How JPL keeps the 13-year-old Curiosity rover doing science

(spectrum.ieee.org)

211 points | by pseudolus 13 hours ago

7 comments

  • rented_mule 11 hours ago
    The total cost of Curiosity to date is well under 5% of the cost of the recent trip humans took around the moon (something like $3B vs. $90B, or $20 vs. $600 per US taxpayer). Imagine the amount of science that could get done if we gave even half the budget of crewed spaceflight to rover / probe style exploration.
    • somenameforme 2 hours ago
      The unreasonably high price is because NASA is obligated by Congress to use Boeing and their SLS. It costs orders of magnitude greater than SpaceX for no benefit whatsoever, as a Falcon Heavy could absolutely be fitted for a lunar flyby if desired. Another problem is that rovers are way more limited than most people realize.

      The fundamental problem is that moving parts break, so their design/behavior are very limited. For instance Curiosity's drill can only drill to about 6cm, and even then it broke after 16 limited activations. It then took a team of scientists around 2 years to come up with a partially effective workaround. A guy on the scene could have fixed it a few minutes, or done just as effective 'drilling' himself with a spoon. We're literally not even scratching the surface of what Mars has to offer.

      Another issue is in mobility. That involves lots of moving parts. So Curiosity tends to move around at about 0.018 mph (0.03 km/h) meaning at its average speed it'd take about 2.5 days to travel a mile. But of course that's extremely risky since you really need to make sure you don't bump into a pebble or head into a low value area. So you want human feedback on a ~40 minute round trip total latency on a low bandwidth connection - while accounting for normal working hours on Earth. So in practice Curiosity has traveled a total of just a bit more than 1 mile per year. And as might be expected its tires have also broken. So it's contemporary travel time would be even worse.

      Imagine trying to dig into all the secrets of Earth by traveling around at 1 mile per year, and once every few years (on average) being able to drill hopefully up to 6cm. And all of these things btw are bleeding edge relative to the past. The issue of moving parts break is just an unsolvable issue for now and for anytime in the foreseeable future.

    • lisper 44 minutes ago
      The space program is not about science. It has never been about science. Science is just the excuse, the window-dressing. What it's really about is military power and sending money to the right congressional districts. Source: I worked at JPL from 1988 to 2004.
    • tjchear 7 hours ago
      Presumably a common argument for sending a trained human expert in place of a robot is because a human can exercise much better judgment on what to explore and dive deep into on site, whereas doing so via a rover is subject to high latency and low bandwidth. It’d be really cool if LLM (or any AI for that matter) reaches the level of sophistication of an in the field scientist and we can send them instead of humans for 80% of the results at 10% of the cost.
      • foobarbecue 5 hours ago
        You'd probably be interested in Curiosity's AEGIS system if you aren't already aware of it.
    • thegrim33 9 hours ago
      Yes, and Curiosity weighs 899kg, whereas a single SLS launch can put 26,988kg of robots, cargo, and humans into trans-lunar orbit.
      • hparadiz 5 hours ago
        I get your point but the payload delivered to Mars was 3,893 kg. Entry/descent/landing system: aeroshell + heat shield + parachute + fueled descent stage / sky crane + Fueled Cruise Stage.
        • mitthrowaway2 2 hours ago
          That sky crane system still blows my mind. Straight out of science fiction.
    • WalterBright 2 hours ago
      Now that JPL has a design, they could crank out dozens of Curiosities and do lots of science with little more money.
    • andyjohnson0 10 hours ago
      > Curiosity [...] has traveled nearly 37 kilometers, drilled into and sampled 42 different rocks, and as of publication has snapped nearly 763,000 photos.

      Without in any way minimising the amazing scientific and engineering achievements of the team and the rover: we need crewed space exploration because people on Mars would be able to do the above in significantly less than thirteen years. Or, to put it another way, would do much more science in the same amount of time.

      • Thrymr 10 hours ago
        > much more science in the same amount of time.

        I'm not convinced by the time argument, as astronauts would have limited time on Mars dictated by orbital mechanics and return schedules, but the bigger problem is cost. You are replying to a comment about how rovers and probes are cost effective; there is no way that crewed exploration could accomplish more science than Mars rovers without orders of magnitude more cost.

        • tkcashman 9 hours ago
          A manned mission to Mars isn't even on the table yet (sorry, Elon) until we solve several huge problems, including cosmic radiation, landing heavy payloads, and a feasible alternative to chemical propulsion (most likely nuclear, but untested).
          • hugmynutus 4 hours ago
            Add to the list that martian dust contains a massive amount of carcinogens meaning any air/dust lock has to be an ISO-6 clean room.

            Sure it is a "solved" problem but all the solutions are very heavy.

            • gosub100 6 minutes ago
              This is the first time I've heard of that. What are some of the carcinogens? I know the radiation is bad there, but I didn't know the regolith was toxic.
          • ozim 8 hours ago
            Manned mission to Mars is a fad.

            But it is important fad just like space mining.

            We as humanity have to believe we are not in zero sum game to stay decent…

            Unfortunately last years are showing us how ugly it is with rare earth elements, energy etc. It is also showing what you wrote is true. No one really believes that we can affordably space mine for rare earth and no one believes in Martian colonization that would bring tangible benefits.

            • somenameforme 2 hours ago
              If you held the same logic back towards the beginning of humanity then we'd all still be wandering about the woods poking each other with sticks. Most people don't believe things are possible which is probably some sort of evolutionary thing. A society full of people with their head in the clouds probably wouldn't work so great, but humanity would also stagnate without at least some people looking to the stars.

              This could very well be why planned economies seem to struggle with innovation. People being able to devote significant resources to endeavors, that might not make sense to most, is how you get lots of failures, and the occasional revolutionary successes. Do everything by committee and all you get is a shinier version of what you had last year.

            • WalterBright 2 hours ago
              It wasn't that long ago that HN had a spirited discussion about how data centers in orbit could not possibly work. But it looks more and more like Musk is going to deliver.
            • cucumber3732842 5 hours ago
              >No one really believes that we can affordably...

              People said that about everything. I wore a $10 silk tie to work today and ate toast with a $1 Avacado on it.

              Marco Polo would shit a brick if he saw Interstate 90.

          • peterburkimsher 8 hours ago
            Not to mention supplying astronauts with food and managing their waste for 6+ months.
        • rented_mule 10 hours ago
          And if we're keeping costs proportional, send orders of magnitude more rovers and that helps the time argument for rovers as well.
        • baq 2 hours ago
          A geologist with a shovel could do 10 years of Curiosity’s science in an hour.
      • ianferrel 7 hours ago
        For the cost of sending one human there for a week, we could send thousands of robots there for years.

        There is no way that human space exploration is ever cost effective with robot space exploration.

      • II2II 7 hours ago
        Manned missions would still have constraints. In some cases, they would be far greater (e.g. due to the necessity of keeping the astronauts alive). Where there are fewer constraints, it would be intertwined with the cost of sending people to Mars. They may be able to travel faster, but a lot of that is going to be because of a larger energy budget. It is doubtful they could travel further, since there are still going to be limits on how far they could travel (humans need infrastructure). That said, perhaps they could cover a larger area (within a smaller radius) than robots. Risk is also a limiting factor, and it is a far bigger one with people. Humans may be more flexible, but you aren't going to have those romantic scenes of people scaling down steep slopes or spelunking in caves. It could be done, but the chances of something going wrong will inhibit it.

        While on the topic of human flexibility, it is important to understand that it will be limited due to the resources available. What we saw on Apollo 13 wasn't the product of people trying to expand beyond the mission objectives with what is on hand, it was a last ditch effort to save the Apollo crew. They could afford to do unintended things with the equipment on hand since the only other option was to admit defeat then let people die. Even the very much fictional The Martian was based upon that premise. Treating it as a thought experiment: the primary response was to terminate the mission and evacuate. The part about the lone survivor on Mars was about ditching every mission objective in the name of survival. It would be very difficult to even create a fictional narrative of a human team going beyond the abilities of a similarly appointed robotic mission without abandoning reality altogether.

      • 0cf8612b2e1e 8 hours ago
        Can we realistically send humans to Mars plus the return trip? I would maybe believe we can do a one way trip and leave those astronauts to die after snapping some pictures.
        • ridgeguy 3 hours ago
          I suspect there are substantial numbers of us in our 70's+ who would volunteer. Why not go out having made an amazing contribution?
          • adonovan 3 hours ago
            I'd be surprised if there's a single person alive who would volunteer for a suicide mission to a miserable cold dark planet and could travel there for nine months in a tin can through a harsh radiation/muscle atrophy/psychological environment and arrive in any condition to conduct useful scientific work.
            • WalterBright 2 hours ago
              Suppose one had a diagnosis of 1 year to live. Why not expend it doing something great?
          • WalterBright 2 hours ago
            I've been excoriated for making that suggestion.
      • jahnu 9 hours ago
        I’m no expert of course but I get the impression that we’re trying to run before we can walk. Many more robotic missions and way more basic research done more scientifically first could quite plausibly get humans there quicker in the end. Reading A City on Mars I found myself thinking this is many orders of magnitude more complicated than Apollo and will take more time.
      • gwill 7 hours ago
        sending a human there also contaminates the planet more, allowing us to learn less.
        • WalterBright 2 hours ago
          I will never understand that point of view. Mars is a lifeless rock.
    • zbendefy 11 hours ago
      Maybe we would get a microphone on mars. Just kidding i know air pressure is vastly different, but still it would be cool to listen to ambient sound from there
    • ccamrobertson 9 hours ago
      ...and further imagine the science that could be done if we mass manufactured probes rather than using experimental engineering for each one. We could have had dozens of Voyager probes in the outer reaches of our solar system by now.

      I would have loved to see more Huygens probes dropped to the surface of Titan or more New Horizons zoom past Pluto.

      I don't think human spaceflight is to blame, rather it's what connects taxpayers to space exploration as an inspirational human pursuit. But, I do agree that can be more efficient with how we spend those dollars all around.

      • WalterBright 2 hours ago
        The JWST space telescope cost $10b. I've been excoriated here by suggesting that a twin could be built probably for $1b.
    • zitterbewegung 9 hours ago
      Much easier to get a moon mission due to politics .
      • downrightmike 8 hours ago
        And they scrapped the lunar gateway to piece out the ion thrusters to send to saturn for some reason
    • colechristensen 7 hours ago
      The goal is colonization and industrialization of the moon and mars and some asteroids.

      There is only so much interest in the surface geology of the other bodies in the solar system.

    • drstewart 9 hours ago
      Suddenly HN is very pro automating human jobs with machines because it's cheaper
      • bezier-curve 8 hours ago
        The moon is probably the only celestial body humans can actually occupy with current technology, for every other object in the solar system we need robots.
        • downrightmike 8 hours ago
          Just like Hawaii, Islands require massive support and material inputs from the mainland.

          The moon is like Napoleon's exile to Saint Helena island, very remote hard to get to.

          Mars is like the antarctic, nearly all early explorers died and it take an international effort to stay down there.

    • aaron695 8 hours ago
      [dead]
  • squeedles 9 hours ago
    Was excited to hear that they have a lower power rad-hard snapdragon system going into the new missions! The RAD 750 is basically a 30-year old IBM RS-6000. Very well known, but has been the goto CPU for way longer than I thought it would be.
    • MutexMaven 4 hours ago
      Anyone who wants a more in depth look at how patches keep getting applied to what's essentially a radhard version of the candy shell Mac processors can head over to this link -> https://www-robotics.jpl.nasa.gov/media/documents/Curiosity_...

      Leveraging VxWorks you effectively have 3 different ways this software gets updated.

      Hot Patch -> Do it live! where you modify the RAM with compiled code so that the changes persist until next reboot.

      Cold Patch -> Same as a hot patch, except this time you actually copy the contents into non-volatile memory. VxWorks has a really slim profile and thus this helps keep the size manageable to continue doing science experiments.

      Full Updated -> Basically a clean install gets burned in.

    • themafia 8 hours ago
      It turns out GNC is significantly easier than rendering a video game. You don't even need that fast of a control loop. Your bigger concern is legitimate real time processing over raw compute power.

      Otherwise, we have shown, if you need power, send the astronaut up there with a laptop. Which is far easier to replace and upgrade as years advance.

  • ezst 12 hours ago
    Curiosity is a teenager now? Damn, I didn't need to feel this much older today..
    • NooneAtAll3 8 hours ago
      bepicolombo arrives on Mercury this autumn too
  • MinimalAction 11 hours ago
    I am happy to know this emblem of knowledge stream keeps coming until 2035. It is wonderful to know our innovations have flown 200 odd million miles and work for so long!
  • RedMagicBox 7 hours ago
    [dead]
  • beastman82 10 hours ago
    Jet Propulsion Laboratory, for those who are missing basic writing standards.
    • xp84 10 hours ago
      JPL has been around for over 80 years now -- I'm not sure that assuming basic familiarity with it, among people who would care about the Curiosity rover, is even a controversial choice, let alone 'substandard' writing.

      I think especially for an organization like JPL, where the name is far from a full description of what they're currently about anyway, people tend to just think of them as 'JPL' rather than how we think of, say, the United Nations.

      Edit: Also, all a reader even needs to know is what the sentence already directly implies -- that "JPL" are the ones in charge of operating Curiosity. It's like saying "How AMR Corp keeps American Airlines flying during challenging times for aviation"

      • WalterBright 2 hours ago
        It was named "Jet Propulsion Laboratory" for PR purposes, as they thought the local citizens would be concerned about a "Rocket Propulsion Laboratory" in their vicinity.
      • DharmaPolice 9 hours ago
        I do care about the Curiosity rover but I'll be honest that I only know JPL from The Martian.
    • bruckie 8 hours ago
      The first line of the article starts out "Thirteen years ago last August, I was camped out in NASA’s Jet Propulsion Laboratory press room..."
    • hatthew 7 hours ago
      Anyone not familiar with "JPL" will not be helped by spelling out "Jet Propulsion Laboratory", since it's a misnomer anyways.
  • IFC_LLC 4 hours ago
    The argument about manned vs robotic missions is kinda like a good comparison of a capybara to an orange juice.

    The guys who do those robots are real studs. 13 years on 64 megs of ram, remotely rebooting and formatting drives. One has to have a steady hand to do such operations. I can only imagine how much time, study and planning any command takes on such a mission. I'll bet they are not allowed to run a `pwd` without a full test and permission check.

    Guys who do manned missions to space stations and the moon are also epic. The same amount of prediction while being human. It's quite a show of excellence in training and study. The human won't need a new mission to Mars should he find a new type of rock. Humans can solve problems the rover was not designed to solve in the first place.

    So there will be manned and unmanned versions of those missions. Which one - is a tough question depending on myriads of factors that will be decided closer to the time when we are ready for said mission.