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."

No problem.

[dozer (30790)]

I've got an easier solution. Don't make the robot out of lead.

Re:

[DaleGlass (1068434)]

What will you solder the electronics with? Or what will you make them from for that matter?

Re:

[SydShamino (547793)]

Dude, no one uses lead for soldering any more.* Get with the times. [wikipedia.org]

* Except, ironically, NASA and the like, due to the tin whisker panic.**

** All the evidence I've seen is that tin whiskers are 99% a non-issue panic. The Wikipedia entry is definitely not NPOV with its inflammatory list of "nuclear power plant, satellites in orbit, aircraft in flight, and implanted medical pacemakers" for places that failures have been seen due to the phenomenon.

Re:

[s20451 (410424)]

All the evidence I've seen is that tin whiskers are 99% a non-issue panic.

Given that there are at least 100 nuclear reactors in the world, I'm not exactly reassured.

Re:

[mangu (126918)]

The Wikipedia entry is definitely not NPOV with its inflammatory list of "nuclear power plant, satellites in orbit, aircraft in flight, and implanted medical pacemakers" for places that failures have been seen due to the phenomenon

Would you consider it more NPOV if they stated that aunt Hilda's radio also failed because of tin whiskers? I don't think it's necessary to add irrelevant cases just to make it "neutral".

Re:

[SydShamino (547793)]

Would you consider it more NPOV if they stated that aunt Hilda's radio also failed because of tin whiskers? I don't think it's necessary to add irrelevant cases just to make it "neutral".

No, I don't think additional minor issues should be added. I think the examples included should be backed up by citation or removed. In this case, only the nuclear power plant has a citation, so the second sentence should be deleted entirely.

i've always said

[circletimessquare (444983)]

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

Re:

[calebt3 (1098475)]

Isn't Venus outside Sol's habitable zone? (the region around a star where liquid water is possible)

Re:i've always said

[larry bagina (561269)]

Prior to the global warming, Venus is generally believed to had surface water.

Re:i've always said

[evanbd (210358)]

Well, in terraforming terms, finding stuff to make up the Martian atmosphere probably isn't that hard. There are significant CO2 ice caps, and there may be significant water available with modest effort. CO2 plus plants gives you O2. Also, there is some good evidence to suggest that the icecaps' existence is bistable -- that is, if you could mostly evaporate them, the additional greenhouse effect would warm the planet enough to finish the job and keep it that way.

Basically, the problem of terraforming is to find resources that are already available in almost the form you want, and find some way to leverage your input effort. You don't want to have to process every single megaton of atmosphere you want to add / remove. It's far easier to (for example) dust carbon black on the poles and add a few orbiting mirrors.

Of course, the only reference I have handy is Zubrin's The Case for Mars which is a bit dated but (I think) still basically correct. The details may well have changed thanks to newer lander data.

Re:i've always said

[schnikies79 (788746)]

Isn't the problem with mars a lack of a magnetic field which allows the solar wind to strip away the atmosphere? I don't see how we could jump-start a magnetic field, so whats the point of even trying to rebuild the atmosphere if it's all going to blow away?

How about the lack of gravity? Can you build atmospheric pressure comparable to earth with lower gravity?

I saw Zurbin give a talk at my Univ a couple years ago and was going to ask him about it, but I forgot.

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[Tim C (15259)]

Can you build atmospheric pressure comparable to earth with lower gravity?

Probably. I wouldn't bet too much on necessarily being able to breathe the atmosphere though.

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[QuantumG (50515)]

Yes, but it takes thousands of years for the solar wind to blow away the atmosphere. If we one day have the ability to make the atmosphere of Mars suitable for human habitation then surely we will also have the ability to maintain the atmosphere over such a long time period.

all i'm saying is

[circletimessquare (444983)]

it is easier to destroy than it is to create

so with atmospheric density, it is easier to start some sort of process that would precipiate mass out of venus's atmosphere than it would be to bulk up mars somehow (and can mars' gravity hold the density?)

as for oxygen, i forgot about that (duh! ;-)

but getting oxygen (and water) in sufficient quantities is equally hard and daunting for mars or venus. venus has hydrogen and oxygen locked up just as much as mars does, and will require some chemical/ atomic manipul

how about nuclear winter?

[joggle (594025)]

I wonder how much Venus would cool if we simply dropped a couple hundred nukes on the surface. It would surely cool it by a few degrees, although I doubt it would cool it to anywhere close to comfortable temperatures.

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[Rakishi (759894)]

Well one idea for quickly thermoforming venus is to drop comets on it, broken up before impact to impact all their energy into the atmosphere. The idea being that the simplest method to get rid of the atmosphere is to simply blow it into space. Sadly it seems that the energy required would be quite a lot, as in you'd need to hit the planet with a lot of comets or whatever other space junk you find.

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[John Hasler (414242)]

> I wonder how much Venus would cool if we simply dropped a couple hundred nukes on the
> surface. It would surely cool it by a few degrees...

More likely a few hundredths of a degree, but why do you think that would cool it at all?

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[CorSci81 (1007499)]

Actually, Mars has lost a significant amount of hydrogen (as has Venus, but not as severely) and most of the surface rocks are highly oxidized. Really, you'd need to add back some hydrogen to make Mars really work. And as far as the radiation goes, Earth's atmosphere (and also Venus's) do a LOT to stop radiation. Sure it doesn't get all of it, but astronauts on the space station are getting a much higher radiation dose than you and I down at ground level.

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[inviolet (797804)]

Well, in terraforming terms, finding stuff to make up the Martian atmosphere probably isn't that hard. There are significant CO2 ice caps, and there may be significant water available with modest effort. CO2 plus plants gives you O2. Also, there is some good evidence to suggest that the icecaps' existence is bistable -- that is, if you could mostly evaporate them, the additional greenhouse effect would warm the planet enough to finish the job and keep it that way.

Eh... better to leave Mars alone. It will

Re:

[jimbojw (1010949)]

but however you do it, it's an easier starting scenario than mars

That's ridiculous - everyone knows that as soon as Quaid activates the turbidium reactor, Mars' atmosphere will fill out nicely.

Re:i've always said

[Average_Joe_Sixpack (534373)]

i don't know. but however you do it, it's an easier starting scenario than mars

Probably not due to the 243 day rotation.

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[Daimanta (1140543)]

But it has GREAT all night parties!

uneven heating meets atmosphere

[circletimessquare (444983)]

and you get wicked weather at the night/ day interface, a blistering midday, and a chilling midnight. but it won't be as wicked a change as on mercury, because the atmosphere will conduct some heat (little, yes, but some is better than none)

and even with day length considered, venus is still ahead of mars, considering all the other variables, mars comes out a worse prospect still

but you are correct to point out that day length is a big impediment, i forgot to address that

Re:

[DerekLyons (302214)]

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'.

In some magical universe where you can safely sequester the billions of tons of carbon that will have to

Re:

[CorSci81 (1007499)]

Well, Earth has managed to safely sequester billions of tons of carbon. We have just as much of it as Venus, ours just happens to be locked up in nifty things like carbonate rocks. Venus could have carbonate rocks too if we could just get it a little cooler and get some water back on the surface to help with erosion. Just at present the reaction goes the wrong way and you have CaCO3 + SiO2 -> CaSiO3 + CO2, so there aren't a lot of carbonate rocks laying about. In terms of atmospheric composition if y

Re:

[flyingsquid (813711)]

but at the same time, ask a roman general 2,000 years ago to consider the existence of jet fighters, air craft carriers, and helicopters and you would get the same level of incredulity as you have now about being in a "magical universe" which means his problem, and your problem, is that you lack imagination. you're a dullard. you think pointing out that terraforming planets is difficult is a useful comment to make

All the example of the Roman general proves is that it's not a good idea to make predictions,

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[Loke the Dog (1054294)]

They both lack magnetic fields which makes long term terraforming pointless which means we can just drop the whole idea.

magnetic fields are good for block radiation

[circletimessquare (444983)]

there are many ways to block radiation

but obviously, you are correct to point out this is a major impediment. but beggars can't be choosers. i don't see any other small rocky orbs close by to consider. mercury is way worse, and the gas giants are, well, gas giants, and their moons are too cold

Length of days is a problem

[mangu (126918)]

if you want to talk about recreating earthlike conditions (water, temperature, gravity, atmospheric density)

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 th

Re:

[mbone (558574)]

The length of day isn't really a problem.

Venus had a habitable climate for billions of years. If you get the CO2 out of the air and back into the rocks, like on Earth, it could again, long length of
day or not. BTW, there are lots of people who live in arctic areas with roughly similar day / night distributions.

However, if you really needed to, you could hit the planet with a carefully aimed ice rich asteroid or (better yet) a comet. This would both add water and change the spin, in principle to whatever yo

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[edwardpickman (965122)]

The real truth is all the other inner planets suck as terraforming cannidates. Mars is realitively benign compared to Venus. Its the high content of sulfuric acid that would hamper terraforming. Shifting the orbit to Earth orbit might help with the greenhousing and it might be possible to blast away part of the atmosphere but removing large amounts of sulfuric acid is going to be trickier. The concentrations are high enough to erode mountains on Venus. Mars may lack a dense atmosphere and has low gravity bu

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[JebusIsLord (566856)]

You can't just precipiate it out... I remember reading in (I think) some Carl Sagan book long ago, that if we did so, they'd end up with a layer of charcoal a few feet deep, plus around a hundred atmospheres of pure oxygen. Someone lights a match, and you're back to square one.

His best analysis was that we'd have to blow the atmosphere off by hitting the planet with asteroids. Not exactly as easy feat.

Re:

[by Anonymous Coward]

So you'd get a planet full of people predisposed to have big appetites, and have them breed.
I'd get pretty scared once they get a taste for Terran ribs and start hunting us for food from their flying saucers.

With apologies to obese people. I suck.
(And I taste bad.)

Isn't It Obvious

[Nom du Keyboard (633989)]

Isn't it obvious. Venus is Global Warming run amuck. And we're next!

Stirling coolers

[EaglemanBSA (950534)]

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 [coleman.com] 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.

Re:

[Geoffrey.landis (926948)]

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).

... and, in fact, Global Cooling licensed their free-piston Stirling engine technology from Sunpower (also of Athens, Ohio), and Sunpower works with NASA Glenn on the Stirling engine development. So they really are the cousins of the Venus engines.

If Stirling Coolers are so efficient

[JumperCable (673155)]

If Stirling Coolers are so efficient, why are we not using them to cool our homes & office buildings?

Re:Stirling coolers

[EaglemanBSA (950534)]

No, actually they're using the stirling design as the actual pump - that's the beauty of it. They're looking at using CO2 or helium as the refrigerant as well as the working fluid in the stirling cooler - especially with respect to helium, getting the gas-phase bubbles out of the fluid is as simple as letting it evaporate and leak back into the cooler itself. The design is much simpler this way, and leaks are quite benign.

That being said, helium is a bit more expensive than other refrigerants, and CO2 requires intensely high pressures, so much work is yet to be done. As a heat pump, Stirling cycle engines operate on the theoretical threshold (we evaluate them using the Carnot cycle) of efficiency, so they...well, blow other designs out of the water. For numbers, I don't have any here. To give you some perspective though, I've seend a 40 watt unit freeze the water in the air around it within seconds of being turned on.

ROHS

[Biff Stu (654099)]

Now that everybody has made the shift to ROHS electronics, who cares if the heat melts lead? They should be able to do it with all COTS parts.

1970's refrigerator?

[downix (84795)]

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).

From the Stirling Engine article

[AnonymousCactus (810364)]

Yeah, an engine, sure: http://en.wikipedia.org/wiki/Image:BetaStirlingTG4web.jpg [wikipedia.org]

The real test

[kaoshin (110328)]

Yes, but can this device provide adequate cooling for a pair of NVIDIA 8800's in a brutal "room temperature" environment?

I would rather put a Stirling on Venus...

[rholland356 (466635)]

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.

Albert Einstein invented a safer refrigerator

[MichaelCrawford (610140)]

Back in his day, refrigerators used gaseous ammonia as the refrigerant, which is highly toxic. He was appalled to hear of a whole family being killed by a leaky refrigerator, so he and Leo Szilard invented one [wikipedia.org] that had no moving parts, and thus without the risk of leaky seals.

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.

Welcome!

[Tablizer (95088)]

We at Venus welcome your cool beer-carrying roverlords. We're damned thirsty over here.

Re:

[Geoffrey.landis (926948)]

Water lowers the viscosity of magma.

Venus' landscape is awesome

[amightywind (691887)]

Wouldn't the rover just beam back "It's hot and everything's melted" over and over lol. If I remember correctly, there's no significant features to even study. You can't have mountains and ancient, dried up rivers and caves when everything's that hot. Mars is far more interesting.

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 tempe

Pseudoscience

[MaDeR (826021)]

Funny that many people mistake mythology with factual history... you also think that x-files are documentary, aren't you?

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 [wikipedia.org]

http://skepdic.com/velikov.html [skepdic.com]

"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?

Re:The Fraud of Venus' Supposed Thermal Equilibriu

[meringuoid (568297)]

(a) A satellite on the dark side of Venus beamed a light towards Venus and measured how much of that light returned, or (b) A satellite on the light side of Venus simply turned the instrument towards the Sun and then towards Venus, and computed a ratio of the light intensities.

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.

Re:

[MLease (652529)]

4. Venusian scientists terraformed Earth

Wouldn't that be veneraformed or something?

Also, you forgot: 7. ??? and 8. Profit!

-Mike