[HN Gopher] JPL's Design for a Clockwork Rover to Explore Venus ...
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JPL's Design for a Clockwork Rover to Explore Venus (2017)
Author : bartman
Score : 120 points
Date : 2021-05-15 11:10 UTC (1 days ago)
(HTM) web link (spectrum.ieee.org)
(TXT) w3m dump (spectrum.ieee.org)
| ArtWomb wrote:
| Great Sunday morning read for the Venus heads out there. I
| especially dug the radar reflector comms designs that can
| transmit wind speed data directly sans processing ;)
|
| NASA exploration budgets are so constrained now, risk is the
| limiting factor. The best way to gather Venus data is probably
| going to be disposable autonomous swarm drones. If they can be
| fabricated cheaply enough, just let them burn up.
|
| Lofted Environmental Venus Sensors (LEAVES)
|
| https://www.nasa.gov/directorates/spacetech/niac/2021_Phase_...
| hashkb wrote:
| So... hire to SpaceX do it?
| wolverine876 wrote:
| > NASA exploration budgets are so constrained now
|
| Why are they so constrained and by whom?
| katmannthree wrote:
| Fascinating article, I wish they could publish some design
| examples. I would love to see some examples of clockwork
| mechanisms operating in a 500deg C oven, a temperature where the
| blackbody radiation coming off the structure will almost* be
| visible to the human eye. Even just finding lubricants that can
| last in that environment without slowly degrading the metals
| they're there to protect is probably a struggle.
|
| *the threshold is 524deg C, it's close but not quite there
| jessriedel wrote:
| Tbc, if the structure is at the same temperature as its
| surroundings (which is the point of these proposals -- no
| refrigeration required), then this radiation cannot be used to
| visually distinguish the structure from its surroundings. The
| reason is that all blackbody radiation is the same, regardless
| of the surface it's coming off of. The inside of every closed
| and equilibrated oven looks identical, regardless of shape and
| contents: a uniform glow in all directions.
|
| In other words, if there was a human down on the surface who
| could somehow survive and look around from a nuclear-powered
| refrigerated spacesuit, they would only be able to distinguish
| the robot structure by the radiation it was reflecting/emitting
| _other_ than the blackbody radiation associated with the
| ambient temperature.
| jvanderbot wrote:
| The funding agency with announcement is here
| https://www.nasa.gov/directorates/spacetech/niac/2017_Phase_...
|
| I'm sure if you email them, they can direct you to the reports.
| The are usually hosted on the NIAC site, but there was some
| dustup over accessibility concerns, I think.
| Robotbeat wrote:
| At 500C, you can see a full red.
| wearywanderer wrote:
| Might graphite do the trick? Or maybe boron nitride.
| Sniffnoy wrote:
| Note that this article is from 2017, and that since then, this
| approach, and the more obvious approach of just using electronics
| that can withstand such high temperatures, seem to have merged:
| https://www.sciencemag.org/news/2017/11/armed-tough-computer...
| Robotbeat wrote:
| I wrote a paper as an space research intern about how to do
| high temperature electronics for a Venus probe and the paper
| was published before this 2017 clockwork rover idea (& I
| wouldn't argue that our paper was massively groundbreaking,
| just sort of a new synthesis of existing ideas... our mentor
| already knew this was feasible):
|
| https://ntrs.nasa.gov/api/citations/20150002090/downloads/20...
|
| https://www.researchgate.net/publication/272522839_Venus_hig...
|
| I like the unique constraints of trying to make the computation
| mechanical, but... It was IMO clear well before 2017 that the
| electronics option was more feasible than the mechanical
| approach. Glenn Research Center has had high temperature
| electronics for quite a while.
|
| EDIT:And now we have full up high temperature SiC integrated
| circuits and memories. Totally obsoletes the hand wavy SiC
| circuits in my intern paper, but it is truly an amazing
| capability compared to anything mechanical:
| https://hackaday.com/2021/05/03/silicon-carbide-chips-can-go...
| Animats wrote:
| Progress continues. Silicon carbide electronics is coming
| along nicely outside of NASA. There's now a small system on a
| chip, from a company in Arkansas, rated for 500degC.[1]
| There's interest in high-temperature ICs for sensors inside
| jet engines and down-hole sensors for oil drilling. Silicon
| carbide power transistors that can run very hot without
| damage are commercial products.
|
| I wonder how you assemble circuits of components that run
| above solder-melting temperatures. Laser welding, probably.
|
| [1] https://www.ozarkic.com/products/
| 7thaccount wrote:
| I've worked with plenty of engineers from UA and have heard
| the name Mantooth in passing. What a small world.
| Robotbeat wrote:
| Indeed, and they got the technology transferred to them
| from NASA Glenn:
| https://technology.grc.nasa.gov/featurestory/ozark-award
|
| This is a great success story so far.
| dcminter wrote:
| Am I naive to imagine that exotic-materials based
| microelectronics, or even vacuum tube technologies might be more
| realistic?
| hashkb wrote:
| The article mentioned the issue with vacuum tubes: they work,
| but are at high risk of losing vacuum.
| dcminter wrote:
| Well, my cheeks are red. I somehow failed to realise that the
| article continued after the embedded video!
| pupdogg wrote:
| The fact that Soviet Venera 13 landed on Venus approx. 40 years
| ago is mind blowing!
| alanbernstein wrote:
| For the obstacle avoidance mechanism, which they say
| realistically can only have one "subroutine", I was thinking it
| would benefit from a random perturbation to the turning angle, to
| avoid getting stuck in a loop. But I wonder how you might
| implement a pseudorandom or chaotic movement in clockwork?
|
| Maybe by summing via multiple weirdly-shaped cams? Or somehow
| extracting information from the motion of a double-pendulum
| system?
|
| Impractical, perhaps, but I can't help wondering the best way to
| do such a thing.
| spiritplumber wrote:
| https://www.reddit.com/r/crappyoffbrands/comments/dzs7ho/swe...
| Something like this then
| LadyCailin wrote:
| If you could somehow manage to track and maintain the movement
| of a triple pendulum, you can have basically true random input.
| https://www.youtube.com/watch?v=dDU2JsgLpm4
| spiritplumber wrote:
| https://www.reddit.com/r/mildlyinfuriating/comments/dzrgnk/r...
| This one works surprisingly well. I got one at a garage sale
| for $10 for a lark, and its fully mechanical "navigation"
| system is surprisingly reliable, in that it rarely ever gets
| stuck.
| nradov wrote:
| The atmospheric wind is a pretty good source of randomness so
| attach a small windmill or windvane to the mechanism.
| NamTaf wrote:
| This reminds me of a 1950s training video from the US Navy that I
| once watched that explained the function of the mechanical
| computers used for fire control of the ship's guns. I found it to
| be a really handy primer on how mechanical computers function and
| may well be of interest if this concept appeals to you.
|
| https://www.youtube.com/watch?v=s1i-dnAH9Y4
| ezconnect wrote:
| That IMP Globus is amazing.
| jvanderbot wrote:
| This is another of the NIAC program's awardees. A fun fact about
| this work is that they crowdsourced a competition to design a
| fully-mechanical obstacle sensor + avoidance steerage. [1]
|
| I strongly recommend anyone who likes reading about crazy ideas
| that just might work to check out the NIAC awardees [2]
|
| 1. https://www.jpl.nasa.gov/news/nasas-venus-rover-challenge-
| wi...
|
| 2.
| https://www.nasa.gov/directorates/spacetech/niac/NIAC_funded...
|
| Disclaimer, my idea was funded this year so I'm on the list. :)
| jk7tarYZAQNpTQa wrote:
| Since cosmic rays are an enemy of electronic equipment, I wonder
| how well would a fluidics [1] system work, and where are the
| limits of miniaturization.
|
| [1] https://en.wikipedia.org/wiki/Fluidics
| grae_QED wrote:
| I'm not sure what fluid you'd be able to use on Venus' surface
| considering it's well over 400degC. Even mercury boils at
| 357degC.
| tokai wrote:
| Molten salts
| a1369209993 wrote:
| Molten lead, maybe? It doesn't need to be a liquid on Earth.
| ccleve wrote:
| Maybe use a gas?
| nealabq wrote:
| The CO2 on the Venusian surface is a supercritical fluid.
| Not sure if that's any help - it's still compressible and
| so still acts like a gas more than a liquid.
| NegativeLatency wrote:
| Is that boiling point at 1 atmosphere?
| JohnJamesRambo wrote:
| Maybe I didn't read far enough but how does it communicate with
| us?
| mfashby wrote:
| Reflectors!
| JohnJamesRambo wrote:
| But don't those need electronics haha?
| foreigner wrote:
| What are they going to use for power?
| NegativeLatency wrote:
| Looks like the robot has a windmill mounted on top, there's a
| video about 1/3 of the way down the page.
| berkeleynerd wrote:
| Nasa's JFET tech is being developed by Ozark IC to create a
| Silicon Carbide RISC-V chip for just this purpose.
|
| https://www.ozarkic.com/2020/05/26/ozark-ic-to-continue-ultr...
| lmilcin wrote:
| I wonder if you could put a small RTG to produce electricity to
| use for thermoelectric cooling. The RTG would have to run pretty
| hot but it would be also rather simple to create.
|
| You need to be able to use temperature differential to produce
| rotation -- that could be taken care of by simple Stirling
| engine. Fortunately, given how thick the atmosphere is, the
| engine would be very small.
|
| Another problem is bearings which would be essential to get and
| keep it running constantly. But here the thick atmosphere also
| helps. The thick atmosphere would make it easy to create
| efficient aerodynamic bearing.
|
| The last problem is magnets. To produce electricity you need a
| magnet. Now, looking at a chart I see that there is a bunch of
| materials with curie temperature higher than temperature on the
| surface of Venus.
|
| Now... just because we can get electronics to run somewhere deep
| below multiple layers of insulation doesn't yet mean we can do
| anything useful. For that you need sensors and I don't know what
| kind of sensors you can build that can withstand that kind of
| temperature.
| CoolGuySteve wrote:
| I was also wondering why not use a heat pump into the thick
| atmosphere. Turns out there is a NASA design for that:
| https://www.newscientist.com/article/dn12905-antique-fridge-...
| socialdemocrat wrote:
| I am not an engineer but I would be curious to know why the
| proposed Venus Rover I write about here would not be better.
| https://link.medium.com/6JDHu2Bajgb
|
| Fluidics based computations should give much better performance,
| miniaturization and reliability.
| restalis wrote:
| What I can tell as an engineer, is that the main issue boils
| down to the level of maturity for the technologies you mention
| in your writing. It's not enough to have publications
| demonstrating feasibility, as from labs to field applications
| it's a long way, where non-trivial work has to be invested in
| things to make them useful enough for any practical purpose.
| The weak chain-link is electronics tech, which has been
| developed to cover energy handling, sensor data acquisition,
| information processing, and electromagnetic field based
| communication, to name a few. Things change, and as Robotbeat's
| comment here1 says, we may rely on silicon carbide based chips
| now, for information processing at least. You mention using
| sound for echolocation and communication on short range scale,
| but the main communication issue is on long scale. You mention
| wind power but, due to its mechanical nature, there is wear and
| tear involved that has to be also addressed as part of an
| engineering solution to confer it any practical value, and not
| much thought has been allotted to those kind of conditions. To
| sum it up, in regard to Venus ground activity, the technical
| means we still have at our disposal are currently still
| mediocre, unfortunately.
|
| 1 https://news.ycombinator.com/item?id=27175751
| socialdemocrat wrote:
| Fluidics has been used for years in industry however. Both in
| automation and for vector control on Jet engines and other
| areas with high temperatures. It isn't just speculation on
| paper and on a lab.
|
| Wind technology is a mature technology however. I cannot see
| why other means of energy generation on Venus would have a
| head start.
|
| All solutions will need to be adapted to the conditions on
| Venus.
|
| As for communication range. You just need to reach something
| like an airship or balloons higher up. At higher altitudes
| you temperature and pressure is no longer an issue and you
| can use whatever technology works on Earth.
|
| To clarify, I never meant to suggest that we could just drop
| a rover on Venus right now. I was simply trying to challenge
| the idea that a mechanical rover was the better idea. I see
| you mention Robotbeat which seems perhaps like a better
| solution. But I still cannot see why a fluidics solution
| would not be better than the mechanical solution proposed
| here. Yes, carbide based chips may be even better.
| [deleted]
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