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#151 2015-02-06 15:45:35

Terraformer
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From: The Fortunate Isles
Registered: 2007-08-27
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Re: Mission to Venus

Why go to Venus?

Why *not* go to Venus?

The same arguments could be said about colonising... well, anywhere. Why not just mine the materials and send them back home? Maybe because people are moving there to live, rather than to make a bunch of shares mining, and so will go as long as there are the resources to support them.


Use what is abundant and build to last

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#152 2015-02-06 21:24:15

Void
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Registered: 2011-12-29
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Re: Mission to Venus

I think that any effort needs to keep an eye on being of service to the human race.  If possible.  That does not prohibit side ventures.  Reality might, but not that.

I think I see a potential progression that makes sense to me at least, but before I go to that, some comments about Venus.

As I see it either you focus on Terraforming Venus, or you focus on inhabiting it.  I have not seen any suggestions about terraforming Venus that will not take a long time, and that will pay the bills while the terraforming is being done.  So for me inhabiting Venus is the major option for something that might pay it's own way, and be a contribution to our so called future civilization.

Just jumping into the clouds requires hardware, lots of it, and the clouds are unfriendly to both Humans and Machines at this time.  Getting the materials means donations from other rocky objects in orbit of the sun, and the cloud people it seems to me will have little ability to pay for those materials.  So, I think that ultimately the answer is to use machines to build a civilization from the surface up, where eventually machines on the surface provide materials to the clouds, and of course I want to get rid of the acid nature of the clouds.  Machines on the surface will have to be very tolerant and adapted to the conditions.  To progress to the ability to create those machines I call on a progression.

Several entities such as Nasa and SpaceX seem to be aimed at Mars as a preferred goal.  I think that given time, and a continuation of a technological branch of humanity, they will settle Mars.  I think that during that effort the Moon will also be accessed as a spill over effect.

Those two environments will give lessons on how to deal with the asteroid belt and Mercury.

If humans ever settle Mercury it looks as though they might prefer to start by settling at the poles.  But most of the other planet has a very hot environment during the day, and lunar cold at night. (More or less)

They should be able to travel about during the night or twilight, and do constructions, and maintenance on machines.
But I expect that they could eventually build robots with "Stirling Engines" which would have a lot of on board power during the day.  I could be wrong, but I would think that a solar heat collector could be on top, and a infrared deflector on their bottoms.  In between, I am supposing (I hope I am correct), that due to the vacuum, they could radiate heat to the non solar sky.  So, mobile equipment with a very large temperature span to power them.  Such machines may be able to have protected cooled parts, but will also have parts that will have to tolerate the very high heat.  That will be useful technology for eventually attempting to work in the surface heat of Venus.

I was happy to see that there are those who actually have plans for further probes to work in the surface environment of Venus, but still, I think the progression will be a good way to get there.

In the meantime, I would like to think that if ions can be harvested from the tail of Venus, then that could be traded for metals from elsewhere, and so long before an attempt to inhabit the clouds of Venus occurred, a community of people would already live in the orbit of Venus.

So with all that a great deal of support would be available to do whatever it is they might do with Venus.

This thread began with an article about dumping some people in lighter than air ships into the atmosphere of Venus.  They would take a return rocket with them.  I don't see what they could do that machines could not.

Rather, I guess I could justify it if it were a proof of technology mission.  But before doing that I would think that efforts would be made to make simulation chambers on Earth, and to expose materials and models to that simulated environment.  If they proved the technology, then perhaps an actual test.  But before a actual human test, I would think you would do it at least one time without people.  That is enter the atmosphere, and deploy, and do an endurance test, and see if you could get the return vehicle to get back to orbit OK.

That would be a lot of effort that could be expended on easier targets instead, with better pay back, as I think others have suggested.

Last edited by Void (2015-02-06 21:37:30)


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#153 2015-02-07 15:53:52

JCO
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Registered: 2015-01-22
Posts: 35

Re: Mission to Venus

I think floating craft in the Venus atmosphere is a good logical next step. I fully agree that this is something that must involve robotic missions well before we hope to send people. It should be fairly simple to send a probe there with a supply of liquid nitrogen that would be used to inflate a balloon after atmospheric entry. It would also be a procedure that was easier to test before launch as it would be all but identical to having a vehicle reentering Earth's atmosphere inflating a helium balloon before touch down. Unlike landing on the Moon or Mars we have an almost perfect analog environment for testing.

Lifting body drones could be used to 'orbit' Venus within its atmosphere and provide an exceptionally detailed radar mapping of Venus's surface. The main probe would provide an opportunity to for the first time study in detail the meteorology of another planet.

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#154 2015-08-23 22:30:13

SpaceNut
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Re: Mission to Venus

I reminded of this topic: so copying your post to here,,,

Tom Kalbfus wrote:

Also remember half of the Sun's disk would be below the horizon at all times as the disk of the Sun slowly moves eastward along the horizon, it might even be cooler at the 55 km altitude at 1 atmosphere of pressure. I think the Sun would appear rather red as it does along our horizon. If the balloon is not tethered, it could use propellers to move away from the Sun, and thus make it appear to set, so there could be night, then it would turn around and head back towards the Sun for a Sunrise, that way we could have a normal 24-hour diurnal cycle. Maybe that's worth considering.
12OLVenusf4-nohed2-1418403309445.jpg
Doesn't say how fast these things move. I wonder how fast this airship would have to move to get the entire disk of the Sun below the horizon?
24342BD100000578-0-image-a-17_1419182793965.jpg
These folks may have to be couch potatoes. I wonder if they could have exercise equipment behind those chairs. I think a treadmill would be nice, they'd need a lavatory, and maybe a small kitchen in the back. Also when they flushed the toilet, where do you suppose the water would go? Probably get recycled I imagine, if the equipment to do that wasn't too heavy. The engines that propel the airship would be electrical, they would probably hear a whirr sort of like a giant fan. Do you think there would be handholds along the sides of the airships so astronauts can climb to the top of the gas bag in protective suits? If the airship climbs high enough, they can get a good view of the stars at night, as there never is a Moon to drown them out. Maybe they can set up a telescope on the top and look at the Earth.

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#155 2015-08-24 10:29:52

Tom Kalbfus
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Registered: 2006-08-16
Posts: 4,401

Re: Mission to Venus

SpaceNut wrote:

I reminded of this topic: so copying your post to here,,,

Tom Kalbfus wrote:

Also remember half of the Sun's disk would be below the horizon at all times as the disk of the Sun slowly moves eastward along the horizon, it might even be cooler at the 55 km altitude at 1 atmosphere of pressure. I think the Sun would appear rather red as it does along our horizon. If the balloon is not tethered, it could use propellers to move away from the Sun, and thus make it appear to set, so there could be night, then it would turn around and head back towards the Sun for a Sunrise, that way we could have a normal 24-hour diurnal cycle. Maybe that's worth considering.
http://cdn.zmescience.com/wp-content/up … 309445.jpg
Doesn't say how fast these things move. I wonder how fast this airship would have to move to get the entire disk of the Sun below the horizon?
http://i.dailymail.co.uk/i/pix/2014/12/ … 793965.jpg
These folks may have to be couch potatoes. I wonder if they could have exercise equipment behind those chairs. I think a treadmill would be nice, they'd need a lavatory, and maybe a small kitchen in the back. Also when they flushed the toilet, where do you suppose the water would go? Probably get recycled I imagine, if the equipment to do that wasn't too heavy. The engines that propel the airship would be electrical, they would probably hear a whirr sort of like a giant fan. Do you think there would be handholds along the sides of the airships so astronauts can climb to the top of the gas bag in protective suits? If the airship climbs high enough, they can get a good view of the stars at night, as there never is a Moon to drown them out. Maybe they can set up a telescope on the top and look at the Earth.

Just one thing, why does NASA propose using helium tanks? Wouldn't hydrogen tanks weigh half as much? so instead of 8183 kg of helium you bring 4091.5 kg of hydrogen, as hydrogen doesn't burn in Venus' atmosphere, you don't get a "Hindenburg effect." Same pressure, half the weight, twice the lift. You can pack an additional 4091.5 kg of hydrogen, and another thing you could do is turn that into 20,457.5 liters of water using Venusian oxygen obtained from carbon dioxide. Also you can collect sulfuric acid from the clouds separate out they hydrogen, and you can replenish the hydrogen that leaks out of the gas bag, you can't obtain helium nearly as easily on Venus. Helium is only used because it is inflammable in Earth's atmosphere, but that's not a problem with Venus.

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#156 2015-08-24 11:38:53

Antius
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From: Cumbria, UK
Registered: 2007-05-22
Posts: 1,003

Re: Mission to Venus

Void wrote:

I think that any effort needs to keep an eye on being of service to the human race.  If possible.  That does not prohibit side ventures.  Reality might, but not that.

I think I see a potential progression that makes sense to me at least, but before I go to that, some comments about Venus.

As I see it either you focus on Terraforming Venus, or you focus on inhabiting it.  I have not seen any suggestions about terraforming Venus that will not take a long time, and that will pay the bills while the terraforming is being done.  So for me inhabiting Venus is the major option for something that might pay it's own way, and be a contribution to our so called future civilization.

Just jumping into the clouds requires hardware, lots of it, and the clouds are unfriendly to both Humans and Machines at this time.  Getting the materials means donations from other rocky objects in orbit of the sun, and the cloud people it seems to me will have little ability to pay for those materials.  So, I think that ultimately the answer is to use machines to build a civilization from the surface up, where eventually machines on the surface provide materials to the clouds, and of course I want to get rid of the acid nature of the clouds.  Machines on the surface will have to be very tolerant and adapted to the conditions.  To progress to the ability to create those machines I call on a progression.

I am extremely doubtful of the practicality of actually colonising Venus using 'cloud cities'.  The problem is that the static lift provided by an air filled balloon is inherently limited and would not appear to be enough to lift the mass budget for an entire new civilisation.

At 55km, the pressure on Venus is 1.066bar and temperature is 27C.  Under those conditions, the density of CO2 is 1.9kg/m2 and the density of air is 1.2kg/m3.  That means that each cubic metre of air filled habitat will provide 0.7kg of static lift.

Let us consider an example habitat that is 100mx100mx100m.  The total lift would be 700 tonnes.  That lift needs to be sufficient for the structure, internal living space and subdivisions, the people, food and water, life support, plants, scientific equipment, etc.

I can see that being workable for a limited short term base, but consider the sheer amount of equipment you need to actually start a new civilisation on a new planet.  Equipment is needed for ore processing, manufacturing practically everything, growing your own food, recycling wastes, generating power.  That is some serious equipment.  And it is seriously heavy and bulky.  On Mars, we can at least stockpile it on the surface.  If it ends up weighing tens of thousands of tonnes, it’s a problem for delivery but not really a problem when it’s there.  Do we really think we can suspend that sort of thing from a balloon with all the limitations on mass budget that it suffers from?

And then we have the difficulties of trying to expand the settlement.  Do we need to mine the Venusian surface for metals and other materials?  How would that be done and how can we transport it back to a cloud city?  How do transport people and materials between a cloud city and Venus orbit?  Do we need to land a rocket on our balloon?

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#157 2015-08-24 12:37:30

RobertDyck
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From: Winnipeg, Canada
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Re: Mission to Venus

Tom Kalbfus wrote:

why does NASA propose using helium tanks? Wouldn't hydrogen tanks weigh half as much?

Density of liquid helium at boiling temperature is 0.125 grams per cm^3 or 125 kg/m^3. Density of liquid hydrogen is 70.85 kg/m^3. So LH2 requires a much bigger tank. Mass of tank is a concern. And helium boils at −269°C (4.15°K) at 1 atmosphere pressure, while hydrogen boils at −252.87°C (20.28°K). Hmm, temperature for boil-off would suggest hydrogen is better.

The other issue is containment. Hydrogen tends to flow right through most materials. Metal tanks are used for hydrogen because it leaks right through the walls of composite tanks. Years ago I did suggest a composite tank for hydrogen: aluminized Mylar bladder within a fibreglass tank. The fibreglass would hold pressure, but the aluminum would stop leakage. That means metal still stops hydrogen, just a very thin layer. Actually, this design would still leak a little, but leakage would be comparable to evaporation of gasoline from a car's fuel tank. So it could be used for hydrogen fuel cell cars. And Mylar remains strong in winter temperatures in Alaska. Since I posted this on a public internet forum, some manufacturers are looking at making it. And the Hindenburg actually used something similar, although more primitive. Hindenburg used fabric painted with a sticky dope coating mixed with powdered aluminum and powdered iron oxide. Similar idea: use metal to contain hydrogen. But modern aluminized Mylar doesn't leave gaps between powder particles. However, if you want to use it on Venus, you would want it to last months. How much leakage for hydrogen vs helium?

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#158 2015-08-24 18:44:47

Terraformer
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From: The Fortunate Isles
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Re: Mission to Venus

I'm fairly sure that helium leaks far more than hydrogen, due to the smaller size of the helium particles.

But the best lifting gas for Venus is probably nitrogen, since it can be extracted fairly easily from the atmosphere.


Use what is abundant and build to last

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#159 2015-08-24 20:13:15

Tom Kalbfus
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Registered: 2006-08-16
Posts: 4,401

Re: Mission to Venus

RobertDyck wrote:
Tom Kalbfus wrote:

why does NASA propose using helium tanks? Wouldn't hydrogen tanks weigh half as much?

Density of liquid helium at boiling temperature is 0.125 grams per cm^3 or 125 kg/m^3. Density of liquid hydrogen is 70.85 kg/m^3. So LH2 requires a much bigger tank. Mass of tank is a concern. And helium boils at −269°C (4.15°K) at 1 atmosphere pressure, while hydrogen boils at −252.87°C (20.28°K). Hmm, temperature for boil-off would suggest hydrogen is better.

The other issue is containment. Hydrogen tends to flow right through most materials. Metal tanks are used for hydrogen because it leaks right through the walls of composite tanks. Years ago I did suggest a composite tank for hydrogen: aluminized Mylar bladder within a fibreglass tank. The fibreglass would hold pressure, but the aluminum would stop leakage. That means metal still stops hydrogen, just a very thin layer. Actually, this design would still leak a little, but leakage would be comparable to evaporation of gasoline from a car's fuel tank. So it could be used for hydrogen fuel cell cars. And Mylar remains strong in winter temperatures in Alaska. Since I posted this on a public internet forum, some manufacturers are looking at making it. And the Hindenburg actually used something similar, although more primitive. Hindenburg used fabric painted with a sticky dope coating mixed with powdered aluminum and powdered iron oxide. Similar idea: use metal to contain hydrogen. But modern aluminized Mylar doesn't leave gaps between powder particles. However, if you want to use it on Venus, you would want it to last months. How much leakage for hydrogen vs helium?

The other side of the coin is where would you get more helium on Venus, as I understand it, the atmosphere of Venus contains very little helium, but there is hydrogen in sulfuric acid droplets, and besides the colonists will need water. Oxygen is plentiful in carbon-dioxide, and hydrogen can be found in the sulfuric acid clouds, some of the hydrogen can be used as a lifting gas while the rest can be used to make water. If your going to use helium, your going to have to keep importing more of that gas from Earth, as I don't know how you would get it from Venus.

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#160 2015-08-24 21:00:19

RobertDyck
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From: Winnipeg, Canada
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Re: Mission to Venus

Tom Kalbfus wrote:

The other side of the coin is where would you get more helium on Venus, as I understand it, the atmosphere of Venus contains very little helium, but there is hydrogen in sulfuric acid droplets, and besides the colonists will need water. Oxygen is plentiful in carbon-dioxide, and hydrogen can be found in the sulfuric acid clouds, some of the hydrogen can be used as a lifting gas while the rest can be used to make water. If your going to use helium, your going to have to keep importing more of that gas from Earth, as I don't know how you would get it from Venus.

All very valid points. In fact, most of the clouds of Venus are water clouds. There is sulphuric acid (I use the Canada/UK spelling), but most of the water is just water. So you can condense moisture from the clouds of Venus, filter that, use electrolysis to get hydrogen.

But NASA doesn't think in terms of permanent settlement. They think in terms of exploration. And NASA hasn't embraced ISRU. Some in NASA like to talk about ISRU, but no mission planner is willing to even consider it.

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#161 2015-08-24 22:23:11

Void
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Registered: 2011-12-29
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Re: Mission to Venus

Helium
http://www.ncbi.nlm.nih.gov/pubmed/17831413

Helium is removed at an average rate of 10(6) atoms per square centimeter per second from Venus's atmosphere by the solar wind following ionization above the plasmapause. The surface source of helium-4 on Venus is similar to that on Earth, suggesting comparable abundances of crustal uranium and thorium.

Could you drill wells for it?  Harsh environment for that, so I suppose you might extract it from the atmosphere, which would be expensive.  I really didn't think that floating habitats were going to rely on Helium anyway, Air gasses, such as N2 more or less?  But if you could have helium bubbles inside of your main N2 bubbles, perhaps it could be worth it, and you might be able to recover Helium spills, because they would still be contained in the N2 bubble.

But then again that offers a solution for H2 leaking through it's containers.  If H2 bubbles were inside of a main N2 bubble, then I would think a centrifuge might allow you to recover much of the H2 leaking into the N2 bubble, and recycle it back into the H2 bubbles before it leaked through the N2 bubble wall.  Plus the barrier between the CO2 atmosphere and H2 bubbles provided by the N2 would be an extra safety margin, even though it is rather hard to ignite a fire of H2 and CO2.

Last edited by Void (2015-08-24 22:26:48)


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#162 2015-08-25 01:00:12

Tom Kalbfus
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Posts: 4,401

Re: Mission to Venus

RobertDyck wrote:
Tom Kalbfus wrote:

The other side of the coin is where would you get more helium on Venus, as I understand it, the atmosphere of Venus contains very little helium, but there is hydrogen in sulfuric acid droplets, and besides the colonists will need water. Oxygen is plentiful in carbon-dioxide, and hydrogen can be found in the sulfuric acid clouds, some of the hydrogen can be used as a lifting gas while the rest can be used to make water. If your going to use helium, your going to have to keep importing more of that gas from Earth, as I don't know how you would get it from Venus.

All very valid points. In fact, most of the clouds of Venus are water clouds. There is sulphuric acid (I use the Canada/UK spelling), but most of the water is just water. So you can condense moisture from the clouds of Venus, filter that, use electrolysis to get hydrogen.

But NASA doesn't think in terms of permanent settlement. They think in terms of exploration. And NASA hasn't embraced ISRU. Some in NASA like to talk about ISRU, but no mission planner is willing to even consider it.

Well I'm sure NASA has a bottomless budget and is quite willing to supply the Helium to anyone that needs it for as long as it takes!

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#163 2015-08-25 20:45:01

SpaceNut
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From: New Hampshire
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Posts: 29,433

Re: Mission to Venus

The hydrogen in close proximity to the oxygen that the crew breats would represent a risk that might be to great even when weighing in that the materials are harder to keep it from escaping, So I would still want to use helium as the lifting gas as it has a much lower risk to crew.

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#164 2015-08-25 21:07:11

SpaceNut
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From: New Hampshire
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Posts: 29,433

Re: Mission to Venus

Void wrote:

In my opinion that divides into two different objectives. 
1) Scouting mission.
2) Habitation mission.

1) For the scouting mission, I have to wonder why people would be placed into the atmosphere at all.  It is dangerous, and I don't see that there is much that could be accomplished that could not be done with machines.

From my point of view, retrieval could involve having an orbital device come down rather deep so that it could glide/hover slow, and have the humans similarly get into a powered aircraft, and connect with it.  Very hard to do, and very dangerous.

2) For habitation, there are two options, (And a hybrid of them).
     a) Drop significant tonnage into the atmosphere and assemble it.
     b) Develop a robot presence on the surface and up into the clouds, and manufacture habitat there.

I would think that a multi-layered habitat which had a deck down at the 10 bar level, and decks above to a more habitable level, might allow for a glider to land at the 10 bar level onto an open deck.  Then that being brought back up to the highest deck level could be refueled, and launched to orbit.  But lots of danger there.  I think that it is a better plan that most people going to Venus plan to stay there for a long time, to reduce launches.

This could be modified, if a robot community made resources so abundant that rockets cost very little (Unlike now).

But this is all only my opinion, and can be justly challenged by other minds notions, and by new discoveries in the nature of things, or new technologies.

I see scouting missions as a proving ground for habitation and as a stepping stone to risk assessment for long term duration inhabiting using any and all insitu resources.

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#165 2015-08-25 21:08:33

Tom Kalbfus
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Re: Mission to Venus

SpaceNut wrote:

The hydrogen in close proximity to the oxygen that the crew breats would represent a risk that might be to great even when weighing in that the materials are harder to keep it from escaping, So I would still want to use helium as the lifting gas as it has a much lower risk to crew.

The hydrogen gas bag could be kept separate from the nitrogen-oxygen gas bag so hydrogen won't leak from the hydrogen gas bag to the nitrogen-oxygen gas bag. If hydrogen leaked it would leak into the carbon-dioxide atmosphere and diffuse within it. Think of a Dome of air within a gas bag hanging from cables underneath a hydrogen filled blimp with carbon-dioxide atmosphere in between. Hydrogen would tend to leak out into the carbon dioxide where it would not burn. The air pressure within the breathable air back would be higher that the atmosphere outside, so it would leak out while the carbon-dioxide would not leak in. Te airbag would have a floor bisecting it horizontally so the top part would make a dome, while the bottom part would be under the floor and unseen. One can put soil and trees in this habitat. Probably situated at one of the poles, the Sunlight would some in from the side ad ot be blocked by the blimp above.

Venus Weather Not Boring After All, NASA/International Study Shows 09.27.11
At first glance, a weather forecaster for Venus would have either a really easy or a really boring job, depending on your point of view. The climate on Venus is widely known to be unpleasant -- at the surface, the planet roasts at more than 800 degrees Fahrenheit under a suffocating blanket of sulfuric acid clouds and a crushing atmosphere more than 90 times the pressure of Earth's. Intrepid future explorers should abandon any hope for better days, however, because it won't change much.

591935main_venus-clouds-lgweb.jpg
Ultraviolet image of Venus' clouds as seen by the Pioneer Venus Orbiter (Feb. 26, 1979). Credit: NASA

"Any variability in the weather on Venus is noteworthy, because the planet has so many features to keep atmospheric conditions the same," says Dr. Tim Livengood, a researcher with the National Center for Earth and Space Science Education, Capitol Heights, Md., and now with the University of Maryland, College Park, Md.

"Earth has seasons because its rotation axis is tilted by about 23 degrees, which changes the intensity of sunlight and the length of the day in each hemisphere throughout the year. However, Venus has been tilted so much, it's almost completely upside down, leaving it with a net tilt of less than three degrees from the sun, so the seasonal effect is negligible," explains Livengood, who is stationed at NASA's Goddard Space Flight Center in Greenbelt, Md. "Also, its orbit is even more circular than Earth's, which prevents it from getting significantly hotter or cooler by moving closer to or further away from the sun. And while you might expect things to cool down at night -- especially since Venus rotates so slowly that its night lasts almost two Earth months -- the thick atmosphere and sulfuric acid clouds act like a blanket while winds move heat around, keeping temperatures pretty even. Finally, almost all the planet's water has escaped to space, so you don't get any storms or precipitation like on Earth where water evaporates and condenses as clouds."

However, higher up, the weather gets more interesting, according to a new study of old data by NASA and international scientists. The team detected strange things going on in data from telescopic observations of Venus in infrared light at about 68 miles (110 kilometers) above the planet's surface, in cold, clear air above the acid clouds, in two layers called the mesosphere and the thermosphere.

"Although the air over the polar regions in these upper atmospheric layers on Venus was colder than the air over the equator in most measurements, occasionally it appeared to be warmer," said Dr. Theodor Kostiuk of NASA Goddard. "In Earth's atmosphere, a circulation pattern called a 'Hadley cell' occurs when warm air rises over the equator and flows toward the poles, where it cools and sinks. Since the atmosphere is denser closer to the surface, the descending air gets compressed and warms the upper atmosphere over Earth's poles. We saw the opposite on Venus. In addition, although the surface temperature is fairly even, we've seen substantial changes – up to 54 degrees Fahrenheit (about 30 K change) – within a few Earth days in the mesosphere – thermosphere layers over low latitudes on Venus. The poles appeared to be more stable, but we still saw changes up to 27 degrees Fahrenheit (about 15 K change)."

591914main_polar-vortex-imageset.jpg
A set of images of the Venus south polar vortex in infrared light (at 3.8 microns) acquired by the Visible and Infrared Thermal Imaging Spectrometer instrument on ESA's Venus Express spacecraft. The images show the temperature of the cloud tops at about 65 km (40.4 miles) altitude. A darker region corresponds to higher temperature and thus lower altitude. The center of the vortex, at a temperature of about 250K (around minus 9.7 degrees Fahrenheit), is the deepest zone, exhibiting the highest temperature. Credit: ESA/VIRTIS/INAF-IASF/Obs. de Paris-LESIA

Kostiuk and Livengood are co-authors of a paper about these observations that appeared July 23 in the online edition of the journal Icarus.

"The mesosphere and thermosphere of Venus are dynamically active," said lead author Dr. Guido Sonnabend of the University of Cologne, Germany. "Wind patterns resulting from solar heating and east to west zonal winds compete, possibly resulting in altered local temperatures and their variability over time."

This upper atmospheric variability could have many possible causes, according to the team. Turbulence from global air currents at different altitudes flowing at more than 200 miles per hour in opposite directions could exchange hot air from below with cold air from above to force changes in the upper atmosphere. Also, giant vortexes swirl around each pole. They, too, could generate turbulence and change the pressure, causing the temperature to vary.

Since the atmospheric layers the team observed are above the cloud blanket, they may be affected by changes in sunlight intensity as day transitions to night, or as latitude increases toward the poles. These layers are high enough that they could even be affected by solar activity (the solar cycle), such as solar explosions called flares and eruptions of solar material called coronal mass ejections.

Changes were seen over periods spanning days, to weeks, to a decade. Temperatures measured in 1990-91 are warmer than in 2009. Measurements obtained in 2007 using Goddard’s Heterodyne Instrument for Planetary Wind and Composition (HIPWAC) observed warmer temperature in the equatorial region than in 2009. Having seen that the atmosphere can change, a lot more observations are needed to determine how so many phenomena can affect Venus' upper atmosphere over different intervals, according to the team.

"In addition to all these changes, we saw warmer temperatures than those predicted for this altitude by the leading accepted model, the Venus International Reference Atmosphere model," said Kostiuk. "This tells us that we have lots of work to do updating our upper atmospheric circulation model for Venus."

591985main_hipwac-irtf.jpg
The Heterodyne Instrument for Planetary Winds And Composition (HIPWAC) on the NASA 3-meter Infrared Telescope Facility (IRTF) on Mauna Kea Observatory in Hawaii. HIPWAC is the successor to the older Infrared Heterodyne Spectrometer (IRHS) instrument. Credit: NASA

Although Venus is often referred to as Earth's twin, since they are almost the same size, it ended up with a climate very different from Earth. A deeper understanding of Venus' atmosphere will let researchers compare it to the evolution of Earth's atmosphere, giving insight as to why Earth now teems with life while Venus suffered a hellish fate.

The team measured temperature and wind speeds in Venus' upper atmosphere by observing an infrared glow emitted by carbon dioxide (CO2) molecules when they were energized by light from the sun. Infrared light is invisible to the human eye and is perceived by us as heat, but it can be detected by special instruments. In the research, it appeared as a line on a graph from a spectrometer, an instrument that separates light into its component colors, each of which corresponds to a specific frequency. The width of the line revealed the temperature, while shifts in its frequency gave the wind speed.

The researchers compared observations from 1990 and 1991 using Goddard's Infrared Heterodyne Spectrometer instrument at NASA's Infrared Telescope Facility on Mauna Kea, Hawaii, to observations from 2009 using the Cologne Tunable Heterodyne Infrared Spectrometer instrument at the National Optical Astronomy Observatory's McMath Telescope at Kitt Peak, Ariz.

  Bill Steigerwald
NASA's Goddard Space Flight Center, Greenbelt, Md.
William.A.Steigerwald@nasa.gov

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#166 2015-08-25 21:31:21

SpaceNut
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From: New Hampshire
Registered: 2004-07-22
Posts: 29,433

Re: Mission to Venus

Void wrote:

Actually I am surprised that nobody picked up on this.
http://phys.org/news/2014-12-nasa-possi … venus.html

Actually interesting.  Might support the passage to Mars and Mars settlement in the long run I think.

equally surprised that no one pick up on this article Researchers mulling inflatable airship VAMP for flying the skies of Venus

Northrup Grumman and L'Garde are mulling the idea of a Venus Atmospheric Maneuverable Platform (VAMP) inflatable spacecraft—they have published an outline of their idea on NASA's web site. A craft that doesn't land on the surface, but instead simply flies around in the planet's atmosphere. To make that happen, they have designed an incredibly light (just 992 pounds) inflatable drone that doesn't require the development of any new technology

ftgyuukg.jpg

The VAMP would use engines (to turn propellers) that get their power from solar panels and the heat that escapes from a bit of onboard radioactive plutonium-238 as it decays. At night, the VAMP would serve as a glider making good use of its 151 foot wingspan.


Now if we use a blimp for the habitat and the plane as the transport of crew to it all that is needed now is an ability to land on the blimp or to hoover so that the crew could change ships.

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#167 2015-08-26 05:39:42

Tom Kalbfus
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Registered: 2006-08-16
Posts: 4,401

Re: Mission to Venus

SpaceNut wrote:
Void wrote:

Actually I am surprised that nobody picked up on this.
http://phys.org/news/2014-12-nasa-possi … venus.html

Actually interesting.  Might support the passage to Mars and Mars settlement in the long run I think.

equally surprised that no one pick up on this article Researchers mulling inflatable airship VAMP for flying the skies of Venus

Northrup Grumman and L'Garde are mulling the idea of a Venus Atmospheric Maneuverable Platform (VAMP) inflatable spacecraft—they have published an outline of their idea on NASA's web site. A craft that doesn't land on the surface, but instead simply flies around in the planet's atmosphere. To make that happen, they have designed an incredibly light (just 992 pounds) inflatable drone that doesn't require the development of any new technology

http://cdn.phys.org/newman/csz/news/800 … gyuukg.jpg

The VAMP would use engines (to turn propellers) that get their power from solar panels and the heat that escapes from a bit of onboard radioactive plutonium-238 as it decays. At night, the VAMP would serve as a glider making good use of its 151 foot wingspan.


Now if we use a blimp for the habitat and the plane as the transport of crew to it all that is needed now is an ability to land on the blimp or to hoover so that the crew could change ships.

The question is, is it going to fly blind? NASA has a previous history of sending blind atmospheric probes, they question is are we going to get a bunch of telemetry readings that only a scientist can appreciate. What do Venusian clouds look like from inside the atmosphere? Cameras are light and inexpensive these days, there is no reason to leave them behind! I remember the Soviet balloons, they floating around the atmosphere blind, couldn't see a thing. So is NASA going to send another blind probe and just have chemical analizers to blindly sample whatever cloud it happens to fly through?

What would a human see if he went there, seems scientists aren't interested in that, they might even forget to put windows in a manned craft. They don't seem to appreciate that a picture is worth a thousand words.

24342BD100000578-0-image-a-17_1419182793965.jpg
I'm not sure this is what astronauts would see if they flew in an airship in Venus' atmosphere, this is an artists interpretation, those clouds look Earthlike, because all the previous probes to Venus' atmosphere carried no cameras and sent back no pictures, this is kid of like the 1950s Chelsea Bonestell pictures of the Moon.
08_conquest_bonestell_theship-640x564.jpg
Notice how the peaks are sharp because it was assumed there was no erosion on the Moon. I wonder if the Venus picture of what the clouds would look like is based on scientists theories based on the numeric data they've received from their blind probes rather than from actual pictures?

Last edited by Tom Kalbfus (2015-08-26 05:48:49)

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#168 2015-08-26 09:32:46

RobertDyck
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From: Winnipeg, Canada
Registered: 2002-08-20
Posts: 7,936
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Re: Mission to Venus

SpaceNut wrote:

Now if we use a blimp for the habitat and the plane as the transport of crew to it all that is needed now is an ability to land on the blimp or to hoover so that the crew could change ships.

I was thinking the same thing. One of the web pages show a sky settlement supported with large round balloons, and blimps docking. But why blimps? For transport, use aircraft. An aircraft is much faster. Here is a video of a US military zeppelin as a carrier for biplanes. The aircraft have a hook on top, which catches an arm beneath the zeppelin. The arm then swings up, lifting the aircraft inside the zeppelin.
https://www.youtube.com/watch?v=IWoEQRl8dCs
Wikipedia: USS Macon

USS Macon (ZRS-5) was a rigid airship built and operated by the United States Navy for scouting and served as a "flying aircraft carrier", designed to carry biplane parasite aircraft, five single-seat Curtiss F9C Sparrowhawk for scouting or two-seat Fleet N2Y-1 for training. In service for less than two years, in 1935 Macon was damaged in a storm and lost off California's Big Sur coast, though most of the crew were saved. The wreckage is listed as USS Macon Airship Remains on the U.S. National Register of Historic Places.

Less than 20 ft (6.1 m) shorter than Hindenburg, both the Macon and "sister ship" USS Akron (ZRS-4) were among the largest flying objects in the world in terms of length and volume. Although the hydrogen-filled Hindenburg was longer, the two sisters still hold the world record for helium-filled airships.

If you want an aircraft based from a cloud city, do something like that. It's already proven to work. But both Akron and Macon were destroyed in storms. Make sure your city can endure storms.

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#169 2015-08-26 16:44:36

Tom Kalbfus
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Registered: 2006-08-16
Posts: 4,401

Re: Mission to Venus

RobertDyck wrote:
SpaceNut wrote:

Now if we use a blimp for the habitat and the plane as the transport of crew to it all that is needed now is an ability to land on the blimp or to hoover so that the crew could change ships.

I was thinking the same thing. One of the web pages show a sky settlement supported with large round balloons, and blimps docking. But why blimps? For transport, use aircraft. An aircraft is much faster. Here is a video of a US military zeppelin as a carrier for biplanes. The aircraft have a hook on top, which catches an arm beneath the zeppelin. The arm then swings up, lifting the aircraft inside the zeppelin.
https://www.youtube.com/watch?v=IWoEQRl8dCs
Wikipedia: USS Macon

USS Macon (ZRS-5) was a rigid airship built and operated by the United States Navy for scouting and served as a "flying aircraft carrier", designed to carry biplane parasite aircraft, five single-seat Curtiss F9C Sparrowhawk for scouting or two-seat Fleet N2Y-1 for training. In service for less than two years, in 1935 Macon was damaged in a storm and lost off California's Big Sur coast, though most of the crew were saved. The wreckage is listed as USS Macon Airship Remains on the U.S. National Register of Historic Places.

Less than 20 ft (6.1 m) shorter than Hindenburg, both the Macon and "sister ship" USS Akron (ZRS-4) were among the largest flying objects in the world in terms of length and volume. Although the hydrogen-filled Hindenburg was longer, the two sisters still hold the world record for helium-filled airships.

If you want an aircraft based from a cloud city, do something like that. It's already proven to work. But both Akron and Macon were destroyed in storms. Make sure your city can endure storms.

The only place to travel to would be this blimp, the blimp would be the equivalent in Venusian Terms to the Mars Hab and the Earth Return Vehicle. The main task of the blimp would be to carry the rocket that returns the astronauts to orbit, where a mother ship awaits to return the astronauts to Earth. The Earth Return Capsule would probably be the equivalent to a Gemini Capsule, it would carry two astronauts and maybe 50 pounds of rocks collected from the surface of Venus by remote drones. There would be very little else in the capsule besides that, The capsule would have enough life support to sustain the astronauts on the trip to orbit and docking with the mothercraft. My guess is the acceleration would be stiff, maybe up to 6 gees on the way up to orbit in order to save fuel. The "lander" would be a winged deorbiter, it would have either ablative heat shielding, or tiles like the Shuttle, probably it would make no sense to make the heat shield reusable as the craft would only be used once to enter the atmosphere, to get to the blimp, once it is established that the rocket it carries can take them back to orbit. After the mission is over, the blimp and the winged craft would be discarded. On the other hand the winged craft might be used multiple times as a manned airplane, it could take a human crew beneath the cloud layer and photograph the surface below, maybe if it was robust enough, it could even land on the surface, taking a human crew with it, heavily cooled of course. A plane would not need a runway to land on the planet's surface, the wings would be mostly of use in the thinner air above, close to the surface, traveling through the atmosphere would be like traveling through water, it could probably just settle on the surface, collect the rocks as quickly as it can and then take over before it overheats and kills the crew. It would them fly back to the blimp glowing red hot no doubt as it shed heat through its wing surface in the cooler atmosphere above, and then an Vertol engine would allow it to dock underneath the gondola of the blimp.

Last edited by Tom Kalbfus (2015-08-26 16:51:39)

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#170 2015-08-26 19:39:32

SpaceNut
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From: New Hampshire
Registered: 2004-07-22
Posts: 29,433

Re: Mission to Venus

From several of the posts collectively I do believe that we have put the thoughts together for an analog Venus cloud site that is simular to the Mars analogs for concept proof developement. Using the large blimp as the cloud platform to creat a habitat area with the capability to do not only science but do the needed testing of designs that might eventually be used for a real venus exploration. We not only have been thinking of thr ways to do a sample return but how to do an orbital redevous for the return trip home to Earth once we have gone and done the first steps. I am thinking that we could use a UV hardening epoxy to make the wings of the plane that we use as light wieght as possible for the trip from say the ISS to the cloud orbiting analog habitat making the heat shield expendable. The plane once it reaches the platform would land nearly empty of fuel to allow for refueling concepts of insitu resource useage for the return flight back to the ISS. The crew coming from the pretend orbiting venus station would hold the cache of food and water to travel down to the orbiting platform. IF the vehicle can not hold enough down mass for the floating station then we will need to make the heatshield reuseable.

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#171 2015-08-27 06:36:06

Tom Kalbfus
Banned
Registered: 2006-08-16
Posts: 4,401

Re: Mission to Venus

Problem is that it would be hard to repair and maintain a reusable Venusian Shuttle on site. There are certain options that won't work on Venus. A scramjet won't work for instance neither would any other air breathing space plane. I think a Venusian space plane would go in one direction only, from orbit to atmosphere, from that point it could extend its wings, props, and use solar power to maintain altitude. The other option is to build a nuclear airplane, but we have never built one before! Various people on Earth do not like nuclear reactors flying over their heads, this tends to discourage the development of them.

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#172 2015-08-27 18:51:08

SpaceNut
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From: New Hampshire
Registered: 2004-07-22
Posts: 29,433

Re: Mission to Venus

Nuclear-powered unmanned aerial vehicles (UAVs) that would increase operational flight durations from days to months are a technological possibility today, according to a feasibility study undertaken last year by Sandia National Laboratories and Northrop Grumman Systems Corporation.

103 pages of DESIGN OF A NUCLEAR PROPULSION SYSTEM FOR AN UNMANNED AERIAL VEHICLE

http://www.gizmag.com/nuclear-uav/22041/

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#173 2015-08-28 09:45:39

Tom Kalbfus
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Registered: 2006-08-16
Posts: 4,401

Re: Mission to Venus

I think we should try building the solar powered blimps and see if we can launch rockets into Earth orbit from them, if it works on Earth it should also work on Venus.

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#174 2015-08-28 22:33:31

Antius
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From: Cumbria, UK
Registered: 2007-05-22
Posts: 1,003

Re: Mission to Venus

A nuclear powered rocket vehicle may be the best way of transporting people and material between your cloud airship and Venus orbit.  Liquid nitrogen would be an acceptable propellant.

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#175 2015-08-29 18:53:31

Tom Kalbfus
Banned
Registered: 2006-08-16
Posts: 4,401

Re: Mission to Venus

Antius wrote:

A nuclear powered rocket vehicle may be the best way of transporting people and material between your cloud airship and Venus orbit.  Liquid nitrogen would be an acceptable propellant.

A nuke reactor would hang from a blimp, maybe its excess heat could be used to heat the carbon-dioxide making it a hot air blimp, the heating element would be radiators of a refrigerator that liquefies nitrogen from the Venusian atmosphere, or perhaps it will heat hydrogen to get that extra lift as the weight in the liquid nitrogen tanks build. This blimp would be high in the Venusian atmosphere so that the surrounding atmosphere would be cold compared to the hot hydrogen in the blimp. 58 km, according to this chart has a temperature of -13 centigrade.
t_on_venus_2.gif
This diagram plots altitude on Venus with atmospheric pressure.
venus-p.gif
So according to this chart, sea level pressure is at 49.5km So 58 km is 8.5 km higher., this is the equivalent of the height of Mount Everest, at Mount Everest's summit the air pressure is about one third that of Sea Level, I expect that since carbon-dioxide is a dense gas, the air pressure would diminish more quickly, but with Venus' lesser gravity this is reduced somewhat, still it would be quite cold. At 49.5 km the temperature is around 52 degrees centigrade, while at 58 km its below the freezing point of water, this is the equivalent of Jetliner cruising altitude on Venus.

Last edited by Tom Kalbfus (2015-08-29 18:56:54)

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