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>>>...Then thrusters, designed to decelerate the craft for 30 seconds until it was metres off the ground, engaged for only around 3 seconds before they were com

>>>...Then thrusters, designed to decelerate the craft for 30 seconds until it was metres off the ground, engaged for only around 3 seconds before they were commanded to switch off, because the lander's computer thought it was on the ground... >>...The lander even switched on its suite of instruments, ready to record Mars’s weather and electrical field... It's a shame. But, reading that, I can't help imagining the lander in the role of the Blue Whale from Hitchhiker's Guide to the Galaxy: "I wonder what this big flat thing rushing toward me is? I think I'll call it 'The Ground'"

mhandley 10y ago
Given the history of ESA landers, the more appropriate quote might be "Oh no, not again!"
- zymhan 10y ago
  It really puts into perspective what good job NASA does at what many call a "boring" mission.
  - xenobioticants 10y ago
    Considering NASA has a budget thats 3-4x that of ESA, I'd be a little less quick to judge if I were you.
    - privong 10y ago
      > Considering NASA has a budget thats 3-4x that of ESA, I'd be a little less quick to judge if I were you. I don't think GP was judging ESA. I think they were merely pointing out how impressive NASA's success rate has been lately.
      - xenobioticants 10y ago
        Truth, its especially commendable that most of their projects keep soldiering on well past EOL.
        ghaff 10y ago
        Not to take away from that but I suspect that there are a lot of good reasons to underpromise and overdeliver. I also wonder to what degree budgeting has something to do with it. Budget for a shorter lifetime given that you can usually end up extending missions if the equipment is still operational.
        rtkwe 10y ago
        Not to take away from the great work of NASA engineers but EOL is kind of a misleading term when it comes to space science missions. At lot of mission end times are based off of funding and the lowest level science goals of the mission. While those are being completed they gather a case for continuing the mission and usually get it. Of course the main cost is getting the stuff there in the first place so why not add a relatively small amount to make it last?
        zymhan 10y ago
        No, but given the short lifespan of these things due to radiation, literally other-wordly conditions, and the fact that you can never repair it, the fact that a rover on Mars can last a decade is a technical marvel. You also have to pre-program the entire flight and find out half an hour later if your parachutes and retro-rockets deployed, or you made a relatively small crater.
    - dingaling 10y ago
      Fair enough. How about the UK's Open University that was marginally more successful with Beagle 2 for £66 million. It went riding on another orbiter, Mars Express, but at least reached the surface intact.
    - ceejayoz 10y ago
      They're spending 1.4B on the two ExoMars missions (and that's not counting the Proton rockets, which Russia's contributing). NASA's budget is larger, but they're doing more missions (and spending a lot on SLS and James Webb). I suspect blaming the ExoMars crash on budget is inaccurate.
  - panglott 10y ago
    It seems like ExoMars spent years shopping around between the US and Russia for launch, and major budget problems, which caused it to be redesigned more than once. I guess NASA doesn't usually have problems like that? https://en.wikipedia.org/wiki/ExoMars#History https://en.wikipedia.org/wiki/ExoMars#History
  - rootbear 10y ago
    NASA's Mars Polar Impacter, er, Lander, also shut off it's descent engine too early, believing it was on the ground, and slammed into Mars. This stuff is hard. The Wikipedia entry gives the details: https://en.wikipedia.org/wiki/Mars_Polar_Lander#Landing_attempt https://en.wikipedia.org/wiki/Mars_Polar_Lander#Landing_atte...
    - ge96 10y ago
      They don't have altimeter's/range finders? I wonder what causes the confusion.
      - generj 10y ago
        They do have radar altimeters, but radar altimeters face occasional issues. So they usually also bake in various failsafe measures. Sadly the failsafe measures tend to be the thing which dooms spacecraft, usually in odd ways unpredictable until an actual spacecraft is hurtling towards the ground.
        ge96 10y ago
        That is too bad. I wonder if a laser in the front would be useless as the heat build up as it enters the atmosphere would make the "bounce-back" hard to receive.
  - DocTomoe 10y ago
    I think a space program that has lost a Mars-bound spacecraft because different engineering teams could not decide on if they are to use metric or imperial units of measurement has nothing to gloat about.
    - TylerH 10y ago
      It's not gloating, it's just pointing out that ESA has failed repeatedly where NASA has had repeated success. No need to take it personally.
Fiahil 10y ago
At least it wasn't a unit-conversion problem. It would be really shameful for an _European_ lander to mix up an altitude reading between feet and meters. But it's not the case, isn't it?
- etatoby 10y ago
  It may very well be. Maybe they used an US-developed microcontroller library and screwed up the unit setting.
  - cordite 10y ago
    How realistic is a dry run via an earth simulation from high aptitude to make sure units are sane?
    - hguant 10y ago
      Given that Mar's atmosphere masses about 25 terratonnes compared to Earth's 5148 terratonnes, and Mar's atmospheric pressure is about 1% that of Earth's sea level, you'd need to do high altitude testing at about 30 miles up, which is about 5 Mount Everests. Much simpler to test fire the engines in a lab somewhere to make sure they run, and test the software in a simulation of the landing. It'll probably come out in the next year or so that there was either just a flat error in the code, or that the simulation was incorrect in some way.
- zymhan 10y ago
  Surely in 2016 no one is using imperial units as a default for anything even remotely related to aerospace programming.
  - deleted 10y ago
    [deleted]
  - rootbear 10y ago
    I work at NASA and sadly, we do still use Imperial units for many things. It's a travesty.
zer0gravity 10y ago
It's very strange because, if would have been a glitch that would cause the program to halt unexpectadly, the engines would have remained running. But from the data, it actually entered into "on the ground" state initiating its exploratory procedure. But what kind of "on the ground" test condition could have made it to do that ? The fact that it was "designed to decelerate the craft for 30 seconds until it was metres off the ground" but instead it ran only 3, raises many questions. Not to say that there are zillions of ways to actually test that you are on the ground or not..
- planteen 10y ago
  > if would have been a glitch that would cause the program to halt unexpectadly, the engines would have remained running I don't know about that. I've worked on systems where there is some hardware with thruster duration that software is writing. So if software crashes, the thrusters stop. (But I have never worked on a lander). If software is running the control loop, things would get very bad if the engines kept running at their previous output levels for 27 seconds. Thrusters are never aligned perfectly, who knows what kind of rate the lander had, there may be wind pushing it, etc. If a thruster blindly kept running, the lander may have spun up, flipped over, etc.
  - zer0gravity 10y ago
    Ok, good point. But the point that I wanted to make is that a software crash wouldn't explain why the lander behaved as if it was on the ground. So it's more probable that it reached the "on the ground" condition. If that condition was adequately programmed, the chances that some sensor glitch could have triggered it are quite low. So the probability is higher that it was either badly programmed or maybe someone flipped a bit somewhere ..
    - planteen 10y ago
      Yeah I agree, it seems like that between an accelerometer and gyro that it should be fairly clear when you reach the ground condition. Maybe a switches that engages when a lander legs are pressed or something similar as well.
cyberferret 10y ago
Don't most landers have a mechanical probe extending down from the landing gear to indicate contact with ground? I wonder if this lander was so equipped? Unless they used a ground proximity radar which sent back false pings due to overheating caused by the too early discarded heat shield? I'll wait for the final crash analysis and report, but I trust that the lessons learned here will significantly improve the chances of future missions, if at least by adding some more redundancies into the mix.
- rootbear 10y ago
  See my post above about a similar NASA incident. The ground contact in that case was indicated by sensors on the landing gear. They appear to have recorded a false positive when the gear were deployed. Different spacecraft use different methods, I don't know what technology Schiaparelli used.

mhandley 10y ago

Given the history of ESA landers, the more appropriate quote might be "Oh no, not again!"

zymhan 10y ago
It really puts into perspective what good job NASA does at what many call a "boring" mission.
- xenobioticants 10y ago
  Considering NASA has a budget thats 3-4x that of ESA, I'd be a little less quick to judge if I were you.
  - privong 10y ago
    > Considering NASA has a budget thats 3-4x that of ESA, I'd be a little less quick to judge if I were you. I don't think GP was judging ESA. I think they were merely pointing out how impressive NASA's success rate has been lately.
    - xenobioticants 10y ago
      Truth, its especially commendable that most of their projects keep soldiering on well past EOL.
      - ghaff 10y ago
        Not to take away from that but I suspect that there are a lot of good reasons to underpromise and overdeliver. I also wonder to what degree budgeting has something to do with it. Budget for a shorter lifetime given that you can usually end up extending missions if the equipment is still operational.
      - rtkwe 10y ago
        Not to take away from the great work of NASA engineers but EOL is kind of a misleading term when it comes to space science missions. At lot of mission end times are based off of funding and the lowest level science goals of the mission. While those are being completed they gather a case for continuing the mission and usually get it. Of course the main cost is getting the stuff there in the first place so why not add a relatively small amount to make it last?
        zymhan 10y ago
        No, but given the short lifespan of these things due to radiation, literally other-wordly conditions, and the fact that you can never repair it, the fact that a rover on Mars can last a decade is a technical marvel. You also have to pre-program the entire flight and find out half an hour later if your parachutes and retro-rockets deployed, or you made a relatively small crater.
  - dingaling 10y ago
    Fair enough. How about the UK's Open University that was marginally more successful with Beagle 2 for £66 million. It went riding on another orbiter, Mars Express, but at least reached the surface intact.
  - ceejayoz 10y ago
    They're spending 1.4B on the two ExoMars missions (and that's not counting the Proton rockets, which Russia's contributing). NASA's budget is larger, but they're doing more missions (and spending a lot on SLS and James Webb). I suspect blaming the ExoMars crash on budget is inaccurate.
- panglott 10y ago
  It seems like ExoMars spent years shopping around between the US and Russia for launch, and major budget problems, which caused it to be redesigned more than once. I guess NASA doesn't usually have problems like that? https://en.wikipedia.org/wiki/ExoMars#History https://en.wikipedia.org/wiki/ExoMars#History
- rootbear 10y ago
  NASA's Mars Polar Impacter, er, Lander, also shut off it's descent engine too early, believing it was on the ground, and slammed into Mars. This stuff is hard. The Wikipedia entry gives the details: https://en.wikipedia.org/wiki/Mars_Polar_Lander#Landing_attempt https://en.wikipedia.org/wiki/Mars_Polar_Lander#Landing_atte...
  - ge96 10y ago
    They don't have altimeter's/range finders? I wonder what causes the confusion.
    - generj 10y ago
      They do have radar altimeters, but radar altimeters face occasional issues. So they usually also bake in various failsafe measures. Sadly the failsafe measures tend to be the thing which dooms spacecraft, usually in odd ways unpredictable until an actual spacecraft is hurtling towards the ground.
      - ge96 10y ago
        That is too bad. I wonder if a laser in the front would be useless as the heat build up as it enters the atmosphere would make the "bounce-back" hard to receive.
- DocTomoe 10y ago
  I think a space program that has lost a Mars-bound spacecraft because different engineering teams could not decide on if they are to use metric or imperial units of measurement has nothing to gloat about.
  - TylerH 10y ago
    It's not gloating, it's just pointing out that ESA has failed repeatedly where NASA has had repeated success. No need to take it personally.

Fiahil 10y ago

At least it wasn't a unit-conversion problem. It would be really shameful for an _European_ lander to mix up an altitude reading between feet and meters. But it's not the case, isn't it?

etatoby 10y ago
It may very well be. Maybe they used an US-developed microcontroller library and screwed up the unit setting.
- cordite 10y ago
  How realistic is a dry run via an earth simulation from high aptitude to make sure units are sane?
  - hguant 10y ago
    Given that Mar's atmosphere masses about 25 terratonnes compared to Earth's 5148 terratonnes, and Mar's atmospheric pressure is about 1% that of Earth's sea level, you'd need to do high altitude testing at about 30 miles up, which is about 5 Mount Everests. Much simpler to test fire the engines in a lab somewhere to make sure they run, and test the software in a simulation of the landing. It'll probably come out in the next year or so that there was either just a flat error in the code, or that the simulation was incorrect in some way.
zymhan 10y ago
Surely in 2016 no one is using imperial units as a default for anything even remotely related to aerospace programming.
- deleted 10y ago
  [deleted]
- rootbear 10y ago
  I work at NASA and sadly, we do still use Imperial units for many things. It's a travesty.

zer0gravity 10y ago

It's very strange because, if would have been a glitch that would cause the program to halt unexpectadly, the engines would have remained running. But from the data, it actually entered into "on the ground" state initiating its exploratory procedure. But what kind of "on the ground" test condition could have made it to do that ? The fact that it was "designed to decelerate the craft for 30 seconds until it was metres off the ground" but instead it ran only 3, raises many questions. Not to say that there are zillions of ways to actually test that you are on the ground or not..

planteen 10y ago
> if would have been a glitch that would cause the program to halt unexpectadly, the engines would have remained running I don't know about that. I've worked on systems where there is some hardware with thruster duration that software is writing. So if software crashes, the thrusters stop. (But I have never worked on a lander). If software is running the control loop, things would get very bad if the engines kept running at their previous output levels for 27 seconds. Thrusters are never aligned perfectly, who knows what kind of rate the lander had, there may be wind pushing it, etc. If a thruster blindly kept running, the lander may have spun up, flipped over, etc.
- zer0gravity 10y ago
  Ok, good point. But the point that I wanted to make is that a software crash wouldn't explain why the lander behaved as if it was on the ground. So it's more probable that it reached the "on the ground" condition. If that condition was adequately programmed, the chances that some sensor glitch could have triggered it are quite low. So the probability is higher that it was either badly programmed or maybe someone flipped a bit somewhere ..
  - planteen 10y ago
    Yeah I agree, it seems like that between an accelerometer and gyro that it should be fairly clear when you reach the ground condition. Maybe a switches that engages when a lander legs are pressed or something similar as well.

cyberferret 10y ago

Don't most landers have a mechanical probe extending down from the landing gear to indicate contact with ground? I wonder if this lander was so equipped? Unless they used a ground proximity radar which sent back false pings due to overheating caused by the too early discarded heat shield? I'll wait for the final crash analysis and report, but I trust that the lessons learned here will significantly improve the chances of future missions, if at least by adding some more redundancies into the mix.

rootbear 10y ago
See my post above about a similar NASA incident. The ground contact in that case was indicated by sensors on the landing gear. They appear to have recorded a false positive when the gear were deployed. Different spacecraft use different methods, I don't know what technology Schiaparelli used.