NASA Has Explored Manned Missions To Venus (newsweek.com)

NASA recently developed a program for manned missions to explore Venus -- even though the planet's surface is 860 degrees, which NASA explains is "hot enough to melt lead." Long-time Slashdot reader Zorro shares this week's article from Newsweek: As surprising as it may seem, the upper atmosphere of Venus is the most Earth-like location in the solar system. Between altitudes of 30 miles and 40 miles, the pressure and temperature can be compared to regions of the Earth's lower atmosphere. The atmospheric pressure in the Venusian atmosphere at 34 miles is about half that of the pressure at sea level on Earth. In fact you would be fine without a pressure suit, as this is roughly equivalent to the air pressure you would encounter at the summit of Mount Kilimanjaro.

Nor would you need to insulate yourself as the temperature here ranges between 68 degrees Fahrenheit and 86 degrees Fahrenheit. The atmosphere above this altitude is also dense enough to protect astronauts from ionising radiation from space. The closer proximity of the sun provides an even greater abundance of available solar radiation than on Earth, which can be used to generate power (approximately 1.4 times greater).... [C]onceivably you could go for a walk on a platform outside the airship, carrying only your air supply and wearing a chemical hazard suit.
Venus is 8 million miles closer to Earth than Mars (though it's 100 times further away than the moon). But the atmosphere around Venus contains traces of sulphuric acid (responsible for its dense clouds), so the vessel would need to be corrosion-resistant material like teflon. (One NASA paper explored the possibility of airbone microbes living in Venus's atmosphere.) There's a slick video from NASA's Langley Research Center titled "A way to explore Venus" showcasing HAVOC -- "High Altitude Venus Operational Concept."

"A recent internal NASA study...led to the development of an evolutionary program for the exploration of Venus," explains the project's page at NASA.gov, "with focus on the mission architecture and vehicle concept for a 30 day crewed mission into Venus's atmosphere." NASA describes the project as "no longer active," though adding that manned missions to the atmosphere of Venus are possible "with advances in technology and further refinement of the concept."

Comments

Waste of resources...

[sarren1901]

We are better off sending drones and satellites with science labs already onboard. This does sound better then a manned mission to Mars though. Being able to build a space craft or space station in the atmosphere of Venus sounds incredible and a whole lot more practical then going to Mars.

Both seem like overly expensive, resource intensive activities that we would be better off sending more drones.

Re:Waste of resources...

[ShanghaiBill]

The drones could build a cloud city like Lando Calrissian administered above Bespin.

Once the city is completed, humans could colonize it and begin terraforming Venus from the cloud tops downward.

This makes way more sense than a Mars colony. Those Mars nutters need to get a grip on reality.

Seriously?

[CaptainDork]

As surprising as it may seem, the upper atmosphere of Venus is the most Earth-like location in the solar system.

Earth is even more Earth-like. I say Venus may be the second most Earth-like location in the solar system.

Re:Seriously?

[Anonymous Coward]

Well, if we don't do something about CO2 emissions, then Earth will become more Venus like in the future...

Fahrenheit on Venus?

[zmooc]

Nor would you need to insulate yourself as the temperature here ranges between 68 degrees Fahrenheit and 86 degrees Fahrenheit (...)

I highly doubt that; temperatures in the Fahrenheit-range are found only in a handful of territories on Venus' planetary neighbor.

Not TV friendly

[Tim the Gecko]

Basement: Can't see anything outside; able to study radar images and scientific data transmitted from Venus probe; can go outside if necessary; cheap.

Manned Venus mission: Can't see anything outside; able to study radar images; able to go outside to stand in corrosive acid cloud (assuming you wear the right suit); super-expensive.

Re:Not TV friendly

[Rei]

So, what you can see depends on the design approach. I'm not a big fan of the HAVOC approach, where people live in a little capsule under the lift envelope; the Landis approach, where people live and farm in the (huge) lift envelope itself makes far more sense. Therein you have a vast, bright open space full of life and where you can live basically wherever you want; the lowest-mass option for crew quarters is just large tents hanging from catenaries (non-rigid) or the frame (rigid). Don't get along with someone? Move half a kilometer away from them, to the opposite side of the habitat.

What you see outside: With the possible exception of the polar vortices, you never see either the ground or the sun. You have a brightness gradient, where above you is somewhat brighter than below you. You do pass through convective weather systems however that are surprisingly similar to those in Earth's troposphere. We don't know at this point whether there's any precipitation or frosts in these (that's how pathetically little we know about Venus : The data from the Vega balloons has alternately been argued to confirm or deny precipitation and/or frosts), but as far as what you'd see, these clouds would be visible, albeit in relatively low contrast.

As for stepping outside: barring precipitation (which, as mentioned, we don't know whether it actually exists), the outside environment isn't like a sulfuric acid bath. It's several to several dozen mg/m^3 of sulfuric acid mists. By contrast, OSHA allows people to breathe up to 1 mg/m^3 for an entire 8-hour shift. Now, the acid concentration on Venus is higher than it would be on Earth (H2SO4 is highly hygroscopic and absorbs moisture from the air to self-dilute), but the key takeaway is, the environment is more like a very bad smog (or more accurately, vog). The H2SO4 is far more of a resource than a hazard, and it would actually be convenient if it were more common (heating first drives off free H2O; further heating decomposes H2SO4 to SO3 + H2O; and further heating of SO3 over a vanadium oxide catalyst decomposes it to SO2 and O2; contrarily, SO3 can be reused in the gas scrubber as a nucleating agent to help capture free H2O after doing an initial electrostatic and/or ionic liquid scrubbing of the H2SO4 mists).

Studies don't matter

[Kjella]

NASA has probably "explored" interstellar flight too, it doesn't mean it's anywhere near ready to go. Right now the US can't even send people to the ISS. Of course hand-waving is sometimes useful like "if we ignore all the problems of getting to Mars, what's the problems we have on Mars" but you got to take that into account. Sure at the right altitude Venus orbit is relatively human friendly. It doesn't mean we have the means to get people from Earth to there or back again. And we'd probably have to build the ship much more protected for the crew to survive the trip, so it would just be to go outside in order to go outside. Unlike Mars, where we could actually do something outside the ship.

Do a robotic mission.

[WindBourne]

Automated Submarine/balloon would make sense for doing a mission.

Venus colonies

[XXongo]

This has been talked about several times, for example, "Why We Should Build Cloud Cities on Venus," here: https://motherboard.vice.com/en_us/article/539jj5/why-we-should-build-cloud-cities-on-venus
based on this 2003 paper: https://ntrs.nasa.gov/archive/nasa/casi.ntrs.nasa.gov/20030022668.pdf

Yes, seriously

[Geoffrey.landis]

" I say Venus may be the second most Earth-like location in the solar system." Well, that's bullshit.

No, at the right altitude-- about 56 km above the surface-- Venus is remarkably Earthlike.

No oxygen, of course, but in temperature and pressure, very close.

I wrote a paper about this: "Colonization of Venus", back in 2003. Glad to see my work is being taken seriously!

Re:Yes, seriously

[Rei]

Nice to see you back, Geoffrey :) Keep up the great work!

I am curious what you think of the early-phase HAVOC approach, of having the crew slung underneath a lift envelope rather than living inside it. I have to admit, I'm not a fan (I also found some of their mass budget numbers in the initial proposal rather questionable). But it's still nice to see some work being done towards any Venus habitation concepts. :)

I guess on the upside they can be freed from the need for a transparent envelope, and thus use, say vectran or similar. Liquid crystal polymers have such nice properties for an environment like Venus. But there's still great options for (layered) transparent envelopes. When analyzing possibilities it looked like optimal layers would be along the lines of a PCTFE outer layer, an EVOH or PVDC gas barrier layer, a potential fluoropolymer coating for antifouling / anticondensation properties, and CF reinforcement, if sustainability is taken into account (PCTFE minimizes the amount of F required, since it's only found in lower ppb quantities and can be melt-bonded with other layers; it's also extremely resistant to water permeation); EVOH is simpler to produce than the more commonly considered PET and also opens up a production path for adhesives. PVDC also looks attractive, at the cost of requiring more chlorine, which isn't in huge abundance (although certainly more abundant than fluorine). As for reinforcing fibres, CF is harder to produce than UHMWPE, but its low creep, UV resistance, and wettability probably makes this worth it.

For our sample habitat, with an envelope fabric comprised of 20um PCTFE, 70um PVDC, and another 10um PCTFE, that worked out to 183g/m (not counting reinforcement) and had the following daily permeation rates w/continuous atmospheric scrubbing:

H2O: -1.44 kg
O2: -0.29 kg
N2: -0.22 kg
HF: 2.91 ppb
H2S: 19.1 ppb
HCl: 23.3 ppb
H2SO4: 294 ppb
SO2: 92.7 ppm
CO: 98.8 ppm
CO2: 11.9 kg

Looks like that would (naively) require interior air scrubbing around 15 times per day to avoid reaching gas levels which would be harmful to agriculture. But probably not that bad in practice, as problematic gases like HF are hygroscopic and would be prone to being absorbed into condensation films and hydroponics channels, and with such tiny permeation rates, it might be worth considering just neutralizing them in the envelope itself. If the minor species can be dealt with, the bulk CO2 only requires about 1% of the envelope be scrubbed daily to maintain comfortable levels (and that's assuming no plant uptake). Oxygen and nitrogen losses are trivial, although the water losses are annoyingly high, even with the use of PCTFE; still, the losses are only about 5% of the water recovery rates we calculated for our scrubber.

This is sort of a long-winded way of saying... a transparent envelope like your '93 paper called for looks perfectly workable, and sustainable. :)

Re:Yes, seriously

[Rei]

Oh yeah, I'm curious as to what your thoughts on sustainable ascent stages are. The early stages of HAVOC call for what's basically a gigantic Pegasus rocket... anything but sustainable, of course.

Sustainable chemical ascent vehicles look possible, but are... annoying. It basically requires two stages, which you have to recover with balloons, and re-mate while they're hanging under your habitat, and the propellant to re-fill them requires the vast majority of your habitat's lift capacity. You're also limited to low-hydrogen fuels like carbon monoxide, acetylene or cyanogen, generally meaning some combination of poor performing or hot burning (cyanogen with a small fraction of methane or hydrogen mixed in looked best in terms of balancing performance, temperature, and hydrogen content). It's... workable, but not pretty.

Nuclear thermal looked way better. You're stuck burning pure hydrogen, but don't actually need that much of it. And some nuclear thermal designs that incorporate compressors offer the potential to hover, allowing one to ditch balloon recovery. It's single stage, and allows for a significantly lower wet mass than a chemical ascent vehicle.

Have you investigated sustainable ascent stages much? What were your thoughts?

Re:Yes, seriously

[Rei]

There's much more detail about surface access and resources in much more detail in Chapter 8 here. Contrary to your assertion, Venus has all of the signs for heavy differentiation, both theoretical and observed: abnormally large melts, abnormally low viscosities, abnormally long cooling times, repeated remelting, structures associated with secondary differentiation on Earth (such as rhyolite domes, which are the most likely explanation for Venus's pancake domes), etc. Venera 8 and 13 measured U, Th and K levels that were so enriched over what's normally found in basalt that Venera 8 was initially thought to have sampled granite instead. Venus also shows signs of potential widespread carbonatite volcanism, which on Earth form some of the most valuable ores for a number of elements. Venus also has its own unique ore-forming processes, to the point that the planet literally vaporizes and plates out metals and/or semiconductors in the form of high-altitude frosts. Venus has no liquid water to assist in forming ores, but its dense, acidic atmosphere provides it with unique ore-forming properties not found anywhere else in the solar system.

In some ways, Venus is a natural refinery, separating out different compounds into layers - there are three separate cloud decks (with a virga underlying the lowest). For example the dominant species in the upper two cloud layers is sulfuric acid, the most likely dominant species in the lower cloud layer (or at least a major species) is phosphoric. Even metals appear to be found in Venus's upper atmosphere - for example, iron has been detected, most likely in the form of iron chloride. There are some metals that we don't even know what's happened to them - for example, our models show that mercury should be common in Venus's atmosphere, yet it hasn't been detected at all; we have no clue what's happened to it.

And as for "how to harvest" materials from the surface, the simplest method is one that we can't do effectively on Earth or Mars: dredging. Venus's atmosphere is dense enough that one could dredge fines using the same fan that the lander uses for propulsion. And as for the ability to land on Venus's surface, come on - that was achieved with 1960s/1970s Soviet technology. Yes, we're talking more complex systems, but nothing remotely beyond our reach.

Re:Good luck with that

[Rei]

I think that's sort of the point - so long as people see Venus as "uninhabitable", it'll keep being robbed of funding for robotic missions, as it has been for the past several decades. Having a manned program for Venus - even if manned missions are, for all practical purposes, decades off - has the potential to help get more funding for exploring the planet.

Terraform Venus!

[Grog6]

Use several large asteroids, then some smaller ones...

Step 1: Blow of 90% of the atmosphere with a large heavy asteroid.
You could also tip the planet a bit, and add some spin.

Step 2: Hit it with another asteroid heavy enough to penetrate the planet, spinning the core to create a magnetic field to protect Immigrants from Earth.

Step 3: Hit it with slower moving asteroids built up of various frozen gasses and water, until there are global oceans.

Step 4: Wait for it to cool off a bit, after the Re-engineering step.
Profit!

This is what we should be planning; deorbiting things to the inner solar system is easy if you don't need to slow down at the end. :)

I wonder if I can get funding...

Re:Melt lead.

[Zumbs]

Many countries and regions use comma for the decimal point.

Wikipedia has a nice overview. But this is an English writing site and English uses a dot as decimal separator.

Hmmm

[Hognoxious]

you could go for a walk on a platform outside the airship, carrying only your air supply and wearing a chemical hazard suit.

Shiiiit!

What?

I dropped the keys!

Sure

[MerlinTheWizard]

We haven't messed enough of the universe yet. There's no reason earth should be our only trash can! :D

I hope it's a Night Flight to Venus

[Lynchenstein]

Gawd I'm old.