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Momentum is building to explore Venus

nature.com

71–80 of 179 posts

Re: Momentum is building to explore Venus

#71
post #60

Why couldn't you vacuum insulate the electronics and place some kind of radiative cooling on top of them? You'd need the cooler to be able to radiate all the radiative energy coming into the chamber from outside it, plus what the electronics generate. You'd want the thermos type chamber to be reflective to radiation from one side only. It would depend on how low energy you can get the electronics, plus how efficient…

> Why couldn't you vacuum insulate the electronics and place some kind of radiative cooling on top of them?

Radiative cooling only works if you have a hot source and a relatively cooler sink - on Earth, usually the atmosphere.

On Venus the atmosphere is ~462 °C at the surface, so it's going to be much hotter than your electronics - so your sink will be hotter than your source, so the "raditaive cooling" will run in reverse.

Also, the atmospheric pressure on Venus is very high - 92 atmospheres at the surface - the equivalent of being 1km underwater on Earth. Maintaining a vacuum chamber with this much outside pressure (not to mention temperature) would be an incredible feat of materials engineering - and would probably by extremely heavy.

You would also still need sensors and communications outside your vacuum chamber, otherwise your expensive probe can't actually do anything useful.

Re: Momentum is building to explore Venus

#73

I wonder why there isn't a balloon mission being studied. The upper atmosphere has temperature and pressure similar to Earth at sea level. Maybe the wind is a big problem? Or insertion from orbit?

I know this isn't what you mean by "studied," but here's a NASA produced video mockup of manned blimps over Venus: https://youtu.be/0az7DEwG68A

Re: Momentum is building to explore Venus

#74
post #32

Stay tuned for the Venus mechanical maker challenge: https://www.jpl.nasa.gov/edu/events/2019/3/1/mechanical-make... >With its sulfuric acid clouds, temperatures over 450°C, and 92 times the surface pressure of Earth, Venus is one of the most hostile planetary environments in the solar system. Prior missions have only survived hours! But an automaton (or clockwork mechanical robot) could solve this problem. By utiliz…

From the link:

> ... at the Glenn Research Center. > > The team has already tested the circuits in a Venus simulation chamber — a 14-tonne stainless-steel tank that can imitate the temperature, pressure and specific chemistry of the Venusian surface.

Re: Momentum is building to explore Venus

#75

I wonder why there isn't a balloon mission being studied. The upper atmosphere has temperature and pressure similar to Earth at sea level. Maybe the wind is a big problem? Or insertion from orbit?

From the link:

> This year, the Venera-D team released a report that covered a number of potential additions, including a balloon that could explore the cloudy atmosphere.

Re: Momentum is building to explore Venus

#76
post #63

Earlier quoted context omitted.

well you said it: we know exactly how to heat up mars (greenhouse gases) but its not so clear how to cool down venus. also mars has water.

We don't need to cool it down. We could float a platform about 49.5 km above the surface of Venus, where the temperature and pressure nearly match the earth at sea level. To launch a probe, we could simply drop it from the platform. This article about Venus is very enlightening: https://en.wikipedia.org/wiki/Atmosphere_of_Venus

We don't need to cool Venus down, but in a few hundred years we might need to cool the earth, so learning how to do that on Venus might be a good idea.

Re: Momentum is building to explore Venus

#77
post #63

Earlier quoted context omitted.

well you said it: we know exactly how to heat up mars (greenhouse gases) but its not so clear how to cool down venus. also mars has water.

We don't need to cool it down. We could float a platform about 49.5 km above the surface of Venus, where the temperature and pressure nearly match the earth at sea level. To launch a probe, we could simply drop it from the platform. This article about Venus is very enlightening: https://en.wikipedia.org/wiki/Atmosphere_of_Venus

my comment was in response to parent saying venus was a better candidate for colonization than mars.

but i am totally on board with exploring venus, although im not convinced the atmospheric issues are significantly lesser than the surface, just different (hurricane winds, sulfuric acid, etc)

Re: Momentum is building to explore Venus

#78
post #69

Because of Venus's think atmosphere, landing a probe or rover is really easy. The downside, also because of Venus's thick atmosphere, is that the surface is really, really hot. That limits the lifetime of hardware on the surface. I think it ought to be possible to design a probe that's more like a submersible than a rover. Technically it would be an airship rather than a submarine, but given Venus's thick atmosphere…

An airship seems like the most survivable option for longer missions.

I wonder if it would be possible to use one as a carrier for smaller drone-ships. Wind speeds on Venus are quite low, but the force is probably quite insane considering the atmospheric pressure.

Re: Momentum is building to explore Venus

#79
post #34

So I had two thoughts while reading it: Is it possible that in the 3 billion years that it had liquid water, Venus evolved advanced life that managed to trigger runaway greenhouse warming? Secondly, is Venus’s atmosphere a worst case scenario for global warming here or is there something that would prevent it happening?

I see no reason why intelligent life with high technology could not have developed on Venus. Say, several hundred million years ago. And perhaps they triggered runaway greenhouse warming, which vaporized the oceans. And so perhaps it was the loss of the oceans that ended plate tectonics, not the other way around. I doubt that runaway greenhouse warming could get so extreme for Earth. I recall reading that solar input…

> I see no reason why intelligent life with high technology could not have developed on Venus. Say, several hundred million years ago. And perhaps they triggered runaway greenhouse warming, which vaporized the oceans. And so perhaps it was the loss of the oceans that ended plate tectonics, not the other way around.

The only way that thought experiment could make sense is if they had the technology to do that, but not the technology to escape Venus and get to Earth.

Think about it; several hundred million years ago, Earth was habitable; maybe not for modern humans (but I bet we could do it - though uncomfortably), but definitely life existed in some form:

https://en.wikipedia.org/wiki/Age_of_the_Earth

So there was liquid water, and the Earth wasn't a Dante-esque hellscape of volcanos and lava, etc. It was probably much warmer and more humid, but overall not crazy to live on.

So if your situation was dire enough, and you had the technology to escape the planet (which you'd almost have to, if you had the energy resources to cause your own global warming and demise scenario) - wouldn't you at least try?

So either they tried and failed in some manner (never reaching Earth), or they succeeded (meaning?) or something in between.

Even if they didn't try, with the level of technology, wouldn't they at least have left something behind in the solar system that we'd recognised as created by intelligent life long ago? Some artifact somewhere?

Maybe they did, and we haven't found it (space is big - the solar system is a big place); but I'd almost expect there'd be something orbiting Venus that was artificial (though maybe again, we can't detect it from here - too small, likely inactive, etc). I guess a good question would be, if you were on Venus (or even in Venusian orbit) - could you detect Earth's satellites currently orbiting Earth? Could you detect a singular one (last of its kind) in a degraded, virtually inert state? Again, I don't know.

It's a bit fascinating to think about; part of me wants to say "we should be able/have found something by now" if such a scenario were real - but at the same time, I can think of reasons why we haven't or can't...

Re: Momentum is building to explore Venus

#80
post #63

Earlier quoted context omitted.

well you said it: we know exactly how to heat up mars (greenhouse gases) but its not so clear how to cool down venus. also mars has water.

We don't need to cool it down. We could float a platform about 49.5 km above the surface of Venus, where the temperature and pressure nearly match the earth at sea level. To launch a probe, we could simply drop it from the platform. This article about Venus is very enlightening: https://en.wikipedia.org/wiki/Atmosphere_of_Venus

How would we float a platform at that height?
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