We Finally Have a Computer That Can Survive the Surface of Venus (arstechnica.com)

Planet Venus is one of the most inhospitable places in the solar system. The surface temperature there is 470C (878F). This has been one of the key challenges that has prevented us from deeply exploring Venus. Normal chips can only function until around 250C, but it appears, we will soon have a computer that can withstand Venus' weather. From a report on ArsTechnica: Now, researchers out of NASA's Glenn Research Centre appear to have cracked the other big problem with high-temperature integrated circuits: they've crafted interconnects -- the tiny wires that connect transistors and other integrated components together -- that can also survive the extreme conditions on Venus. The NASA Glenn researchers combined the new interconnects with some SiC transistors to create a ceramic-packaged chip. The chip was then placed into the GEER -- the Glenn Extreme Environments Rig, a machine that can maintain Venus-like temperature and pressure for hundreds of hours at a time. The chip, a simple 3-stage oscillator, kept functioning at a steady 1.26MHz for 521 hours (21.7) days before the GEER had to be shut down.

Comments

Confused?

[Anonymous Coward]

"We Finally Have a Computer..."
"...we may soon have a computer..."

From the don't-count-your-chickens dept. ?

Re:Confused?

[Rei]

Your post is largely correct, with the caveat that with proper insulation, the rate of heat flow to the exterior can be kept surprisingly small. But RTGs are indeed hindered by the external heat that they have to reject waste heat to. Solar power surprisingly actually works on the surface, but at terrible efficiency (if I recall correctly, something like 2.7W/m). And wind indeed has been proposed as a power source. Windspeeds are low, rarely more than a meter per second or so, but due to the high density it's not actually a bad power source. There's even been one wind-propelled rover proposal under investigation (Zephyr).

Indeed, the whole point of long-term Venus landers is indeed not large amounts of power, but basically surface "weather stations" or "seismic stations" that just sit there using a few watts here and there and transmitting results up to a higher power relay.

On the other hand, getting things to the surface of Venus is surprisingly easy. Landis once worked out that you could launch a hollow titanium sphere to Venus, have it aerocapture, and land safety on the surface, without any sort of aeroshell, ablation system or parachute whatsoever. Venus has a big "fluffy" atmosphere for slowing things down, and by the bottom the density is so great that terminal velocity can be survivable for well-built probes.

Hi, I was a scientist at Buzzfeed

[Overzeetop]

How, as an editor for a tech site, do you hire someone who can't even recognize a total goof in the summary intro? The PRESSURE at the surface of Venus is 90x that of earth.

I'd understand if you had one or two editors posting hundreds of stories a day - one might slip through. But you're barely posting one story an hour to the front page. How do you fuck that up?

Re:900 is 90 times hotter than Earth?

[danbert8]

Except 0 is arbitrary in Farenheit... Average Earth temp is 287 kelvin, average Venus temp is 735 kelvin. So really it's only like 2.5x hotter than Earth by any objective measurement. Otherwise you could say a 1 degree F day is infinitely hotter than a 0 degree F day and mathematically on an arbitrary scale, that would be correct.

Pressure is about 90 times that of Earth

[Geoffrey.landis]

The statement was "the hard bit is not being cremated by the surface temperature of 470C (878F) or crushed by the atmospheric pressure, which is about 90 times that of Earth, the same as swimming 900 metres under water".

It's the atmospheric pressure, not the temperature, that is about 90 times that of Earth

Re:900 is 90 times hotter than Earth?

[AK Marc]

Because nobody uses Rankine, except when pointing out it exists.

And Samsung will supply the batteries

[billrp]

That extreme pressure should keep them from exploding

Re:Is it really that hard?

[Anonymous Coward]

Your refrigerator's heat pump is a phase-change coolant system (i.e. enormous coefficient of performance), working against a small temperature difference (perhaps 20K), with a small heat flux (A few watts of heat seeping in). These performance specs are pretty much trivial to meet, which is why modern fridges are pretty much sealed, lifetime-performance units. The reason why is that the amount of work a heat pump has to do is proportional to the SQUARE of the temperature difference: The amount of heat leaking in, and the amount of work needed to expel a given amount of heat, are both proportional to delta-T. Keeping a well-insulated box 20*c cooler than its surroundings is easy. Really easy.

INITIATE SIMPLE BACK-OF-ENVELOPE ENGINEERING PLAUSIBILITY ANALYSIS

Supposing we want to keep the inside of a Venus probe down to a mere... 100*C? Now we have a 330 degree temperature difference. That's 17x the temperature difference in your coldbox: The venus probe's fridge will have 275 TIMES the work to do per unit area & insulation. Shit.

Suppose the probe is a silvered ball 2 meters in diameter. Let's plug in... 30mW/m-K and give it a 250mm thick aerogel insulator all around its inside surface. That's roughly 500W of heat leaking in from a 430C ambient, and we haven't put ANYTHING through the aerogel (like the supports for the probe's internal goodies...) which will send that through the roof.

The radiator itself is a fairly simple matter - only 800cm^2 of outward facing blackbody surface, heated to 500C, will dump our waste heat into a 430C ambient. I don't know nearly enough about refrigeration technology to say what a mechanical refrigerator capable of pushing 500W of heat up a 400* difference will look like... My first google search brought up a unit capable of dumping 500W in the vicinity of room temp across probably a 20C difference (HRU-1000) which fills .012 cubic meters. Naively scale it to do 270x the work, that's eating 3.2 cubic meters of probe volume in order to keep the inside down to a blazing 100*C. Our 2-meter-diameter probe, with 250mm of aerogel shell, only has 1.7 cubic meters of internal volume.

We're out of space twice over and we have no atomic power supply, no scientific instruments, no computer, no radio to talk back to earth... Also I don't think the world's remaining Pu-238 stockpile can build a themionic generator capable of powering that fridge, but that's a "minor technical detail."

Heat leakage scales as area, volume scales as volume, so the situation gets better for bigger probes. Fat chance of that, seeing as the last Saturn V is sitting on its side in pieces... There's no way a usefully chilled Venus surface probe happens in the realistic near future.