Manned Venus Landing

[Xannari Ferrows]

Venus has a thick atmosphere and gravity that is almost as great as Earth's. So you would also have to have an ascent stage, making the engineering challenges even more insurmountable.

You would need VERY ROUGHLY 6.8 Km/s Delta-V. This was like a 7 second calculation, so it could be off by a fair amount.

[K^2]

You would need VERY ROUGHLY 6.8 Km/s Delta-V. This was like a 7 second calculation, so it could be off by a fair amount.

I'm getting ~3.5km/s of dV for atmo/grav losses + 7.4km/s to orbit with no significant benefits to equatorial launch. So a launch from Venus should be achivable with 11km/s rocket against 9km/s for launch from Earth.

I'm using an extremely simple model for the aero/grav losses, though. Could easily be off by enough to agree with your estimate.

[Reddragon]

Even if we could land humans on the surface Venus, it would be the last place I'd go for sure. Also, who would want to live in an airship/airplane flying constantly above hell? I'm pretty sure sometime in the future there are going to be science missions to Venus but I can't imagine crowds moving there for a colony.

[Xannari Ferrows]

I'm getting ~3.5km/s of dV for atmo/grav losses + 7.4km/s to orbit with no significant benefits to equatorial launch. So a launch from Venus should be achivable with 11km/s rocket against 9km/s for launch from Earth.

I'm using an extremely simple model for the aero/grav losses, though. Could easily be off by enough to agree with your estimate.

I guess it also depends on your TWR. You'll take less gravity losses with a higher amount, but you already knew that, so... Redundancy!

I guess I never factored in a proper result for drag forces. All I did was an average, and accounted for lift afterwards. Maybe I should try from ALT 0.01 as well.

[K^2]

Also, who would want to live in an airship/airplane flying constantly above hell?

Yet you seem to be comfortable enough floating on a piece of rock over molten magma. With a large enough platform, what's the difference?

I guess it also depends on your TWR. You'll take less gravity losses with a higher amount

Up to a point. Then you start just wasting fuel fighting excessive drag. My estimate assumes quadratic drag, which requires TWR in 2-3 range through most of the ascent.

[Skyler4856]

Yet you seem to be comfortable enough floating on a piece of rock over molten magma. With a large enough platform, what's the difference?

If you poke a hole in this platform, you dont die.

[Reddragon]

I guess it also depends on your TWR. You'll take less gravity losses with a higher amount, but you already knew that, so... Redundancy!

I guess I never factored in a proper result for drag forces. All I did was an average, and accounted for lift afterwards. Maybe I should try from ALT 0.01 as well.

It depends quite much on your TWR I guess. You definitely don't want to spend too much time fighting gravity in the lower atmosphere.

Yet you seem to be comfortable enough floating on a piece of rock over molten magma. With a large enough platform, what's the difference?

I hope you were joking... Yes, I feel very confortable here especilly compared to a flying bunker which can actually fall down unlike this 'platform'.

Edited May 17, 2015 by Reddragon

[Xannari Ferrows]

Up to a point. Then you start just wasting fuel fighting excessive drag. My estimate assumes quadratic drag, which requires TWR in 2-3 range through most of the ascent.

Well, I did say gravity... More so applies to moons or dwarf planets.

Well, maybe the Delta-V just varies from craft to craft. A space bowl needs more Delta-V to counteract air-resistance, and the needle that I assumed, not so much.

I'll have to go grab some more paper. Wasted it all earlier...

Well, I implemented a proper aerodynamics function. Arrived at about 9.4 Km/s, so I guess about average for our estimates.

If you poke a hole in this platform, you dont die.

Really? I thought you would get consumed by Magma and whatnot...

Edited May 17, 2015 by Xannari Ferrows

[K^2]

Yes, I feel very confortable here especilly compared to a flying bunker which can actually fall down unlike this 'platform'.

We have people dying by thousands from earthquakes and other tectonic events every year. That's safe? We can seriously do better than that with an artificial colony on Venus.

[khh]

We have people dying by thousands from earthquakes and other tectonic events every year. That's safe? We can seriously do better than that with an artificial colony on Venus.

If we could do better, people would not be dying by the thousands (which I believe is a gross exaggeration) every year on Earth, where our ability to build and monitor is the greatest.

[Jonboy]

We have people dying by thousands from earthquakes and other tectonic events every year. That's safe? We can seriously do better than that with an artificial colony on Venus.

Suspended in clouds of sulferic acid dozens of miles above the most inhospitable solid planet in the solar system is better than standing on the ground on Earth? I mean yeah, natural disasters happen on Earth but it's still safer than a Venus cloud colony could be for a long time.

[Reddragon]

We can seriously do better than that with an artificial colony on Venus.

The problem is that it's still completely science fiction.

[K^2]

If we could do better, people would not be dying by the thousands (which I believe is a gross exaggeration) every year on Earth, where our ability to build and monitor is the greatest.

They aren't really dying by thousands in civilized countries where things are built properly, but there are still deaths with major earthquakes anywhere on the planet. We cannot avoid it when we build on tectonic plates. And don't even start me about potential "near future" disasters such as The Big One or the Yellow Stone. Living on this planet is incredibly dangerous.

If we build a floating colony on Venus, I can absolutely guarantee that it will be safer than most places on Earth are right now, and in the long run, we could make it safer than any place on Earth.

We can improve safety on Earth too, of course. Get it to the point where either one is as safe as anyone could ask for. But you know it's not going to happen on Earth. We'll just keep going the way we are. And so if you accept life on this planet as "reasonably safe," complaining about potential Venusian colony is just absurd.

[Kryten]

Step 1:

And CO2 is poisonous at very high concentrations.

One could not breathe an atmosphere that is 80% CO2, 20% O2... at 1 atm

More like 8%, at least for any significant length of time. Respiratory acidosis is not pleasant.

[baggers]

What's the point of a flying Venus colony nowaday?

I mean, catching sulfurics cloud with a butterfly net is certainly a respectable hobby for some scientist with dirty hairstyle, but what else, the hell, can you do in that sort of place?

[K^2]

You can live there, be self-sufficient, and expand the colony. What are other requirements for a colony?

[Borklund]

What's the point of a flying Venus colony nowaday?

I mean, catching sulfurics cloud with a butterfly net is certainly a respectable hobby for some scientist with dirty hairstyle, but what else, the hell, can you do in that sort of place?

There is no point to a flying Venus colony, it's all science fiction make believe. Mars provides an infinitely better environment in which to settle humans. A 30-day manned research mission to Venus however, would be nice to have.

But even something like this is completely beyond the capability of NASA at the moment and in the foreseeable future. A mission like the one in the video would require research, design, building and testing many incredibly complicated pieces of hardware. NASA does not exactly have tens of billions of dollars lying around.

You can live there, be self-sufficient, and expand the colony. What are other requirements for a colony?

[Citation needed]

[baggers]

You can live there, be self-sufficient, and expand the colony. What are other requirements for a colony?

Mining, trading, gib clay and mony/slaves/goods to motherland. The usual stuff.

Maybe a penitenciary colony?

[Jonboy]

You can live there, be self-sufficient, and expand the colony. What are other requirements for a colony?

No, you can't be self-sufficient. There's an absolute dearth of usable resources. There are no incentives to live in a Venus airship except scientific research.

A 30-day manned research mission to Venus however, would be nice to have.

Again, this is the only reason to live on Venus. But, as you pointed out, the challenges are significant and beyond our present abilities.

[K^2]

No, you can't be self-sufficient. There's an absolute dearth of usable resources.

If you need something beyond carbon dioxide and water vapor to be self-sufficient, you're doing it wrong.

[Jonboy]

If you need something beyond carbon dioxide and water vapor to be self-sufficient, you're doing it wrong.

That has yet to be demonstrated. Nobody's ever built a system with no inputs but H2O and CO2 that can sustain life long-term.

Edit: I'm not saying it's impossible I'm just saying it's really, really tough. And clearly beyond our current abilities.

Edited May 17, 2015 by Jonboy

[K^2]

If we start taking off the table everything that has not yet been demonstrated, we can only speculate that people will keep doing what they are doing now and nothing new. Which is silly.

That said, binding CO2 from atmosphere into useful hydrocarbons under sunlight has been demonstrated. And from there on it's standard petrochemical to get any plastics known to man as well as carbon fiber and numerous other materials. So we have construction covered. Likewise, sunlight, CO2, and water is basically all that the plants need in abundance. All of the above also needs a bit of nitrogen, which is also present in atmosphere. Almost everything else is only needed in trace amounts.

There are vital minerals that would be almost impossible to replace. But they are needed for life and construction in such small quantities that they can be actually mined for despite horrible conditions and expense of doing so. Of course, it'd probably be way cheaper to get them from off-world. Ideally, I'm picturing such a colony supplemented with Lunar or asteroid mining to deliver small quantities of metals and minerals needed for nutrition supplements and industry. But if it has to be an entirely closed system this can still work.

[Borklund]

If we start taking off the table everything that has not yet been demonstrated, we can only speculate that people will keep doing what they are doing now and nothing new. Which is silly.

Yes but on the flipside, if you handwave practical, economical and political hurdles why not just build an interstellar warp drive and go find an Earth twin that is better than Earth in every single way and relocate the entire population of Earth there? There is no self-sustaining, closed loop ECLSS system yet, and there won't be for a while. Even if we get that, and everything else required to go to either Venus or Mars and settle humans on either of them permanently, why would you choose Venus over Mars? Venus is worse for settling humans on in every conceivable way, most notably the fact that we're talking about a ridiculous city in the clouds. You can plant both feet firmly on Martian soil just to name one advantage over Venus.

[Findthepin1]

Well, most of the heat is due to the greenhouse effect from the atmosphere, not proximity to the sun.

It's the same on Venus as it is on Earth. The 86.5 atm of CO2 partial pressure is creating a greenhouse effect, but if Venus were further from the sun it would be correspondingly colder. It only amplifies what's already there. Also, the CO2 in the atmosphere is only a weak greenhouse gas relative to the sulphuric compounds in the clouds, but creates the vast majority of the heating because of its sheer mass. 90 atm of oxygen would probably heat the planet up almost as much. At these pressures, it's not so much of a greenhouse effect as a "photon-saying-oh-my-god-i-can't-get-out-i'm-surrounded" effect.

Venus gets its heat from the sun as do all other inner planets in this system. The atmosphere and greenhouse effect only serve to hold it there for longer.

Edited May 17, 2015 by Findthepin1

[K^2]

Yes but on the flipside, if you handwave practical, economical and political hurdles why not just build an interstellar warp drive and go find an Earth twin that is better than Earth in every single way and relocate the entire population of Earth there?

We're not hand-waving it away. We're prioritizing based on it. I don't think we can build it this century. But it's definitely an achievable goal given technology that already exists and applications we can reasonably expect. Which means that this century, and even within the upcoming decades, it'd be worth testing it out. Deploying a station and trying to send a manned expe

There is no self-sustaining, closed loop ECLSS system yet, and there won't be for a while.

Look around. You're living in one. Life support is a problem of scale. Make it big enough, plant some trees, and it takes care of itself.

Even if we get that, and everything else required to go to either Venus or Mars and settle humans on either of them permanently, why would you choose Venus over Mars? Venus is worse for settling humans on in every conceivable way, most notably the fact that we're talking about a ridiculous city in the clouds. You can plant both feet firmly on Martian soil just to name one advantage over Venus.

Mars is absolutely horrible place for a colony. First, you have to build pressurized domes. On Venus, ambient pressure would match pressure in the habitat, so the panels would only have to stand up to wind. If one of these happens to blow out... you just need to go to a different room. If you happened to end up cut off and have to go through area exposed to the atmosphere... you just need to hold your breath. Well, and take the shower ASAP once you get inside. On Mars, ambient pressure will require you to fully exhale, causing oxygen to evaporate out of your blood into your lungs, bringing useful consciousness to bellow 15 seconds. Good luck saving your rear in case your dome becomes depressurized. And these things are much more likely to happen on Mars, since besides significant stress due to pressure differential, your entire structure is sand-blasted on regular basis.

And that's just problems with the habitat. Construction materials on Mars are going to be even more scarce. You'd probably opt for ceramics and silicon over carbon there, since atmosphere is so thin. But key component for just about anything is water, which is going to be super scarce on Mars. Yeah, there are decent supplies of it in a few places. Enough to run an outpost. But you try to build a colony there, and they'll have serious shortages within decades if not years. You'll have to run water mines all over the planet just to supply your cities.

Finally, the elephant in the room. Gravity. I lean towards Mars gravity being strong enough to prevent lethal side-effects if the personnel follows strict exercise regimen. But life at a little over a third of Earth gravity is not going to be peaches. It will require daily exercise routine for absolutely everyone in the colony just to keep their hearts pumping and the bones from braking. How well the young and elderly will take it? Well, it's hard to tell. Nobody experimented on it sufficiently. But it's very likely that at best, life expectancy on Mars is not going to be what it is on Earth.

And then we have Venus. At an altitude of approximately 60 km, ambient temperatures of about 70°F, the pressure is about 0.5bar, requiring a slightly oxygen-rich environment, but not to the point of being a fire hazard.. Gravity is 90% of Earth normal, and so it causes no serious side-effects. The colony is located above the bulk of the clouds, but still bellow significant number of the sulfuric acid clouds. Note that the later present little danger, since concentration is pretty low at these altitudes. The weather is mostly overcast, but could range from foggy to almost clear. Basically, if you grew up in London, you'll feel right at home.

The only planet in this star system with better environment for human colony is Earth. That is simply not even a question.

That's not to say that Mars should be overlooked. There are some fantastic mining opportunities on Mars. Mars is easy to launch from, so I expect it to be an important industrial location. That would necessitate constant human presence there. People living with their families. But it would come with hardships outlined above, and I don't expect anyone to start a family on Mars nor to retire there. It's a place you move to for a few years to help build your career in industry or mining. And then you move to the off-world offices on some orbital installation. And then you can retire on a ridiculous cloud city on Venus.