Posted on 11/13/2007 9:55:10 AM PST by Freeport
A high-tech refrigeration system could keep a rover functioning for weeks on the searingly hot surface of Venus, say NASA researchers. A long-lived Venus rover could help scientists understand why Venus, with its runaway greenhouse effect, has become so different from Earth.
The surface of Venus broils at a temperature of about 450 °C – hot enough to melt lead. Several probes in the Soviet Venera and Vega series, as well as a NASA Pioneer Venus probe, landed on Venus and returned data from the surface in the 1970s and early 1980s. But they all expired in less than 2 hours because of the tremendous heat.
Now, two NASA researchers have designed a refrigeration system that might be able to keep a robotic rover going for as long as 50 Earth days. The work was carried out by Geoffrey Landis and Kenneth Mellott of NASA's Glenn Research Center in Cleveland, Ohio, US.
The main concern is keeping the electronics cool. The NASA pair plan to do this by packing the electronics in a ceramic-based insulator and placing it inside a metal sphere about the size of a grapefruit.
Stirling cooler Heat would then be pumped out of the sphere using a Stirling cooler, which works by compressing and then expanding a gas with a piston. When the gas expands, it cools down, absorbing heat from the electronics chamber. Then, as the gas is compressed and its temperature rises, the heat is allowed to dissipate in the atmosphere via a radiator.
Stirling coolers were invented in 1816 by Reverend Robert Stirling, a Scottish clergyman, but were largely ignored until the mid 20th century, when their impressive energy efficiency became better known.
(Excerpt) Read more at space.newscientist.com ...
why Venus, with its runaway greenhouse effect, has become so different from Earth.
What is that thick atmosphere doing that close to the Sun?
Looks like the Venusian surface, but is the color right?
That’s one of the reasons for this type of mission... No one has a clue...
They don't think being much closer to the sun might have something to do with it?
“oh really............................ global warming has to fit into EVERYTHING!”
Venus’ atmosphere is due to an ancient race of SUVs that once roamed the planet.
It’s Bush’s fault. He ignored the obvious signs of Global Warming on Venus and DID NOTHING ABOUT IT. All those coal fired power plants and carbon producing autos all over the place on Venus, AND BUSH JUST IGNORED IT ALL. If Algore had won, boy, would things have been different. Venus would be a vacation spot.
“What is that thick atmosphere doing that close to the Sun?”
The first few extrasolar planets discovered were Jupiter-sized gas giants, as close as or even closer than Venus, so I guess it’s possible to keep your envelope in close.
The discovery of Venus’ CO2 atmosphere is actually the origin of greenhouse effect and global warming theory.
No, seriously, that atmosphere should have been blown off into space a looooonnnnng time ago.
Even distant Mars is a near airless rock. We barely have an atmosphere thanks to our magnetic sheild. Venus should be as airless as the Moon.
Is the sky really yellow all the time on Venus and is that a real photo or a mockup? How odd that would be if it is. Imagine waking up to a yellow sky. I wonder how many people would notice :-).
Interesting about that inventor, too. While I was skimming through that, it occurred to me I know very little about how and why my fridge works and acts as it does, not that I intend to explore that today. I take so much for granted with our conveniences.
It’s the temperature that a blackbody (epsilon=1) of equal diameter would have.
Earth’s equilibrium temperature is, I think, -16C (no greenhouse, just energy in- energy out)
Venus’ gravity is 9/10ths of Earth’s, while Mars’ is a bit over a third of Earth’s. Not an insignificant difference when comparing retention of atmosphere.
My guess would be a strong magnetic field.
Yes, if you have a huge mass, and strong magnetic field you can keep an atmosphere in close to a primary. (Also you are assuming that a Jovian mass planet is a gas giant, rather than a rocky giant)...
I think Venus has a strong magnetic field like earth and it helps prevent the atomsphere from being stripped away. Mars is on the other end of that scale.
Very true. But, given the differential strength of solar winds at Martian and Venereal(?) distances, the Venusian(?) atmosphere should be much thinner.
(What's the correct word for Venus related???)
Nope, humans done it. Billions and billions of greedy capitalist humans. No other possible explanation.
Venus has virtually no magnetic field - about a hundred thousand times smaller than Earth’s.
http://www.spacedaily.com/news/venus-05g.html
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