on you.

    And can we tone down the headline sensationalism a bit? You'd think the rovers have a core drill where there should be a camera or something. They somehow managed to switch two spectrometers, as identical as modern metallurgy can make them, destined for two similarly identical rovers - and now the error's been uncovered and the data recomputed. Jeesh...

  • Hit it! (Score:4, Funny)

    by dexter riley ( 556126 ) on Saturday March 05, 2005 @12:31AM (#11850720)
    Because they're rovers,
    Identical rovers, you will find...
    They look alike, they rove alike,
    They even calibrate alike!
    (Should I put this alpha-particle X-ray spectrometer in you...or you? Whoooaaaa!)
    You will lose your mind!
    When rovers...are two of a kind!

    Identical Rovers! Tuesdays at 8 on SCTV!
  • ...Again? I swear, everytime I hear news about something launched in the space, there are follow up stories about YAMUF (Yet Another Measurement Unit Farkup).

  • 'Bungle' is a bit too harsh... (Score:3, Informative)

    by Frennzy ( 730093 ) on Saturday March 05, 2005 @12:52AM (#11850775) Homepage
    Calling this oversight a bungle is a bit too harsh...for those who didn't read the article, it also says:

    their mission has been considered an unqualified success. Spirit and Opportunity provided the first irrefutable evidence that there was once liquid water on the surface of the Red Planet and are still roaming long after their scheduled 90-day mission.


    Once the mistake was realized, they could easily accomodate it through other calibration techniques. I think the parent article is trying to raise a sandstorm in an otherwise rarefied atmosphere.

  • Speaking of slipups... (Score:4, Informative)

    by fm6 ( 162816 ) on Saturday March 05, 2005 @01:07AM (#11850824) Homepage Journal
    ... because engineers mixed up metric and imperial units.
    The U.S. does not use imperial units [wikipedia.org]. We use customary units [wikipedia.org]. Many unit names are the same, but not the units themselves.

  • They should have... (Score:2, Interesting)

    by chud67 ( 690322 )
    ...put Burt Rutan in charge of the mission.
  • In further new, a NASA spokesperson announced that they had actually only sent one rover to Mars. Apparently, a last minute mixup resulted in only one rover and one Oregon Scientific WMR968 Wireless Weather Station being put into the launch craft. Researchers asked for comment claimed that "we are relieved, because this explains why all of the queries we sent Spirit returned '-34 degrees centigrate' and the accelerometer always read '10 millibars'."

  • [..]an embarrassing slip-up for a space agency that once lost a Mars spacecraft because engineers mixed up metric and imperial units.

    Which wouldn't be a problem if the US would get with the program and switch to metric. Most of the rest (if not all of the rest) of the world has already done it. I don't know how scientists and engineers there can stand having to deal with that outmoded, ridiculous imperial system.

  • ... Which is why large corporations tend to hire Quality Assurance people. It's also why development teams tend to deploy to a testing environment before launching something live.

    It's a very common concept in business, so why can't NASA seem to get it down?

    I'm sure that there are many things to double check when it comes to spacecraft, but NASA has so many of these "human error" problems all the time, it seems. They really need to hire such a group now. If there's already a QA group for the project (w
  • I imagine that's a bit like having a plural form of a verb in a sentence intended for a singular form?

  • Beagle 2 had the correct instruments installed (Score:3, Insightful)

    by tinrobot ( 314936 ) on Saturday March 05, 2005 @02:07AM (#11850986)
    ...and it proceeded to install those instuments all over the surface of mars.

    Spirit and Opportunity have performed incredibly well. These guys deserve nothing but respect.
  • You know, Compared to mixing up metric and imperial units, this seems downright intelligent of them.

  • Oops. (Score:5, Funny)

    by ktakki ( 64573 ) on Saturday March 05, 2005 @02:11AM (#11851002) Homepage Journal
    Okay, I was in the meeting where the difference in calibration was discussed, and I was the one that suggested that the instrument packages should be marked so that the right package would be installed in the right lander.

    I recommended that one package should be marked with an "O" for "Spirit" and the other with an "S" for "Opportunity". I even donated the Sharpie marker and masking tape for this purpose.

    It's not my fault that the implementation was screwed up. It's those numbnuts in the Vehicle Assembly Department who can't read a bloody memo.

    Fortunately, I've left NASA for a position at the Department of Defense. My team is tasked with identifying sites related to the constructon of weapons of mass destrucion in South Korea.

    k.

    • Re:Oops. (Score:4, Informative)

      by Dominic_Mazzoni ( 125164 ) on Saturday March 05, 2005 @05:21AM (#11851361) Homepage
      I recommended that one package should be marked with an "O" for "Spirit" and the other with an "S" for "Opportunity". I even donated the Sharpie marker and masking tape for this purpose.

      I know you were joking, but keep in mind that the names "Spirit" and "Opportunity" were chosen very late into the mission, as the result of a contest. Within JPL, the probes were known as MER-A and MER-B, and the rovers were known as MER-2 and MER-1. To make things even more confusing, for various sensible reasons they ended up putting MER-2 inside MER-A, and MER-1 inside MER-B, even though that made things more confusing.

      So, considering that they were otherwise identical, can't you see how easy it would have been to get otherwise identical parts mixed up...was it supposed to go in MER-B? Or MER-2? I just remember it was the second one of something...
  • ... the less they're worth.

  • I guess being... (Score:3, Funny)

    by Anita Coney ( 648748 ) on Saturday March 05, 2005 @08:05AM (#11851609) Homepage
    ... a rocket scientist isn't what it used to be.

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