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Antique Fridge Could Keep Venus Rover Cool
Hugh Pickens writes "In the 1970s and 80s, several probes landed on Venus and returned data from the surface but they all expired less than 2 hours after landing because of Venus' tremendous heat. It's hard to keep a rover functioning when temperatures of 450 C are hot enough to melt lead but NASA researchers have designed a refrigeration system that might be able to keep a robotic rover going for as long as 50 Earth days using a reverse Stirling engine. NASA has not committed to a Venus rover mission, but a 2003 National Academies of Science study recommended that high priority be given to a robot mission to investigate the Venusian surface helping to answer such questions as why Venus ended up so different from Earth and if the changes have taken place relatively recently."
I've got an easier solution. Don't make the robot out of lead.
venus is a better terraforming candidate than mars. oh sure, if you want to get somewhere as quickly as possible that is vaguely hospitable to settlement, mars beats venus hands down
but if you want to talk about recreating earthlike conditions (water, temperature, gravity, atmospheric density), i think it would easier (easier, not easy) to precipitate out venus' atmosphere than to bulk up mars'. and if you stood on venus right now, you would weigh roughly the same. big bonus right there
where is all the water going to come from? how the heck do you thin out the venusian atmosphere to earth-like densities? i don't know. but however you do it, it's an easier starting scenario than mars
intellectual property law is philosophically incoherent. it is your moral duty to ignore it or sabotage it
While stirling engines are certainly old, the idea of using them as refrigerators is just recently catching on. Here in sleep Athens, OH a company called Global Cooling is the forefront producer of such devices (and is still hand-making a good number of them).
The nice little advantage to these coolers is that they operate with very high COP's, and are limited in lower temperature merely by available power and the boiling point of the working gas. In global cooling's case, Helium is typically used, so temperatures down to around 5K are obtainable (at which point the helium liquifies. Yeah. Cold.) Also, control of the device can be very precise, in that instead of a compressor kicking on and off, it operates constantly, quietly, and with good variable control.
LG is beginning to outfit refrigerators with Stirling pumps because they're so much better than current designs - only problem is they're not mass produced yet. Coleman has a portable unit shown here that is quite a nice unit, albeit very pricey.
One of my professors here at school is one of the pioneers of Stirling refrigeration, so I've been exposed to it a lot. If the whole country switched their refrigerators to stirling compressors, California could shut off its power grid and we'd still have a surplus of energy country-wide.
Quiz: True or False -- On a scale of 1 to 10, what is your middle name?
Sterling's are older than the 70's. I've been tinkering on using a sterling for cooling off an engine block for a few years now (pretty good results too, allowing me to generate electricity from the previously wasted heat).
Karma Whoring for Fun and Profit.
Yeah, an engine, sure: http://en.wikipedia.org/wiki/Image:BetaStirlingTG4web.jpg
Yes, but can this device provide adequate cooling for a pair of NVIDIA 8800's in a brutal "room temperature" environment?
Unfortunately, the rotation of Venus is ridiculously slow, that would create a problem, not only for human work cycles but, much worse, for managing temperature.
Suppose they create some kind of shield between Venus and the sun, for instance with a swarm of thin foil satellites. The surface temperature would fall down to bearable levels, perhaps to the point of solidifying the CO2, which would make the atmospheric pressure fall. But even assuming that kind of technology, I see no way to get Venus rotating close to the Earth and Mars rates of about 24 hours.
I would rather put a Stirling-cooled robot rover on Venus than pairs of human feet in the dust of the Moon.
Robotic exploration of our solar system is critically important and will achieve much more than a pair of glass-encased Lunar baby blues.
Leo Szilard was later instrumental in launching the US' Manhattan Project to build the atomic bomb. It was his idea, but he got Einstein to write the letter to President Roosevelt that convinced him to fund the project.
Request your free CD of my piano music.
Water lowers the viscosity of magma.
http://www.geoffreylandis.com
We at Venus welcome your cool beer-carrying roverlords. We're damned thirsty over here.
Table-ized A.I.
It's hot and nothing is melted. On earth the melting point of rock is lowered by the amount of water they contain. Water acts as a flux. On Venus where the climate is intensely hot and dry, crustal rocks melt at a very high temperature and are very strong. They create some pretty wild landforms (scarps, cliffs...) as a result.
This or this don't seem so boring to me. The Maxwell Montes are higher than the Himalayas. With adiababic cooling their tops will be hundreds of degrees cooler than the planetary mean. Also, with all of the volcanism and mobile lava flows you can expect there to be some amazing lava rivers and lava tube caves.
an ill wind that blows no good
All the example of the Roman general proves is that it's not a good idea to make predictions, especially about the future. Sure, the Roman general would probably have laughed at you if you told him about a time, two thousand years in the future, where people would travel in horseless carriages, fly through the sky, send words, voices, and moving pictures across the world, and worship a crucified Jew.
On the other hand: where IS my flying car? 50 years ago I'm sure you could find people confidently predicting that in the far-off future of 2007, people would have androids do their chores, live under the sea, and fly to work in that flying car. And of course, it'd all be run on nuclear power. You can't tell me that "lack of imagination" is the reason I don't have my flying car. Flying cars, it turns out, are pretty damn hard to build.
About all we can do is extrapolate from current trends. Ten years from now, I'll be able to buy a faster PC with more memory and hard drive space, my cell phone will be smaller, more organisms will be genetically engineered, and Michael Jackson will be even more freaky. But will AIDS be cured? If I lose my daughter in a terrible accident, can I clone her? Will we solve global warming? Will Duke Nukem Forever be released? The revolutions are hard to predict. Our ignorance makes many possible things seem impossible, and many impossible things, seem possible. Where does terraforming Venus fit in? Hard to say. My gut feeling is that if it ever happens, it will come long after the day we all have flying cars. Of course, I may be forced to eat those words. But if that time ever comes, I will do so gladly- I'll be having too much fun with my flying car to care.
If one assumes that Venus is the sister planet to Earth, formed out of swirling stellar material billions of years ago along with the Earth, then Venus should be about 20 degrees warmer at any given latitude than Earth is. And, in fact, that is what was taught 50 years ago before we had sent any probes to peer beneath Venus' dense cloud cover. When the 900 degree F surface temperatures of Venus were discovered in 1970 by the USSR's Venera 7 probe, Carl Sagan devised his "super greenhouse" theory, which instantly became the standard theory for explaining the extreme surface temperatures on Venus. Sagan's claim was that the less than 2% of solar energy which somehow finds its way through the thick carbon dioxide clouds of Venus to the surface is forever trapped there and cannot re-radiate as infra-red flux, and thus escape (flux is a measurement of an amount of something that flows through a unit area per unit time).
The only competing theory at the time was posited by Immanuel Velikovsky, who pointed to evidence supporting the notion that the planet Venus was a new planet that was still in the process of cooling down. Although Velikovsky's "Worlds in Collision" was so popular with the public that it once held the title of bestseller, the mainstream astrophysical community scoffed at the notion that an outsider whose expertise was in linguistics could offer any value whatsoever to a discussion about Venus' hot temperatures.
Carl Sagan's theory would require that Venus' atmosphere be in something called thermal balance. In other words, in order to rule out the possibility that Venus' heat originates from the planet itself, scientists must establish that the heat absorbed by Venus from the Sun must equal the heat emitted by Venus back into space. If Venus' surface was emitting more infrared light than the sunlight it was receiving, then Sagan's greenhouse theory would be ruled out and scientists would have to consider the possibility that Venus was probably cooling down from some past catastrophic event --a finding that could lend credence to Velikovsky's assertion that Venus was a new planet.
The November 13, 1980, issue of New Scientist contained an article titled, "The mystery of Venus' internal heat". It reads as follows:
"A man cannot begin to learn that which he thinks he already knows." --Epictetus, 1st Century A.D.
Your comment is classical pseudoscience tactic: find some problem with actual theories and claim "so my completely ludicrous idiotic shambling on acid must be right!!!!oneone".
And for rest of universe, I would like to present Velikovsky in all ot his (in)famous glory...
http://en.wikipedia.org/wiki/Immanuel_Velikovsky
http://skepdic.com/velikov.html
"report the arrival of Venus into our solar system as a comet-like body within the past 10,000 years"
No. Venus was to be expelled from Jupiter. And remind me, what comets have anything in common with Venus? Mass? Temperature? Looks? Materials? Orbital parameters?
What modern Obelix would say today? Of course, "Those crazy Americans!".
Or (c): the apparent brightness of the Sun is measured from Earth, the apparent brightness of Venus is measured from Earth, and a simple inverse square law calculation is done.
Real Daleks don't climb stairs - they level the building.
Wouldn't that be veneraformed or something?
Also, you forgot: 7. ??? and 8. Profit!
-Mike
I'm sorry; I don't know what I was thinking!