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Hot space bot uses stirling engine
November 12, 2007 12:24 PM   Subscribe

NASA proposes using a Stirling cooler (essentially a Stirling engine in reverse) to keep a probe cool on the surface of Venus, which has had a tendency to melt or smash previous probes. The cooler would maintain a 25cm sphere within the probe at 200°C -- 100°C above the boiling point of water but sufficiently cool for a high-temperature microcontroller to operate. The waste heat radiators on the exterior of the sphere would reach the temperature of 500°C, 40°C above the the normal Venusian surface temperature.
posted by Artw (40 comments total) 4 users marked this as a favorite

 
Previously on metafilter
posted by Artw at 12:25 PM on November 12, 2007


Because this new heat pump design keeps the thermal enclosure at a moderate temperature, it is now possible to plan missions to explore the most hostile environment in our Solar System: the surface of Venus.

More hostile then the surface of the sun?
posted by delmoi at 12:32 PM on November 12, 2007


Venus.
posted by psmealey at 12:34 PM on November 12, 2007


More hostile than Jupiter?

But still, I support any whacked-out probe thingy NASA can dream up.

Seriously though, Jupiter doesn't even let you get close enough to be crushed by pressure or asphyxiated or frozen or melted. THat's hostile.
posted by Mister_A at 12:37 PM on November 12, 2007


Cool.
posted by flippant at 12:37 PM on November 12, 2007


Also previously on metafilter.
posted by Artw at 12:41 PM on November 12, 2007


Neither the Sun nor Jupiter has a surface. They are gas balls. You can't land a rover on either. You can fire a probe to fly around but it will need too much propellant to "rove" around in the atmospheres of the Sun or Jupiter.

I loves me my space probes.
posted by Ironmouth at 12:42 PM on November 12, 2007


it is now possible to plan missions to explore the most hostile environment in our Solar System

Just sayin'. It may be one of the more hostile SURFACES, but it's pretty vanilla when it comes to highly lethal environments. Death to hyperbole!
posted by Mister_A at 12:44 PM on November 12, 2007


Jupiter has a surface down there somewhere, possibly with lakes of metallic hydrogen, which is actually pretty awesome.
posted by Artw at 12:46 PM on November 12, 2007


More hostile then the surface of the sun?

Apparently less hostile than MetaFilter comments.
posted by GuyZero at 12:47 PM on November 12, 2007 [2 favorites]


Jupiter is the New England Patriots of planets, is the thing.
posted by Mister_A at 12:47 PM on November 12, 2007


Wait, so how did those Soviet Vanera probes manage to land and send back data? Really hot vacuum tubes?
posted by GuyZero at 12:50 PM on November 12, 2007


...it is now possible to plan missions to explore the most hostile environment in our Solar System...

More hostile then the surface of the sun?

The sun is hotter, but to be honest, Venus' neighborhoods are way more dangerous. There are some areas that you just don't want to be seen, let alone get out of your car.

It's like a warzone.
posted by quin at 12:50 PM on November 12, 2007


I think they worked for a minute and then went BZZZT! and then melted. Seriously.
posted by Mister_A at 12:51 PM on November 12, 2007


"Whether they ever find life there or not, I think Jupiter should be considered an enemy planet."

-Jack Handy
posted by inconsequentialist at 12:52 PM on November 12, 2007 [1 favorite]


I'm surprised that they didn't figure out a way to harness all that ambient heat energy to power the engine, rather than haul along plutonium. I suppose the radiators won't radiate unless they are hotter than the atmosphere?
posted by Camofrog at 12:54 PM on November 12, 2007


Google up Landis's "colonization of venus". The floating cities idea is the coolest damn thing I've heard of in years.
posted by a robot made out of meat at 1:01 PM on November 12, 2007 [1 favorite]


This would be so cool. I spent many hours as a lad daydreaming about what the surface of Venus looks like. The atmosphere is impenetrable to cameras, and the only surface probe ever landed there lasted no more than 10 minutes (with a camera lens that was made out of diamond!). Well maybe it wasn't the only one, but there's something just plain maddening about the mystique and impenetrability of our sister planet. It's so close by, and yet we know so little about it compared to Mars, where our rovers can go have a little robot field day until their batteries run out.

I had a science teacher once who hammered home the sheer amazingness of our existence here for me by comparing Earth to the planets around us in the solar system: 30,000 miles closer to the sun and the Earth's environment could have been inhospitable like Venus'; 30,000 miles further away and Earth could have wound up resembling Mars, not as hostile but equally incapable of supporting life. The fact that our planet exists in that tiny little belt wherein life as we know it can exist is a thing of wonder.
posted by baphomet at 1:05 PM on November 12, 2007


I'm surprised that they didn't figure out a way to harness all that ambient heat energy to power the engine, rather than haul along plutonium. I suppose the radiators won't radiate unless they are hotter than the atmosphere?

Second Law of Thermodynamics says that any heat engine requires a differential in temperature. The Carnot cycle requires a transfer of heat from a hot reservoir to a cooler reservoir. If everything is the same hot ambient temperature, you cannot do any useful work.
posted by JackFlash at 1:12 PM on November 12, 2007


S.M. Stirling (AFAIK no relation to the reverend Stirling) has some interesting sounding books set on a Venus that turns out not to be hot enough to boil lead or have an atmosphere made out of sulphuric acid, and instead is Edgar Rice Burroughs style jungles and dinosausrs.
posted by Artw at 1:13 PM on November 12, 2007


Images of Venus
posted by homunculus at 1:15 PM on November 12, 2007


The fact that our planet exists in that tiny little belt wherein life as we know it can exist is a thing of wonder.

No doubt. Then again, there are billions of solar systems in the universe where all the planets are outside that little life-sustaining belt, and there's nobody there to complain about it. (Kinda like the Weak anthropic principle...)
posted by LordSludge at 1:22 PM on November 12, 2007


I read a book called Dragon's Egg, by Robert Forward, that was all about aliens living on a neutron star, a most hostile environment to people, but not to the critters who lived there. Point being, one should avoid extra-terrestrial chauvinism in defining where life can and can't occur. I do not believe that life can only arise in earth-like environments; I believe earth-like life needs earth-like environs, but that other creatures may arise in other environs.

That said, after we get done with Iran, let's attack Jupiter!
posted by Mister_A at 1:31 PM on November 12, 2007 [3 favorites]


No doubt. Then again, there are billions of solar systems in the universe where all the planets are outside that little life-sustaining belt, and there's nobody there to complain about it.
Not only that, but suppose something had evolved in one of those, but was unable to live in conditions that were very slightly different from the ones it was used to. Then, by the same logic, IT could say "Wow, how amazing it is that I managed to evolve at all!"
This is like picking a random number between one and a billion, then saying "How amazing that I should get 3,729,483! The odds against that are one in a billion!"
I'm not saying that life is guaranteed to evolve in the universe, but so far we have thoroughly explored one planet, and it has life on it. Our sample size is not sufficient to make claims about how likely or unlikely that one event was.
posted by agentofselection at 1:40 PM on November 12, 2007 [2 favorites]


Wait, so how did those Soviet Vanera probes manage to land and send back data? Really hot vacuum tubes?

Yes. Basically. The Wikipedia articles on the Venera probes are pretty good, if you're interested -- mostly what they did was just massively overbuild them (think inches upon inches of steel or titanium), then pre-chill them with cryogenic fluids before they dropped them into the atmosphere.

Several didn't even make it to the surface; they died en route in the atmosphere (due to the pressure). But even the longest-lived ones were only operational for short durations.
posted by Kadin2048 at 1:51 PM on November 12, 2007


Cool post.
posted by BackwardsHatClub at 1:55 PM on November 12, 2007


NSFW?
posted by caution live frogs at 1:58 PM on November 12, 2007 [2 favorites]


baphomet: I think you mean 30,000,000 miles. The earth's distance to the Sun varies by 4 million miles over the course of a year.
posted by Laen at 2:00 PM on November 12, 2007


Point being, one should avoid extra-terrestrial chauvinism in defining where life can and can't occur. I do not believe that life can only arise in earth-like environments; I believe earth-like life needs earth-like environs, but that other creatures may arise in other environs.

I completely 100% agree with you. Which is why I included the "as we know it" qualifier. I realize that there may be forms of life or what would be considered life that could potentially exist in forms incomprehensible to us currently, which exist in environments we believe to be inhospitable- but for the purposes of discussing life in the universe this is something like throwing our hands in the air and saying, "Whatever." I think that when we're discussing the metaphysics of life, as well as extraterrestrial life, our existence is the best blueprint we have to go on, and it's useful on a very basic level to utilize that stricture in order to proceed with such considerations.

baphomet: I think you mean 30,000,000 miles. The earth's distance to the Sun varies by 4 million miles over the course of a year.

You're right, I do. Thank you for the correction. I have enough difficulty pointing to something 30 feet away, much less talking about things several orders of magnitude larger, and I've been out of the science loop for long enough that the old bear trap is getting rusty.
posted by baphomet at 2:14 PM on November 12, 2007


baphomet: I had a science teacher once who hammered home the sheer amazingness of our existence here for me by comparing Earth to the planets around us in the solar system: 30,000 miles closer to the sun and the Earth's environment could have been inhospitable like Venus'; 30,000 miles further away and Earth could have wound up resembling Mars, not as hostile but equally incapable of supporting life. The fact that our planet exists in that tiny little belt wherein life as we know it can exist is a thing of wonder.



The distance isn't so much the deciding factor as the atmospheric composition and a magnetosphere which decide if humans can live there. Both Venus and Mars are eminently habitable by humans with the right kind of atmosphere. The interesting thing is that it's quite possible that both planets probably at some time in their history were capable of supporting human life. It still is a pretty incredible set of circumstances that need to be in place for human life to be supported.
posted by BackwardsHatClub at 2:27 PM on November 12, 2007


I read a book called Dragon's Egg, by Robert Forward, that was all about aliens living on a neutron star, a most hostile environment to people, but not to the critters who lived there.

Love that book!
posted by The Light Fantastic at 2:32 PM on November 12, 2007


Where there is beer, there is life.
posted by Mister_A at 2:32 PM on November 12, 2007


...I essentially a Stirling engine in reverse...

That has to be a joke, right? Nothing could look that much like a penis. That has to be wikipedia vandalism or something, right?

I mean, the diagram states that the shaft is the 'Hot Cylinder Wall' and it's got a piston going up and down it... and... I mean...

wow. I don't know what to say. It seems to be a very effective machine.

*speechless*
posted by Alex404 at 2:34 PM on November 12, 2007 [2 favorites]


The distance isn't so much the deciding factor as the atmospheric composition and a magnetosphere which decide if humans can live there.

My understanding is that distance from the sun has a big impact on those factors, although obviously there are a million other factors that influence this (such as the planet's composition, moons, rotational velocity, etc etc). The way it was explained to us was that we're in the primo spot temperature/sunlight exposure-wise to support life as it is known, and that the changes in proximity to the sun's heat and light are major factors in determining the other things like atmospheric composition that have such a huge bearing. Of course, this is a very elementary understanding of the subject material and I could be way off the mark.
posted by baphomet at 2:36 PM on November 12, 2007


Yeah, I'm not a planetary scientist either, but my understanding is that, for instance, if Mars still had an active magnetic core it might still have an atmosphere substantially similar to earth's. Earth lies within the habitable zone, and so by our definition has the best chance to support life, but I think we may see that definition expand in the future.
posted by BackwardsHatClub at 2:43 PM on November 12, 2007


We could pipe in some Coltrane. Live at the Village Vanguard should keep the probe really cool. (Disclaimer: IANARS)

“Seriously though, Jupiter doesn't even let you get close enough to be crushed by pressure or asphyxiated or frozen or melted. THat's hostile”

Well, if you had a controling bitch for a wife you’d be pretty hostile too.
(the asphixiation thing was consentual btw, as was the chains and anvils)

“The fact that our planet exists in that tiny little belt wherein life as we know it can exist is a thing of wonder.”

Not to mention Earth’s internal heat and many other factors - really we live in about a 2 to 5 mile range (vertical) where we can exist. We’re roughly 2-5 miles from death no matter where on the earth we are (5 miles up, you die, 5 miles down, you die, typically much much less)
That’s really, really small in comparison.
posted by Smedleyman at 3:26 PM on November 12, 2007


may be able to be adapted to other missions, such as near-Sun missions, Mercury surface robots, and volcano exploration.

Now we're talkin'!
posted by cowbellemoo at 10:05 PM on November 12, 2007


why dont we just build a dyson sphere inside the orbit of mercury, wait for the planets to cool and then explore them?
posted by blue_beetle at 11:12 PM on November 12, 2007


CoolTools featured a version of this technology made for an even more alien environment - - the tailgate party...

Ladies and gentlemen, I give you the Coleman Stirling Electric Cooler!
posted by fairmettle at 9:31 AM on November 13, 2007


Venus: Earth’s twin planet?
posted by Artw at 10:22 AM on November 29, 2007


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