Clockwork rover needed for venus

nasa wants your help !

The russian vega lander was last onsite on venus, which has
90 atmosphere pressure, 470C, and mostly CO2 with sulfuric acid clouds.

Nasa wants to make something that will survive for months - they are looking for sensors for their clockwork (no electronics) rover.

I dont think a heat engine will be useful in this case, since it requires a temperature difference (not just heat) . If we had a cool reservoir we could run electronics, otherwise we need something even hotter than 470C to run the heat engine. There is no shortage of wind at 10-20 km/hr on the surface…

Besides power a big question here is how to run sensors etc that are ‘clockwork’ and dont need electronics . Like some kind of high-temp etching for photography , where you burn light into a metal plate or something. And even that’s not so great since somehow you have to send info back…tbh I don’t see any way to do it other than maybe exploit like a 600C to 470C temp differential from e.g. 100m to 0m off the surface, in order to run a heat pump to cool a chunk of the rover to 100C where electronics can still have a chance…and now you have to keep a 100m high pole from blowing over

I think a floating balloon with oxygen as a lift gas and instrumentation dragging on the surface has a way higher chance of even surviving harsh conditions on Venus. The concept drawing is made to throw people off the real course of action.
Something akin of jellyfish probe will work better. Can make some concept drawings - been playing a lot of KSP lately :stuck_out_tongue_winking_eye:

A sphere of titanium or some metal that withstands sulfuric acid , could float - eg 1m radius and 5mm thickness would have abt 16 liters metal volume or 72kg (for Ti) and volume of 4.2m^3 so thats 17kg/m^3 while the venus atmosphere at ground level is 67kg/m^3, so yeah that titanium sphere would float up (or down if released high) like a party balloon to around 20km according to this chart of venus’ atmosphere density . You could keep electronics and stuff safe from the sulfuric acid inside the sphere, and its also much less hot up there, only around 270C , still too high for normal stuff but maybe there’s SiC things one can use , I dont know if anything is of the shelf today tho.

Incidentally I was wondering why silicon electronics are so sensitive given that Si itself has a very high melting point, I think its due to dopant diffusion at high temps rather than the Si melting. Also I’ve seen thin layers e.g. of gold ‘melt’ at much less than the actual melting point of bulk material.

At this height the lander won’t be able to produce its own power, hence it will be below and deep inside cloud layer. I’ve been thinking about 2 stage lander, where the top part carries power supply, sensitive equipment and cooling systems, and inflates with something like a pressurised air tank. Floats on altitude of 60-70 km (as low as possible to generate power).
Secondary part is something like you described, instrument sphere which carries all the measuring devices, cameras, thermal probes, chemical analysis, and so on. Can be cooled with closed system powered and differentially cooled from the top balloon.

The only challenge is to run and carry 30km of wire and tubing…

Use old technology.
Relays with ceramic insulation.
Ceramic electron tubes like the electron tubes used for power transmitters.
Look for 2c39 rf tube
2nd picture on the right side.

Silicon transistors work upto 200C maximum.
Chips like cpu, microcontrollers to 120C depending on model.

If you have thermionic friends they like heat as the have a cathode filament but too much heat is not good for the anode as it could melt under high load.
But if you have low power ceramic tubes there is a way.
Look for tube “chips” called

Mhh steam punk vintage electronics, good that I played with such stuff as a kid as I found it in the garbage those days:)

If they are really searching for a solution, I could consult them on vintage electronics :slight_smile:

I had a radio with this “integrated” power amp tube.

So have multiple tubes integrated in ceramic steel cans will be a way to do it.

Ludwig we could think of vacuum tube electronics as you suggest if SiC is not there yet - but it seems that SiC devices are becoming available. Amazingly the soviet lander survived for a few hours, long enough to shoot some pictures and send back photos. As for power imho the Nasa idea of wind power is a nice one. So - titanium or other metal sphere with some propellers outside for power generation, using vacuum tube or SiC electronics may be good enough for a powered electronics platform.

How to take pictures? A quartz window can be good for this, I think that’s what Picard (the real physicist who went to 10km depth in the ocean in a titanium sphere, not the fictional startrek bald guy) used, and I guess whatever camera the soviets used before CCDs.

Radio eqpt to send data back to a base station in orbit could use same electronics , vacuum tube or SiC , as long as the atmosphere is not radio opaque I guess this can be a viable system.

The original Nasa rfc is for sensors so I guess the whole discussion above is somewhat off point.
This KTH thesis is on a SiC CCD…and three sentences in, the guy states its for taking pictures on the surface of venus…internet 1, jeremy 0

i was gonna suggest the 2 part approach but max beat me to it

a 2 part unit one above cloud layer and a second one below it both creating lift with “balloons”

both connected with cable running electricity and a heat pipe loop moving heat up to radiators and cooling units and pumping back down cooled coolant

cable weight should not be a problem, metallic balloons along the cable should support own weight

issues i see are
1 insane bulk size (and weight)

2 deployment -this is not an origami shaped heat shield… its tens of thousands of meters of cable that needs to be lowered carefully while being pulled by atmospheric winds\waves

3 wind speed and “viscosity” (cables not strong enough will be snapped, not rigid enough and it wont protect the heat pipe inside/alongside it

another approach could be a “hoping” vehicle / submarine

vehicle parks above clouds - charges electric and cryogenic accumulators/batteries
vehicle compresses /deflate ballasts - dives down to sensors depth ( or lands to run on wheels) to do science
vehicle inflates back the ballasts to go back up to charge batteries/accumulators and relay acquired data

second idea should be easier to implement

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I had the exact same idea about a hopping vehicle, but you beat me to it…

Let me one up you on the 2 part idea: how about 100 parts?

Make 100 small modules, packed full of sensors, and drop them from the balloon. Each one may only provide a small amount of data, say 10 minutes worth of data on average, but combined you can have 1000 minutes worth of data, and from different locations: polar, equatorial, land, lake, hills etc.
You can use regular electronics, improved with some shielding and cooling, since each module is disposable.
With modern electronics, you can pack a lot into each module, the electronics in each module can be no bigger than a smartphone really.

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you will still need a main ship to float above the clouds and relay data but after 100 probes you are done on the direct probing

a diving unit (or a two part unit) could both give data for years and do much more sophisticated probing

Yes, but it could also get destroyed, and then you loose everything. My suggestion is basically to not put all your eggs in one basket.

A main balloon dropping disposable probes… Hmm, it starts to take form.
I suggest you research other Venus probes too, especially the last one -

the challenge is for a rover

they want a rover that can move on the terrain acquire data and relay it out somehow to earth

if we could design a vehicle that could “dive” to do the work acquire data and surface back up to “breathe” and relay data then we might have a chance in the NASA challenge

Venus is an extreme world. With a surface temperature in excess of 840 degrees Fahrenheit and a surface pressure 92 times that of Earth, Venus can turn lead into a puddle and crush a nuclear-powered submarine with ease. While many missions have visited our sister planet, only about a dozen have made contact with the surface of Venus before succumbing to the oppressive heat and pressure after just about more than an hour. Powered by wind, AREE is intended to spend months, not minutes, exploring the Venus landscape.
MONTHS! With a rover on the surface of most extreme and hostile environments in Solar System!
15,000$ is a joke for a project of such a scale.

To be more precise:

“The “Exploring Hell: Avoiding Obstacles on a Clockwork Rover” challenge is seeking the public’s designs for a sensor that could be incorporated into the design concept. The winning sensor could be the primary mechanism by which the rover detects and navigates around obstructions.”

So, really, the issue is designing a sensor.

I’m thinking about something like a broom, attached to the front and/or back+sides of the rover the hairs would be some pins attached to springs. The rover could than rotate, looking for the spot where the overall tension on the springs is lowest, thus indicating clearest path from rubble. It also needs be able to differentiate between solid land and liquid, which can be done by some dipping mechanism, again, attached to springs, to figure out if the surface ahead can support the weight of the rover.

The thinking behind this is to design something like how a blind person navigates with a stick.

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yeah i was thinking hairs too, but simple electronics will still work too , just not silicon so no cpu - so possibly a piezo rangefinder can work , piezo will apparently last at high temp.
A phase sensitive circuit using a few vacuum tubes or again the SiC could possibly do it. (checkit out - off the shelf SiC arrays!)
I was trying to dream up an entirely analog system where some element physically moves according to relative phase of returning sound but cant quite get it

Yes, I have an idea about that. The hairs can be attached to wheels along a shaft, with the shaft being not centered about the wheels. This will create an outline of the terrain sensed by the hairs. The outline can then be swept by a needle, similar to how a record player works (See attached sketch).

This is about as analog as it gets…

It turns out my brother-in-law is the cree-wolfspeed distributor, they produce SiC diodes and transistors. So I ordered samples of those , we can try turning up the heat till the plastic case melts and see if it holds together when there’s no plastic left, e.g. if the metal case is screwed down onto some heat-resistant substrate.
How do you connect components? I guess the ‘punschveiss’ will serve to connect copper wires to metal legs - btw what are transistor/diode legs made of?