And you can issue commands using a half shell
February 8, 2017 9:32 AM   Subscribe

"We finally have a computer that can survive the surface of Venus... one of the most inhospitable places in the solar system. Descending through the clouds of boiling sulphuric rain is actually the easy bit—the hard bit is not being cremated by the surface temperature of 470°C (878°F) or crushed by the atmospheric pressure, which is about 90 times that of Earth, the same as swimming 900 metres under water.

"One of the core problems of exploring Venus is that normal digital computers don't really work there. Standard silicon chips can hang in to around 250°C, but eventually there's just so much energy in the system that the silicon stops being a semiconductor—electrons can freely jump the bandgap—and everything stops working. The Venera landers kept their electronics cool with cumbersome hermetically sealed chambers, and sometimes the innards were also pre-cooled to around -10°C before being dropped into the atmosphere by the parent orbiter."

On a related note, 1414°C is the melting point of silicon itself.
posted by Celsius1414 (32 comments total) 36 users marked this as a favorite

 
Eponys... oh I see you already covered that
posted by clawsoon at 9:33 AM on February 8 [28 favorites]


Yesyesyesyesyes
posted by showbiz_liz at 9:48 AM on February 8


It's annoying that there's no credit for, or explanation of, the two photographs at the top of the article. Besides the fact that they don't even mention the original source of the images, the coloration, perspective rendering, and other image processing are nontrivial work - due to Don Mitchell, I think (see the Venera 13 section).
posted by Wolfdog at 10:05 AM on February 8 [10 favorites]


Eponys... oh I see you already covered that

Preponysterical!
posted by ChurchHatesTucker at 10:07 AM on February 8 [12 favorites]


Ray Bradbury's Fahrenheit 2,577.2 - the temperature at which silicon melts...
posted by qcubed at 10:10 AM on February 8 [5 favorites]


This is super cool! I hope human civilisation lasts long enough to send a new lander to Venus equipped with new computers built on this pattern.
posted by tobascodagama at 10:11 AM on February 8


A significant portion of my career has been devoted to environmental testing of electronics and other goodies. We have a hard enough time getting stuff to work in "worldwide climactic conditions", so the fact that things can operate in space or on other planets is truly remarkable.

I've seen equipment fail for any number of reasons - temperature shocks crack solder joints, sand and dust bind rotary joints, humidity and salt corrode just about everything. And this is all in conditions that you would expect to see on Earth! I've never even seen test equipment that could subject specimens to the temperature and pressure you're looking at for Venus.
posted by backseatpilot at 10:17 AM on February 8 [7 favorites]


Faved for title (see related)
posted by kurumi at 10:29 AM on February 8 [4 favorites]


The big push for SiC semiconductors right now is in power electronics (power supplies, motor drives, etc). The advantages are higher performance at high voltages (1000+ V) and easier cooling. SiC has more than double the thermal conductivity of silicon. It's close to pure copper. Also, since it can run at higher junction temps, you can run components that much hotter, which improves heat conduction to the environment.

GaN also has a some of these advantages, but I think there's only one company selling GaN mosfets right now, whereas SiC is sold by several.

Most of these exotic semiconductor materials were pioneered by LED companies (different bandgaps = different colors). Also RF chipmakers, for high frequency microwave stuff. It's really exciting seeing them moving into power electronics. A lot of it is being driven by the huge demand for compact, very high power motor drives (thanks, electric cars).
posted by ryanrs at 10:37 AM on February 8 [6 favorites]


Preponysterical

Meponysterical!
posted by Celsius1414 at 10:40 AM on February 8 [8 favorites]


The first human on Venus will also be the first meal cooked on Venus.
posted by tommasz at 11:11 AM on February 8 [4 favorites]


"We finally have a computer that can survive the surface of Venus...

Sweet, I'll be able to stay on Facebook as I'm literally cooked alive! THIS IS PROGRESS PEOPLE!
posted by Brandon Blatcher at 11:13 AM on February 8 [2 favorites]


My favourite thing about the Venus landers are their gem windows. You can use sapphire, unless you're using an IR camera, which requires you spring for diamonds. I'm sure I've read something about the adventures the USSR had sourcing gems for Venera, but nothing's turning up on the web.

Pioneer Venus:
The instrument principal investigator as well as the probe window specialists finally concluded that natural diamond was the only possible window material. The next challenge was the procurement of an uncut stone that would yield the proper size window. After an intense search conducted by New York's diamond merchants, two stones, weighing 31 and 200 carats respectively, were purchased to yield the prime and backup windows.
Amusingly, sending stuff into space counts as an export, which means they got the customs duty on the cut window refunded.
The precedent-setting agreement classifies a spacecraft as an export. Once launched, satellite components were judged to be “severed from the possibility of trade within the United States” and therefore considered to be exports, according to Customs officials.

Since the U. S. Customs Service considers the Pioneer Venus mission spacecraft to be exports, the $12,474 duty paid on a 13.5 carat diamond window manufactured by D. Drukker and Sons in Holland was refunded to Hughes, which then credited the amount to NASA’s Pioneer Venus account.
posted by zamboni at 11:27 AM on February 8 [61 favorites]


AI can go colonize Venus.
posted by Burhanistan at 11:31 AM on February 8 [1 favorite]


What about floating above it all in a balloon?
posted by My Dad at 11:31 AM on February 8 [1 favorite]


Ctrl+F overclock
Phrase not found

:(
posted by The Tensor at 11:50 AM on February 8 [2 favorites]


Somebody tell Honda's F1 engine team, I hear they've been looking for some electronics that don't overheat.
posted by sfenders at 11:51 AM on February 8 [2 favorites]


Venus is unbelievably co-- uh, fascinating!

Check out this hemisphere-spanning bow wave recently recorded by the Japanese Akatsuki probe.
posted by jamjam at 12:11 PM on February 8 [1 favorite]


posted by Celsius1414

eponyseewhatyoudidthere
posted by disconnect at 12:18 PM on February 8


I'm sure I've read something about the adventures the USSR had sourcing gems for Venera, but nothing's turning up on the web.

Actually, I may be getting confused with NASA's adventures going gem shopping in NYC. The USSR was still shoveling diamonds out of Mir at that point.
posted by zamboni at 12:34 PM on February 8 [1 favorite]


eponyseewhatyoudidthere
eponysee°Cwhatyoudidthere
posted by zamboni at 12:35 PM on February 8 [5 favorites]


This 2009 paper on novel Venus surface technologies (PDF) mentions not only high-temperature semiconductors but also (p23) the possible use of good old-fashioned thermionic valves. As it notes, their internal operating temperature is already hotter than Venus's surface...
posted by Major Clanger at 1:47 PM on February 8 [2 favorites]


GaN also has a some of these advantages, but I think there's only one company selling GaN mosfets right now, whereas SiC is sold by several.

SiC can also be made in larger wafer sizes up to 300mm as I recall. III-V wafers are brittle as hell so they can't make very big wafers
posted by Dr. Twist at 2:52 PM on February 8


What about floating above it all in a balloon?

Thank you for volunteering, do keep detailed notes for the next victims!
posted by Brandon Blatcher at 3:16 PM on February 8 [1 favorite]


Go. At. Night.
posted by hal9k at 3:19 PM on February 8 [1 favorite]


Go. At. Night.

I would be amazed if temperatures varied much from day to night on Venus.
posted by Jpfed at 7:29 PM on February 8


I think it's GaN with the wafer size advantage, since the current tech seems to be GaN film over a silicon wafer substrate. GaN can also be deposited on sapphire or SiC, but both of those are much more expensive than plain old silicon.

GaN over Si is apparently durable enough that at least one manufacturer (EPC) only sells passivated dies. No packaging at all, just solder bumps. You can buy 'em on Digikey.

I think wafer sizes for Sic and GaN are in the 100-150mm range right now. And there's plenty of normal silicon mosfets and igbts that aren't on 300mm yet. Power semiconductor manufacturing lags microprocessor/dram/flash fab tech quite a bit.
posted by ryanrs at 7:40 PM on February 8


And you can issue commands using a half shell

Can I program it in Logo? That's some real turtle power.
posted by panama joe at 7:51 PM on February 8 [2 favorites]


Go. At. Night.

In that neighborhood, are you nuts?
posted by Brandon Blatcher at 5:41 AM on February 9 [5 favorites]


more venera pics
posted by judson at 7:37 AM on February 9 [1 favorite]




I would be amazed if temperatures varied much from day to night on Venus.

I looked into this out of curiosity, and indeed: "The surface of Venus is effectively isothermal; it retains a constant temperature not only between day and night sides but between the equator and the poles."
posted by jedicus at 8:51 AM on February 21 [1 favorite]


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