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

spectrum.ieee.org

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

#41

Post by MutexMaven »

squeedles wrote: post #15

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.

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.

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

#42

Post by IFC_LLC »

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.

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

#43

Post by hugmynutus »

tkcashman wrote: post #13
Thrymr wrote: post #11

Earlier quoted context omitted.

> 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…

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).

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.

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

#44

Post by ridgeguy »

0cf8612b2e1e wrote: post #26
andyjohnson0 wrote: post #9

Earlier quoted context omitted.

> 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,…

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.

I suspect there are substantial numbers of us in our 70's+ who would volunteer. Why not go out having made an amazing contribution?

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

#45

Post by adonovan »

ridgeguy wrote: post #44
0cf8612b2e1e wrote: post #26

Earlier quoted context omitted.

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.

I suspect there are substantial numbers of us in our 70's+ who would volunteer. Why not go out having made an amazing contribution?

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.

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

#46

Post by mitthrowaway2 »

hparadiz wrote: post #38
thegrim33 wrote: post #14

Earlier quoted context omitted.

Yes, and Curiosity weighs 899kg, whereas a single SLS launch can put 26,988kg of robots, cargo, and humans into trans-lunar orbit.

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.

That sky crane system still blows my mind. Straight out of science fiction.

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

#47

Post by baq »

Thrymr wrote: post #11
andyjohnson0 wrote: post #9

Earlier quoted context omitted.

> 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,…

> 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…

A geologist with a shovel could do 10 years of Curiosity’s science in an hour.

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

#48

Post by WalterBright »

rented_mule wrote: post #3

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.

Now that JPL has a design, they could crank out dozens of Curiosities and do lots of science with little more money.

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

#49

Post by somenameforme »

rented_mule wrote: post #3

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.

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.

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

#50

Post by WalterBright »

ozim wrote: post #30
tkcashman wrote: post #13

Earlier quoted context omitted.

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).

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 b…

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.
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