Sorry to keep shining rays of optimism here, but circling back to Raytheon's claims, it looks like its more than pie-in-the sky. Here is a 2012 paper describing testing they did with a SiC CMOS at 400C:
http://www.raytheon.co.uk/rtnwcm/groups/rs...emp_article.pdf.

So components that could theoretically function at ambient temperature on the (high plateau/peak) surface of Venus are in labs now. Assuming they're reliable, its just a question of time before they're commercially available.

Finally - if you want something to add to your reading list, I stumbled upon this fantastic overview of the 2013 state-of-the art in high temperature SiCs

dtolman:
Ah, behold the motivating power of proving someone wrong on the Internet!

Thank you. The Raytheon paper is quite useful to me. http://www.raytheon.co.uk/rtnwcm/groups/rs...emp_article.pdf.

(Still, power consumption at temperature is pretty high...)

I'd suspect that the solution will come from the emerging technology of non-silicon transistors with nanoscale materials.

Beyond Silicon: Transistors Without Semiconductors
http://www.sciencedaily.com/releases/2013/...30621121015.htm

--Bill

The Raytheon paper makes no mention to how long it can last at 400C. I've heard that the insulating layer doesn't last terribly long at those temperatures. The fact that no mention is made of length of time is a bad sign.

Thanx Robotbeat for mentioning the power consumption, it brings up another concern.

A hypothetical device on Venus operating at the high ambient temperature there will not be 100% efficient (nothing is anywhere), and it will warm above ambient temperature and need to dissipate some power into the environment.

It's another challenge, the device will need a heat sink (or active cooling, erf) and it makes the situation more complex, like it's not difficult enough already.

The material of the heatsink will need to be compatible with the environment and function properly.

The material of every spacecraft needs to be compatible with the environment it's sent to and to function properly.

If the chamber where it is stored electrical instruments has a static insulation and the air is emptied, the internal temperature would be lower than outside? I think the heat sink in Venus is not useful because the atmosphere is warmer outside than the inside of chamber.

If you can get electronics running at ambient, just leave them exposed* and cool them off with a fan. After all - thats what we do with PCs here when they run hotter than the atmospheric temp

On a more realistic note, if memory serves, the latest surface proposals were nuclear powered and cooled with a Stirling Cycle heat engine. Of course those missions anticipated a 200 C interior and 500 C exterior - a 300 C differential. I imagine the power requirements for running the heat engines would be lower if you can get the electronics closer to 400 C and a 100 C - or smaller - differential, and more than make up for the hotter electronics.

*Now we just need high temperature, acid rain resistant electronics

Not much of acid rain on the surface (sulfuric acid evaporates before reaching ground), but high preesure-hot CO2 is highly corrosive and problematic. It seems that the only thing "easy" for a venus lander is the actual EDL. Parachutes to around 20-30 km, then free fall all the way down.

Indeed, those actively cooled mission proposals are what my mentor has been working on. But the power requirements are pretty big for active cooling, since your heat dump is so hot. That means completely custom high-power radioisotope... Flagship class funding requirement, but at best a Discovery-class risk level, so unlikely to fly before I retire.

But one good thing about Venus's atmosphere is that because it's so dense, it should carry /extra/ heat away rather well, better than on Earth. Of course, the problem is that you have to start out at ~450C or so....

Also, although there is no acid rain droplets on the surface, you do have the products of dissociated sulfuric acid, so corrosion is still a problem. But a better problem to have than the incredibly high temperatures.

Thinking about it, perhaps if the goal is electronics that work in near-ambient temperatures, then the cooling schemes where they need to refrigerate the electronics is all wrong. If the goal is to get to 400+C rated electronics, than a totally different cooling system will be needed. Once you get to the point where the electronics are hotter than the outside air, which at 400 C rated electronics might be true for highland landings, you can switch to less exotic methods - passive radiators, or some kind of liquid cooling (sodium?).

I don't know much about more passive cooling techniques, but I imagine that a sodium (or some other high temperature liquid) cooled electronics bay would be a lot cheaper, lighter, and require less power than a Stirling Engine.

If you can get the electronics to work at just above ambient /reliably for a long time/, then cooling isn't much of a problem in Venus's dense atmosphere. But that's a pretty big if. And the Raytheon stuff isn't "rated" for 400C, it's been operated there for some (presumably quite limited) finite period of time. A problem with the highlands, though, is that it's not really a good place to land something like a seismometer because it looks much rockier than most of the Venera landing sites.

Sorry for the very late notice (RFI responses are due tomorrow); it took a couple weeks to get validated to post here after I registered.

So when can we find out what the result was for the RFI?

---

Of possible interest to those following high temperature electronics news:
A new 230 C rated capacitor has been released AFAIK this is significantly higher than other commercially available capacitors which previously struggled to hit the 200 C mark. I've read a few papers which suggest the ceiling for this kind of technique is around 250-260 C, so still room for improvement.

-
For anyone doubting the commercial pressure/demand for hitting 300+ C, a tidbit from the latest edition of Offshore magazine on the latest Society of Petroleum Engineers conference. Readers here might be amused at the 3rd paragraph of the quoted section (below) - looking to commercial sectors to push high temperature electronics while they look back at NASA to push it forward. Perhaps there are some synergistic opportunities waiting out there?

Just 3 months later a series of new 260 C rated capacitors are now on the market.

--

I had mentioned a DoE high temperature project last year. a 2013 report is out, though it seems to only focus on a new Epoxy formulation tested to 315C.

--

The RFI xCalibrator mentioned was part of NASA's Centennial challenge, but I'll be damned if I can find anything on it at the site.

GE and New York State are moving from 100mm to 150mm wafers for SiC:
http://www.gereports.com/post/91863830615/...uld-make-planes
https://www.governor.ny.gov/press/07152014N...ring-Consortium

One caveat is that the NYS Semiconductor research efforts generate a lot of PR hotair. I'm not even sure GE is the leader in SiC integration. Nonetheless, the fact that the industry's already moving to 6" wafers for SiC does sort of reiterate my earlier point that devices will be VLSI from the get-go with no interregnum period where you have to cobble CPUs together from multiple discrete few-T chips.

Its been a while, but there continues to be a steady drumbeat of every higher temperature commercial components that inch closer to (or even surpass) Venusian temperatures.
Some examples:
GE Announces 250+ C rated Transient Voltage Suppressor (Surge protector)
Roundup of high temperature Elastomers (think, Vulcanized Rubber), rated to 450 C
Ceramic packaging rated up to 1,000 C (!)

This recent conference mentions a talk on a diamond MOSFET (transistor) that worked in temps ranging up to 400 C (10K to 700C in the more detailed notes!).

A recent overview of high temperature electronics note the demand for 200-250 C rated components is growing - with ceramic, Tantalum, and film based capacitors competing in that temperature range.

That's cool. Asking in near-perfect ignorance: what has to happen before component like these can actually be used in deep-space applications? I imagine the process of certifying their reliability is not a quick one.

A full-up system operating in the expected mission environment (temp, pressure, etc.) for at least 3x the desired mission life would be an absolute minimum.

A grant has been made to the university of Arkensas to develop silicon carbide intergrated circuits for temperatures over 300 degrees celcius..

A few items of interest:
Another new 250C tested commercial capacitor (from the graphs, might be able to perform briefly above 250). Also shock tested to 500G. The press release contains a nice guide to the commercial state of the art for downhole high-temp/high-pressure rated electronics. This caught my eye as useful to know:
The UK Energy Institute’s Model Code Of Safe Practice originally standardized a definition for High-Pressure/High-Temperature (HPHT) wells, as having undisturbed bottom-well temperatures above 149°C and needing pressure-control equipment with a rated working pressure of over 69MPa (10,000 psi). These limits are no longer adequate to distinguish today’s most extreme wells, and new definitions are emerging. Although yet to become widely standardised, the ultra High-Pressure/High-Temperature (uHPHT) category now covers temperatures from 204°C to 260°C and pressure from 139MPa to 241MPa, while extremely High-Pressure/High-Temperature (xHPHT) refers to temperatures above 260°C and pressures above 241MPa.

So guess xHPHT is the new google search term to enter in if you're looking for commercial Venusian survivable equipment
Entering it into google shows a small, but growing list, of xHPHT research and products - this one caught my eye:
260 C rated transducer, and a 275 C rated application-specific integrated circuit It reports that the new ASIC has survived over 1,000 hours testing at 275°C. Gotta wonder at what point COTS high-temp equipment doesn't require a nuclear reactor to cool anymore for a viable Venusian lander. More information on their high temperature IC development here

Not specifically high temperature, but
An overview of the current state of Thin Film Resistors - which I mentioned earlier this year as a future technology with high temperature thresholds.

Very interesting stuff, can't wait to see a rover on Earth's sister planet!

new(ish) carbon nanotube ram chips that can withstand 300C for a LONG time
http://hardware.slashdot.org/story/15/06/0...e-nand-and-dram

http://www.computerworld.com/article/29294...ube-memory.html

NASA has awarded a small grant to a University of Arkansas related company to design 500c rated SiC components for a future Venus surface mission.

EDIT: While I'm looking at the subject...
Penn State has developed a new polymer that can remain stable and store energy at temperatures up to 300 C. High Temperature Capacitors is one specific application mentioned in the article.

Pop-sci article on Venus electronics & applications. First I've heard of the concept rover mentioned there.

Wow, an imager running at 600*F? Even if UV only that is one hell of an accomplishment. Hazcams via blacklight!

Meta-news:



http://news.discovery.com/space/hell-on-ea...here-150902.htm

EDIT: see it has already been mentioned - guess it is ready now?

Swedish tech lab KTH is working to develop high-temperature silicon carbide electronics for ambient temperature operation at the surface of Venus.

https://www.kth.se/blogs/wov/
https://www.kth.se/blogs/wov/files/2014/10/..._KAW_160304.pdf

They're pretty ambitious - aiming to demonstrate digital CPUs, amplifiers, gas sensors, seismometers.

From the PDF document linked above:

"
The project started January 2014 and has eight
PhD students in the different work packages.
Our present bipolar technology has been scaled
to smaller transistors, and self‐aligned nickel
contacts have been developed. Four new
integrated circuit designs were made for
different parts of the lander electronics: CMOS
circuit test set, a 4‐bit microprocessor, RF
transistors for the radio transceiver and a
prototype pixel sensor for the imaging. Most of
these have been fabricated by the PhD students
in the KTH Myfab clean room, some are still in
progress. Preliminary testing and modeling
show operation up to 550 °C, sufficient for the
Venus target. A first demonstration has been
made of capacitive inertial sensing at high
temperatures; gas sensors have been annealed
at 500 °C for 300 h; photodiodes sensitive in the
near UV range (200 to 400 nm) have been tested
up to 550 °C. Power sources have been
identified, and passive components like
inductors have been tested to 500 °C.
"

Interesting article I found today: a Sterling engine with lithium fuel? http://www.bbc.com/future/story/20160705-t...weve-ever-built

ROSES-16 Amendment 25 releases the new program element C.24 The Hot Operating Temperature Technology Program.

The Hot Operating Temperature Technology (HOTTech) program supports the advanced development of technologies for the robotic exploration of high-temperature environments, such as the Venus surface, Mercury, or the deep atmosphere of Gas Giants. The goal of the program is to develop and mature technologies that will enable, significantly enhance, or reduce technical risk for in situ missions to high-temperature environments with temperatures approaching 500 degrees Celsius or higher. It is a priority for NASA to invest in technology developments that mitigate the risks of mission concepts proposed in response to upcoming Announcements of Opportunity (AO) and expand the range of science that might be achieved with future missions. Note that this HOTTech program element is not soliciting hardware for a flight opportunity.

HOTTech is limited to high temperature electrical and electronic systems that could be needed for potentially extended in situ missions to such environments. NASA seeks to maximize the benefits of its technology investments and consequently technologies that offer terrestrial benefits, in addition to meeting needs of planetary science. While specific technology readiness levels are not prescribed for the HOTTech program, proposers are reminded that the goal of the program is to mature technologies so they can be proposed as part of a selectable mission concept or technology demonstration to a flight AO with reduced risk. It is the responsibility of the proposer to describe how their proposed technology development effort addresses the goals of enabling or enhancing future mission capability or reducing risk and how the technology will be matured for a flight opportunity as part of an integrated system. Efforts that focus on advancing the technology readiness level (TRL) of a system composed of multiple existing technologies at various TRLs are allowed under this opportunity.

Notices of Intent are requested by September 28, 2016, and the due date for proposals is November 23, 2016.

https://arstechnica.com/science/2017/02/venus-computer-chip/

An oscillator is a very important step in creating a full Silicon Carbide based CPU capable of operating a Venus temperatures. 1 MHz doesn't sound like much, but it is more than enough for basic analysis. The hard thing to get working is an imager - high temps mean leaky pixels. This is yet another great example of NASA dual use, with this tech being very useful for deep well operation.

It may be interesting for those who don't know – cameras used for amateur photography of Deep Sky Objects are cooled internally, reducing the incidence of such noise. A galaxy or nebula may be roughly 1/100,000th as luminous as a planet, and cooling the camera to, say, -15C when outside temperatures are +15C can help tremendously in producing a clear image, whereas this is not needed for imaging planets.

On the surface of Venus, the luminosity isn't a problem, but the temperature is. On the other hand, another solution to this problem would be to provide passive or active cooling for just long enough to take one image, then let the camera die. Potentially, almost all of the science value would be in taking a single image as soon as possible after landing.

So long as the ccd-equivalent sensor doesn't degrade with the heat, active per-image cooling strikes me as feasible. I'd really like to see a rover, rather than just a fixed lander, so multiple images are important. Alternatively, I could envision something like polaroid instant film, a ccd-equivalent on something like a roll, where we get one shot per sensor, read and transmit the image, then roll to the next good sensor.

One problem (aside from heat tolerance) with current sensors is that they have a strong response in the infrared. Not such a good thing on Venus.

Has there been any progress on high-temperature imaging sensors?

If you're using a cooled and sealed environment to house your CCD in, then it is easy enough to deal with the infrared. Just put a filter in the sealed chamber between the camera and the inner window.

Dr Neudeck kindly forwarded me a concept study for a long-duration Venus surface station:

http://www.hou.usra.edu/meetings/lpsc2017/pdf/2986.pdf



SiC imagers have been developed for solar imaging, because they have a high rejection of infrared due to the large band-gap:

http://techport.nasa.gov/externalFactSheet...?objectId=16616
http://techport.nasa.gov/file/15351

Imagine a wind-powered rover using UV cameras to drive across Venus, stopping to recharge using a windmill, and with UV LEDs to keep driving during the Venusian night!

IR cut filters are trivial. The wavelengths silicon sensors are sensitive to are in the very near IR near 1 micron, not in the thermal IR. Imaging in the near IR can be a good thing on Venus because there is less scattering from the atmosphere, at least in some bandpasses. Bottom line: no new technology required if there is some way to cool the sensor.

And we are a long way from having electronics that work at Venus ambient, let alone image sensors, this most recent development notwithstanding.

It sounds like we might be able to contemplate a dumb lander, just sending some basic information like temperature, wind speed, and perhaps seismic data, as early as 5 years from now. Optimistically, maybe a rover with imager in 10-15 years. Technology is coming along. At my age, these time scales aren't too bad

Did anybody notice that the SiC imaging chip in question is solar blind? That means operating in a spectrum area of UV that the sun doesn't put out very much of, let alone worrying whether any of that output could make it through the atmosphere. Which means in turn that you are going to have to have some kind of powerful very short wave UV illuminator to light up the area with.

That's not the way I interpreted the specifications. I think they meant solar-blind in the sense that they don't need special protection against the IR and visible light coming from the Sun: The sensor is inherently not sensitive to IR and visible light, and can tolerate very high operating temperatures.

mcaplinger - The abstract is really for a UV-targeted imager, not necessarily a SiC specific one. They state

"The high sensitivity of silicon CCDs and CMOS arrays in
the visible and near infrared (IR) is a liability when employing
these same arrays in the ultraviolet. As exemplified in the
Hubble telescope instruments, long wavelength blocking filters
exact a high price due to their low transmission in the ultraviolet."

So for their needs a SiC imager is better for UV sun imaging than an Si based imager + IR Cut.

I posted the link to show that SiC based imagers (not necessarily tuned for the Venus environment yet) do exist. They do point out the underlying JFET technology can tolerate 300*C temps.

The Science journal has a new article about the recent advances in high-temperature electronics for Venus missions, especially silicon-carbide chips developed at the Glenn center:

http://science.sciencemag.org/content/358/6366/984

The current record holder has 175 transistors and is already considered for actual missions. The article also mentions a separate work done at JPL using mechatronics (gears and stuff) instead of transistors, which sounds positively like steampunk.

The topic is a bit timely, with Mars Insight launching soon: a low-bandwidth lander with a conventional camera, conventional laser spectrometer, and conventional mass spectrometer plus high-temperature electronics supporting a seismometer could be a heck of a mission. The first three instruments would work for an hour and give us observations upon arrival, while the seismometer would work for months, at least. I suspect that Venus has enough quakes that a few months would be very informative. It'd be really nice to drop two of these at different latitudes of the same longitude and locate the epicenter of the quakes.

In order to investigate possible ongoing volcanism, I'd presume, that one would be interested in longer-lasting atmospheric spectrometry.

Long-term monitoring of atmospheric composition would certainly be interesting and perhaps the instrument and its logic could be done with high temperature electronics. It's an open question as to how long an interval would be likely to detect changes, which has been done from orbit, revealing roughly one spike in SO2 per decade. Perhaps smaller spikes are more frequent.

Over two years old now, a proposed Venus surface mission that would use high-temp electronics for long-term monitoring of seismic activity and atmospheric changes.

The upshot is, something like Viking and Insight for Venus, with a surface mission of 120 days for one or two landers. Note that the slow rotation of Venus constrains the choice of landing sites whether or not the landers accompany an orbiter that could perform data relay.

https://www.lpi.usra.edu/vexag/reports/SAEVe-6-25-2018.pdf

This general topic seems to be...heating up (yeah, sorry ). Recent article describing a high-temp radio that may serve as a core component of future Venus surface missions.

Some recent promising developments in high temperature electronics.

Applied Physics Letters free article on SiC and GaN

SiC is up to 200mm wafers:
https://www.wolfspeed.com/company/about/mohawk-valley-fab/