JPL's Design for a Clockwork Rover to Explore Venus (2017) | Hacker News Reader

JPL's Design for a Clockwork Rover to Explore Venus (2017)

spectrum.ieee.org

149 pointsbartman47 comments

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

Fascinating article, I wish they could publish some design examples. I would love to see some examples of clockwork mechanisms operating in a 500° 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 524° C, it's close but not quite there

Might graphite do the trick? Or maybe boron nitride.

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.

The emissivity of different materials is going to differ. For purposes of thermal imaging this will yield some contrast to an image.

At 500C, you can see a full red.

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.

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...

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...

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 500°C.[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/

I've worked with plenty of engineers from UA and have heard the name Mantooth in passing. What a small world.

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.

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_...

So... hire to SpaceX do it?

> NASA exploration budgets are so constrained now

Why are they so constrained and by whom?

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. :)

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.

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

The atmospheric wind is a pretty good source of randomness so attach a small windmill or windvane to the mechanism.

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.

https://www.reddit.com/r/crappyoffbrands/comments/dzs7ho/swe... Something like this then

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.

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-...

Am I naive to imagine that exotic-materials based microelectronics, or even vacuum tube technologies might be more realistic?

The article mentioned the issue with vacuum tubes: they work, but are at high risk of losing vacuum.

Well, my cheeks are red. I somehow failed to realise that the article continued after the embedded video!

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

I'm not sure what fluid you'd be able to use on Venus' surface considering it's well over 400°C. Even mercury boils at 357°C.

Maybe use a gas?

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.

Is that boiling point at 1 atmosphere?

Molten salts

Molten lead, maybe? It doesn't need to be a liquid on Earth.

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...

The fact that Soviet Venera 13 landed on Venus approx. 40 years ago is mind blowing!

Looks to be inspired by Theo Jansen's Strandbeest https://www.strandbeest.com/

What are they going to use for power?

Looks like the robot has a windmill mounted on top, there’s a video about 1/3 of the way down the page.

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.

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

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.

"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."

Here on Earth we assume that the areas with extreme conditions can be contained, and normal conditions can be taken for granted for everything else. Yes we have engineering involving high temperatures, we also have easy available heat sinks. That is totally different from Venus, where we'll have to assume that the entire system will quickly reach to the environment's high temperature, that there will be little to no practical means to significantly cool off the equipment, and that that will be the assumed normal functioning parameters in the long run. This is a challenge, because as I said, we have limited technology that does not rely on conditions comparable to those on Earth. Part of the challenge in "all solutions will need to be adapted to the conditions on Venus" is that there was little incentive for this to happen naturally on Earth and thus it now can benefit less from the "free" progress that otherwise happened in society at large. There aren't good off-the shelve solutions to be picked and used. These have to be yet expensively researched and developed.

"Wind technology is a mature technology however. I cannot see why other means of energy generation on Venus would have a head start."

The issue is not how well the technology works (even in Venus' ground conditions), my comment has been about the mechanical nature, i.e. a bit on a lower level. Anything with moving parts will be exposed to a high degree of wear and need for maintenance. From an engineering POV you normally want to either avoid that or compound the problem by designing maintenance.

"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."

Not getting into the technical means of production and reception of the sound in Venus' conditions, nor into the reason for choosing sound as means of communication, this calls for a chain of balloons placed close enough to be able to "hear" each other in order to relay information up to an altitude where normal EM communication can be used. That's something we have yet to develop here on Earth. It would be interesting to know how we'd ensure balloons positioning, considering the unavoidable winds and other interference from atmospheric activity.

Despite the reserved attitude conveyed in what I've written here, I'm actually all for Venus exploration, and I consider it the most important next-target in human evolution, as may be reflected in my previous comments, for example like this one: https://news.ycombinator.com/item?id=24594285

Maybe I didn’t read far enough but how does it communicate with us?

Reflectors!

But don't those need electronics haha?

Mirrors on top, operated mechanically I would guess. The article mentions 'transmitting' windspeed measurements to a satellite this way.

That IMP Globus is amazing.

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