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Sending Men To Venus
ljk4-1
post Jul 28 2005, 06:21 PM
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QUOTE (BruceMoomaw @ Jul 21 2005, 08:27 PM)
The Niven story was "Becalmed In Hell", and he wrote it all the way back in (I believe) 1965.  I don't remember any liquid nitrogen in that suit; what I do remember was that it was supposed to be only for emergency use because the joints tended to lock up after a fairly short time in that heat.

The story -- although it's often reprinted -- really was another demonstration (there were quite a few) of the fact that Niven, early in his career, was pretty much a scientific ignoramus.  Consider: Venus is said to be pitch-black below the clouds (although, in that case, there's obviously no way the greenhouse effect could heat it up); they drop a "small probe" from the ship which is just an atmospheric probe (as if they wouldn't have done that countless times before dispatching a manned ship into the atmosphere); and there have been no unmanned surface landers before this expedition, with the result that our heroes are the very first to ever find out what Venus' surface actually looks like close up, or to obtain surface samples.  Gaaakk!  Amateur night.
*


Venera 8 had reported rather dark skies in 1972, but at the time they didn't know it had landed when the Sun was only 5 degrees above the horizon.

And I also recall that they considered the refraction at the surface to be so intense that theoretically one could look all the way around the planet.

And one more - the original manned Mars missions of von Braun in the 1950s did not anticipate unmanned probes scouting the way to the Red Planet. The first closeups of the Red Planet would have been by ships full of men. And I mean just men.

I presume the story also did not anticipate the concentrated sulfuric acid?

You could always say it took place in an alternate universe where Venus wasn't quite as nasty as ours and space exploration involved few robot probes.


--------------------
"After having some business dealings with men, I am occasionally chagrined,
and feel as if I had done some wrong, and it is hard to forget the ugly circumstance.
I see that such intercourse long continued would make one thoroughly prosaic, hard,
and coarse. But the longest intercourse with Nature, though in her rudest moods, does
not thus harden and make coarse. A hard, sensible man whom we liken to a rock is
indeed much harder than a rock. From hard, coarse, insensible men with whom I have
no sympathy, I go to commune with the rocks, whose hearts are comparatively soft."

- Henry David Thoreau, November 15, 1853

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Chmee
post Jul 28 2005, 06:39 PM
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QUOTE (BruceMoomaw @ Jul 21 2005, 09:27 PM)
The Niven story was "Becalmed In Hell", and he wrote it all the way back in (I believe) 1965.  I don't remember any liquid nitrogen in that suit; what I do remember was that it was supposed to be only for emergency use because the joints tended to lock up after a fairly short time in that heat.

The story -- although it's often reprinted -- really was another demonstration (there were quite a few) of the fact that Niven, early in his career, was pretty much a scientific ignoramus. 
*


Well, remember that in 1965, our knowledge of the surface of Venus was very limited. Niven may have been only writting according to the latest information at that time, so I wouldn't call him an ignoramus!

Now if we could just get Ringworld to be stable rolleyes.gif
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JRehling
post Jul 29 2005, 03:37 PM
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ljk4-1
post Jul 29 2005, 04:10 PM
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QUOTE (JRehling @ Jul 29 2005, 10:37 AM)
I feel the need to share this: I started fourth grade in 1978 -- the same year that Pioneer Venus arrived at Venus, and during that year, artists renditions of what would later be dubbed Devana Chasma appeared in our newspaper. Of course, it had been known for over a decade that the surface of Venus was very hot. However, my school district's funding being what it was, we had some significantly outdated materials in the classroom. I was participating in a self-graded exercise that began with my reading a short essay on the possibility of life on Venus, and this essay being from the early Sixties, it took a basic "Nobody knows" stance. When I answered the questions at the end, and one of them flatly asked if there was life on the surface of Venus, I drew upon the slightly-updated facts and said, "No." Then, in the self-grading phase, I would have been required to give myself an incorrect for that answer because the favored answer (in the early Sixties) was "Nobody knows". I stepped up to the teacher to ask her to make a ruling, and I ended up getting proper credit for my answer.
*


Circa 1995 I attended a friend's son's elementary school science fair in the Boston area. One child had an display on Earth's Moon and was using a book from 1963! The page he had it open to was the one about the three old scenarios of how Luna was formed (this was well before the impact theory).

I politely tried to explain to him about the new idea and that the book was rather outdated. He understood and accepted what I was saying, but it was also obvious that he couldn't just run off and make a new display. I was amazed that no parent or teacher cuaght this - but maybe I shouldn't be.

And then I encountered another display with an older student girl who had an outdated model of the Solar System. Somehow I got on the subject of other solar systems and extraterrestrial life with her, neither of which she somehow had even considered before. And this was not some rundown school in the middle of nowhere!


--------------------
"After having some business dealings with men, I am occasionally chagrined,
and feel as if I had done some wrong, and it is hard to forget the ugly circumstance.
I see that such intercourse long continued would make one thoroughly prosaic, hard,
and coarse. But the longest intercourse with Nature, though in her rudest moods, does
not thus harden and make coarse. A hard, sensible man whom we liken to a rock is
indeed much harder than a rock. From hard, coarse, insensible men with whom I have
no sympathy, I go to commune with the rocks, whose hearts are comparatively soft."

- Henry David Thoreau, November 15, 1853

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Guest_BruceMoomaw_*
post Jul 30 2005, 01:30 AM
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Oh, yes, the Niven story didn't mention the possibility of super-refraction producing a "bowl-shaped" surface on Venus -- buit then, that idea, which became briefly faddish in early 1970s SF (one of John Varley's first stories was "In the Bowl") turned out to be totally wrong as soon as the Soviets landed cameras. Indeed, it seems to be extremely hard to predict in advance the way an atmospheric planet's sky will look to a landed spacecraft; the various possible optical properties involved are just too complex, and very slight variations in them seem to have effects too great.

As for Venus' H2SO4 clouds: nobody seems to have guessed that one in advance before Earth-based studies nailed them in 1973 -- the closest anyone had come before was hydrochloric acid.

So Niven can hardly be blamed for missing those possibilities -- but he CAN be hammered, in no uncetain terms, for his portrayal of Venus as pitch-black below the clouds and his prediction that no unmanned landers would touch down before his crew did. Both those items, as I said, were violations of elementary scientific common sense, not subtle misses. (It's true that huge numbers of science writers had a strange blind spot in the early 1950s about unmanned probes showing us the vistas of new worlds before humans got there -- that turns up, in regard to the Moon's farside, in an Arthur C. Clarke story as late as 1957! Maybe they didn't want to believe it. But by 1965 there was no conceivable excuse even by that standard. Indeed, by 1963 Andre Norton -- not exactly the most scientifically reliable SF writer -- was writing about unmanned "peeper probes" being used to explore the past via time machine.)
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Guest_DonPMitchell_*
post May 10 2006, 11:06 PM
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If you haven't seen it, Voyage to the Planets and Beyond is a fun show about a 5-man mission to explore the planets. Produced by the BBC. They land on Venus, but not with anything that realistically could have done it. They show a sort of big LEM-like craft, which would never be able to get back into orbit.

A couple annoying technical mistakes: first they show (well in fact David Grinspoon claimed in the special festures) that you can see the surface from under the clouds. Not a chance. Purely from Rayleigh scattering, the visibility closes down to a matter of kilometers near the surface. V.I. Moroz first pointed that out, in an article about low-altitude balloon reconnaissance probes on Venus. Grinspoon also claimed the last spacecraft to land on Venus was Venera-14. (Can you actually make a documentary about space without having David Grinspoon or Neil deGrasse Tyson in it? Hehe.)

The Russians had a manned mission plan to Mars and Venus that was to be launched with the N-1: TMK-1.
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PhilHorzempa
post May 11 2006, 04:08 AM
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I would like to mention one of my pre-occupations, namely the long-term
terraforming of Venus. In that regard, I found Pete Worden's recent comments
on building a shield, to deal with Global Warming, quite intriguing. You can
read his comments here.

http://spaceref.com/news/viewnews.html?id=1119


I find Pete's idea quite fascinating. He suggests that we could launch
millions of small shields using material from the Moon. These shields would
be positioned at the L1 point and block enough sunlight to cool the Earth.


Now, consider this as applied to Venus. In order to allow manned inspection,
and colonization, of the surface of Venus, we will need to do 2 things. First,
lower the temperature and, second, decrease the surface pressure. A system
of millions of small shields would do the trick.

First, the temperature of Venus would need to be dropped to a level where the
CO2 would freeze out, thus lowering atmospheric pressure. The surface could
then be explored "in person." However, the landscape would be coated with
a thick layer of dry ice.

The next step to prepare for colonization would be to, somehow, get the dry ice
to react to form carbonates. This part I have not thought through in detail. However,
assuming that you could premanently sequester the CO2 as Carbonates, then one
opens up a whole new Earth for colonization.

This may take longer than terraforming Mars, but in the long term, I think that
humans will prefer a planet with a surface gravity of 1g as opposed to 1/3g.



Another Phil
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jamescanvin
post May 11 2006, 05:06 AM
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It's going to take an awfully long time for a rock the size of Veus to cool enough to freeze CO2 I would imagine.

I remember reading (a long time ago) of another idea, that would have split the CO2 atmosphere into an O2 one with a lot (and I mean a lot) of carbon dust coving the surface, although quite how that helps matters I can't remember! blink.gif

But anyway, why get rid of the atmosphere when it provides such a nice habitat at 50km... smile.gif

http://powerweb.grc.nasa.gov/pvsee/publica...ony_STAIF03.pdf

James


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Phil Stooke
post May 11 2006, 05:13 AM
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I think Carl Sagan discusses this in Pale Blue Dot.

Phil


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... because the Solar System ain't gonna map itself.
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dilo
post May 11 2006, 06:04 AM
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QUOTE (jamescanvin @ May 11 2006, 05:06 AM) *
But anyway, why get rid of the atmosphere when it provides such a nice habitat at 50km... smile.gif
http://powerweb.grc.nasa.gov/pvsee/publica...ony_STAIF03.pdf
James

Wow, "cities designed to float at about fifty kilometer altitude in the atmosphere of Venus"... ohmy.gif
This is an intriguing idea, it recall me the cloud city from "Empire Stikes Back"! rolleyes.gif


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helvick
post May 11 2006, 08:02 AM
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QUOTE (dilo @ May 11 2006, 07:04 AM) *
Wow, "cities designed to float at about fifty kilometer altitude in the atmosphere of Venus"... ohmy.gif
This is an intriguing idea, it recall me the cloud city from "Empire Stikes Back"! rolleyes.gif


Saturn would be much more suitable for a floating city- you have plenty of raw material nearby (in the Saturnian moons) and gravity at reasonable atmospheric depths is still close to 1g.
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Guest_DonPMitchell_*
post May 11 2006, 10:03 AM
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QUOTE (helvick @ May 11 2006, 01:02 AM) *
Saturn would be much more suitable for a floating city- you have plenty of raw material nearby (in the Saturnian moons) and gravity at reasonable atmospheric depths is still close to 1g.


Ah, I didn't realize Saturn is only 1.1 g. Still, it's pretty cold there.

The idea of building a thermal shield is actually Edward Teller's. He also proposed using dust in the stratosphere to fight global warming.

The time constant for Venus is about 100 years. If you could cut off enough sunlight, you'd have to wait a couple centuries for it to reach equilibrium again. I believe if you could get rid of the cloud cover, the cooling process would speed up some. At lower temperatures, some of the CO2 would start to be absorbed into the crust by the natural transformation of silicates into carbonates. That might take a long time. Some estimate that the Earth would have a sealevel pressure of 20 atm if all carbonates were broken down.

I'm not a big fan of short-term expensive one-time manned missions. I'm proud that we did the Apollo missions, but the cost was staggering -- more than 5 percent of the total federal budget was spent for several years. I don't even like the ISS.

But I am a fan of terraforming. I don't think human space travel will make sense until there is a real destination for people. A normal human being will go to Mars because he can live there, he can start a new life or be with people who already live there. People compare spacetravel to airtravel, but think about why airtravel is a big industry. I don't fly from Seattle to Minnesota to pick up a rock and them come home. I fly there to visit my family.

I think economics ultimately drives huge ventures. You just can't colonize a planet by pure romantic energy alone. You have to engage productive and practical people, who actually do things in society. It's basically a real estate development project, but what kind of financial instrument can you create that people will believe in, but which returns on investment in 200 years? There is a problem for you in applied economics: Mars Real Estate Futures!
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Bob Shaw
post May 11 2006, 02:10 PM
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QUOTE (dilo @ May 11 2006, 07:04 AM) *
Wow, "cities designed to float at about fifty kilometer altitude in the atmosphere of Venus"... ohmy.gif
This is an intriguing idea, it recall me the cloud city from "Empire Stikes Back"! rolleyes.gif



Marco:

You're about a week late - this post *should* have been made on Bewithyou Day, which is the date immediately preceding May the 5th.

Bob Shaw


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Remember: Time Flies like the wind - but Fruit Flies like bananas!
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ljk4-1
post May 11 2006, 02:17 PM
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QUOTE (DonPMitchell @ May 11 2006, 06:03 AM) *
But I am a fan of terraforming. I don't think human space travel will make sense until there is a real destination for people. A normal human being will go to Mars because he can live there, he can start a new life or be with people who already live there. People compare spacetravel to airtravel, but think about why airtravel is a big industry. I don't fly from Seattle to Minnesota to pick up a rock and them come home. I fly there to visit my family.


Rather than try to change an entire planet's ecosphere, how about we
change humans genetically to fit the environment?

If we could tailor-make people to survive on other worlds as they exist
now, we could have humans on virtually every world in the Sol system
and beyond. The future survival of our species would be assured.

http://www.kurzweilai.net/email/newsRedire...sID=5531&m=7610


--------------------
"After having some business dealings with men, I am occasionally chagrined,
and feel as if I had done some wrong, and it is hard to forget the ugly circumstance.
I see that such intercourse long continued would make one thoroughly prosaic, hard,
and coarse. But the longest intercourse with Nature, though in her rudest moods, does
not thus harden and make coarse. A hard, sensible man whom we liken to a rock is
indeed much harder than a rock. From hard, coarse, insensible men with whom I have
no sympathy, I go to commune with the rocks, whose hearts are comparatively soft."

- Henry David Thoreau, November 15, 1853

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Guest_DonPMitchell_*
post May 12 2006, 02:54 AM
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QUOTE (ljk4-1 @ May 11 2006, 07:17 AM) *
Rather than try to change an entire planet's ecosphere, how about we
change humans genetically to fit the environment?

If we could tailor-make people to survive on other worlds as they exist
now, we could have humans on virtually every world in the Sol system
and beyond. The future survival of our species would be assured.

http://www.kurzweilai.net/email/newsRedire...sID=5531&m=7610


That's an intersting idea, but I don't think you could breed people who breath CO2 instead of oxygen, or who could live at cryogenic temperatures or pyrolyzing temperatures. The chemisty of life is just impossible. The only life forms I could imagine would be machine-based, but not organic.
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