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Unmanned Spaceflight.com _ Venus _ Sending Men To Venus

Posted by: gndonald Jul 20 2005, 04:40 PM

While it is likely that future Venus missions will be robotic craft, at one point someone in NASA carried out an interesting contingency study on sending a manned craft to orbit Venus.

The file (Click here:http://tinyurl.com/b8gk5) works on the assumption that either the NERVA project had been carried through to completion or that NASA had retained the capacity it was developing for Apollo.

While the author does not rule out the possibility of a landing on Venus, he notes that owing to the unknown surface conditions they would be highly unlikely.

Launch times are given as being between 1975-1986 and are designed to allow 40 days in orbit at Venus.

As someone who was growing up during the period mentioned I would like to say that such missions would have been far more interesting than what actually occurred.

Posted by: BruceMoomaw Jul 20 2005, 07:04 PM

Keep in mind that one of the main reasons for being hesitant to land men on Mars if we DO discover proof of either present or fossil life (which is virtually the only thing that could conceivably justify such a staggeringly expensive feat for at least the next 50 years) is that manned landers obviously cannot be sterilized -- which means that any attempt to use manned landers to study evidence of Martian life will disastrously contaminate the very thing they're trying to study. (I call "the Martian Catch-22.")

For this reason, it might be far more defensible to limit any manned Mars expeditions -- for a long time to come -- to orbiting the planet, so that the crew could teleoperate sophisticated sterilized surface rovers, sample-return landers, etc. without the lengthy radio time lag that makes it so extremely dificult to study any other planet by remote control directly from earth. But exactly that same kind of manned expedition -- a manned orbiter telecontrolling a large array of unmanned surface vehicles in a fast and efficient way -- could be used to explore Venus. So a manned Venus mission is not quite as crazy an idea as it might at first appear to be.

Posted by: gndonald Jul 21 2005, 03:14 AM

I don't think that a manned Venus mission would be either a crazy or fruitless idea, in fact a program of manned missions leading to an ISS style station in orbit around Venus as a permanent base for running remote surface surveys would have been a wonderful objective for NASA during the 'post-Viking' period.

But that would have required a degree of political backing that was sadly lacking during the 1976-1986 timeframe.

Posted by: JRehling Jul 21 2005, 03:45 AM

[...]

Posted by: mike Jul 21 2005, 05:07 AM

Shielding would have to be a part of the design, but even then, it's space, it's dangerous. I think the astronauts realize that, and I think people in general know that. I dare say that the danger is no small part of the appeal of exploration. If it were completely safe, it would also be completely boring.

Posted by: edstrick Jul 21 2005, 06:59 AM

Note that Venus actually includes environments where a non-spacesuited human can actually go outside. At (I don't have the exact number) about 50 or 55 kilometers altitude, the atmosphere temperature is about 70 F and the pressure is very roughly 1/2 atmosphere. The concentrated sulfuric acid clouds are actually a moderatly thick haze of 2 micrometer droplets with visibility of at least many hundereds of meters to a few kilometers

With a 40% oxygen/nitrogen air supply and goggles, and an acid blocking/neutralizing cream on the skin, and acid-resistant clothing, you could actually work on the outside of a "Buoyant Venus Station" for extended periods.

Posted by: Bob Shaw Jul 21 2005, 09:08 AM

Here's a thought: Venus, at closest approach, is only about 100 times further away than the Moon, and about 25 times further away than Earth's furthest LaGrange point...

Posted by: ljk4-1 Jul 21 2005, 03:25 PM

In his 1997 book Venus Revealed, David Grinspoon included a drawing of a proposed manned research station floating in the Venerean atmosphere.

Here it is:

http://www.funkyscience.net/imagebank/image_ills/researchstation.jpg

He also has some interesting speculation on the life forms that might dwell in those "nicer" regions.

Posted by: Chmee Jul 21 2005, 03:35 PM

Larry Niven wrote a good short story back in the seventies about a manned landing on Venus, (who got stuck on the surface and had to find a way to get off). I beleive the main character had an environment suit that had a layer of liquid nitrogen in it so he could stay cool enough to walk around the surface for an hour or two...

Posted by: Bob Shaw Jul 21 2005, 08:31 PM

QUOTE (ljk4-1 @ Jul 21 2005, 04:25 PM)
In his 1997 book Venus Revealed, David Grinspoon included a drawing of a proposed manned research station floating in the Venerean atmosphere.

Here it is:

http://www.funkyscience.net/imagebank/image_ills/researchstation.jpg

He also has some interesting speculation on the life forms that might dwell in those "nicer" regions.
*


Just so long as there's no light-sabre fights down near that downward-pointing antenna... ...gotta hand it to you, Dad (Ouch!)!

Posted by: Chmee Jul 21 2005, 08:33 PM

QUOTE (Bob Shaw @ Jul 21 2005, 04:31 PM)
Just so long as there's no light-sabre fights down near that downward-pointing antenna... ...gotta hand it to you, Dad (Ouch!)!
*


Dont worry, if there is a fight, the Millenium Falcon will come back and rescue Luke.

Posted by: ljk4-1 Jul 21 2005, 08:55 PM

QUOTE (Chmee @ Jul 21 2005, 03:33 PM)
Dont worry, if there is a fight,  the Millenium Falcon will come back and rescue Luke.
*


Just what the heck did hold up Bespin? Could anti-grav units really do the trick? And just what were they mining up there anyway?

And how can we relate this technology to a manned Venus platform?

Posted by: BruceMoomaw Jul 22 2005, 01:19 AM

QUOTE (ljk4-1 @ Jul 21 2005, 08:55 PM)
Just what the heck did hold up Bespin?  Could anti-grav units really do the trick?  And just what were they mining up there anyway?

And how can we relate this technology to a manned Venus platform?
*


I believe they were mining hot air, of which there was an impressive supply in the Star Wars saga.

Posted by: BruceMoomaw Jul 22 2005, 01:27 AM

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.

Posted by: Phil Stooke Jul 28 2005, 06:07 PM

Actually, there are a few people I would like to send to Venus. And strangely, most of them are men.

Phil

Posted by: ljk4-1 Jul 28 2005, 06:21 PM

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.

Posted by: Chmee Jul 28 2005, 06:39 PM

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

Posted by: JRehling Jul 29 2005, 03:37 PM

[...]

Posted by: ljk4-1 Jul 29 2005, 04:10 PM

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!

Posted by: BruceMoomaw Jul 30 2005, 01:30 AM

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.)

Posted by: DonPMitchell May 10 2006, 11:06 PM

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: http://www.astronautix.com/craft/tmk1.htm.

Posted by: PhilHorzempa May 11 2006, 04:08 AM




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

Posted by: jamescanvin May 11 2006, 05:06 AM

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/publications/venus/VenusColony_STAIF03.pdf

James

Posted by: Phil Stooke May 11 2006, 05:13 AM

I think Carl Sagan discusses this in Pale Blue Dot.

Phil

Posted by: dilo May 11 2006, 06:04 AM

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/publications/venus/VenusColony_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

Posted by: helvick May 11 2006, 08:02 AM

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.

Posted by: DonPMitchell May 11 2006, 10:03 AM

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!

Posted by: Bob Shaw May 11 2006, 02:10 PM

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

Posted by: ljk4-1 May 11 2006, 02:17 PM

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/newsRedirect.html?newsID=5531&m=7610

Posted by: DonPMitchell May 12 2006, 02:54 AM

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/newsRedirect.html?newsID=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.

Posted by: Phil Stooke May 12 2006, 03:27 AM

I'm all in favour of sending people to Venus, as long as I get to choose who goes! And I have a few candidates already.

Phil

Posted by: dvandorn May 12 2006, 04:19 AM

QUOTE (Phil Stooke @ May 11 2006, 10:27 PM) *
...I have a few candidates already.

So do I... we *are* talking about just sending them to Venus, right? Not worrying a wit about even *trying* to bring them back, right?

biggrin.gif

-the other Doug

QUOTE (Bob Shaw @ May 11 2006, 09:10 AM) *
...this post *should* have been made on Bewithyou Day, which is the date immediately preceding May the 5th...

Grrrooaannn...

blink.gif

-the other Doug

Posted by: ljk4-1 May 24 2006, 05:06 PM

Here is a depiction of a manned USSF Venus expedition (you know
this because they wrote it in big red letters on the side of the ships)
from Erik Bergaust's 1962 children's book titled Space Stations:

http://sun3.lib.uci.edu/~jsisson/gifs/stat1.gif

If you haven't already, check out the Web site Dreams of Space with
all the glorious books from our childhood (or not):

http://sun3.lib.uci.edu/~jsisson/john.htm

When all spaceships looked like either V-2 rockets or tubes with balls
attached to them, the Moon was always craggy and the mountains sharp,
Earth never had clouds and always showed its Western Hemisphere, and
the daring astronauts were all brave, serious, and men. Except when they
depicted children, then it was usually a boy and girl travelling to the Moon
together.

Posted by: BruceMoomaw May 24 2006, 11:52 PM

Of course, those were also the days when every superhero worth his salt had a little boy and a little girl assisting him, too. James Thurber wrote: "I don't know what the parents of these children can be thinking of. When they should be at home or in bed or in school, they are usually trapped in a burning elevator shaft, or lying bound and gagged somewhere."

Posted by: DonPMitchell May 25 2006, 12:27 AM

QUOTE (BruceMoomaw @ May 24 2006, 04:52 PM) *
Of course, those were also the days when every superhero worth his salt had a little boy and a little girl assisting him, too. James Thurber wrote: "I don't know what the parents of these children can be thinking of. When they should be at home or in bed or in school, they are usually trapped in a burning elevator shaft, or lying bound and gagged somewhere."


Kids get into the darnedest things when you're not keeping an eye on them

[attachment=5853:attachment]

Posted by: AndyG May 25 2006, 08:04 AM

QUOTE (ljk4-1 @ May 24 2006, 06:06 PM) *
If you haven't already, check out the Web site Dreams of Space with
all the glorious books from our childhood (or not):

http://sun3.lib.uci.edu/~jsisson/john.htm

Wow! But wait! "The Monkey in the Rocket" http://sun3.lib.uci.edu/~jsisson/gifs/monkey.gif is illustrated by...no...it can't be!? Sergio Leone?? ohmy.gif

Andy G

Posted by: Bob Shaw May 25 2006, 12:39 PM

Don:

Many thanks for posting an image with tentacles in it, especially of the deep, hungry, questing and wet variety! You have made my day!

Seriously, though, a number of years ago I was lucky enough to go on a day trip to the bottom of Loch Ness (yup, that one) in a decommissioned Deep Sea Rescue Vehicle. For some reason the DSRV had been sold for a song by the US Navy, and had found it's way to Scotland. Although designed to carry dozens of stranded submariners, it only carried six people on the trip I took, so it was seriously roomy and not in the least bit terrifying. The Tom Swift book cover made me chuckle, because although obviously a naive 1950s effort it nevertheless was a reasonably accurate prediction of what the DSRV actually would look like! Unlike most submarines, the DSRV actually had a big glass nose, lots of space, and even a baby conning tower - so maybe some more Tom Swift gadgets will come to pass!

Oh, and we saw no sign of anything monstery in Loch Ness; not a flipper, not a tentacle, not a thing!

Bob Shaw

Posted by: BruceMoomaw May 25 2006, 01:32 PM

While, we're wandering off on this somewhat irrelevant subject, Allan Steele -- who's written some fairly good hard-science SF stories about the future exploration of the Solar System -- did one for "F&SF" a few years ago about Tom Swift Jr.'s wastrel son Tom Swift III, who spends most of his time getting as high as a kite and accidentally activates Dad's Giant Robot to go on a rampage through the local town (whose name I can't quite recall -- "Swiftville", wasn't it? Makes you wonder how Tom Swift Sr. felt about unions.)

Eventually, however, Tom manages to rise to the occasion of getting the Robot back under control (thereby avoiding a longer jail sentence than he would otherwise have received), and resolves to straighten up and follow in Dad's footsteps. "Little did Tom know that soon his HYDROPONIC MARIJUANA CULTIVATOR would lead him into an exciting adventure in the South Pacific."

Posted by: Richard Trigaux May 25 2006, 02:17 PM

QUOTE (Bob Shaw @ May 25 2006, 12:39 PM) *
Oh, and we saw no sign of anything monstery in Loch Ness; not a flipper, not a tentacle, not a thing!

Bob Shaw



The problem is that the Loch Ness monster is visible only to BELIEVERS. Try harder, the next time. wink.gif

Posted by: MarkG Jun 28 2006, 02:42 AM

Incidentally, there's a much more detailed file about a proposed NASA mission to Venus using Apollo hardware at:

http://ntrs.nasa.gov/archive/nasa/casi.ntrs.nasa.gov/19790072165_1979072165.pdf

It's a while since I read through the whole thing (it's a couple of hundred pages) but from what I remember it didn't require any nuclear engines, just an uprated Saturn V (probably with solid boosters attached to the first stage).

Posted by: Holder of the Two Leashes Jun 28 2006, 04:44 AM

QUOTE (helvick @ May 11 2006, 03:02 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.

It would be hard to get things to float on Saturn, given that the atmosphere is mostly hydrogen. Hot air ballooning would be possible, but still, you're not talking about much lift. On the other hand, a dense CO2 atmosphere has plenty to offer, even if you're using a breathable N2/O2 mix as the lifting gas. As for raw materials, future technology might allow for carbon nanotubes to form the shell of a buoyant structure, in which case the carbon could be mined from the atmosphere.

Then there is the weather... from what I know I'd rather take my chances above Venus than in Saturn.

And personally, I much prefer 0.9 g to 1.1 g, easy way to lose 20 lbs.

Posted by: Bob Shaw Jun 28 2006, 12:30 PM

Mark:

Great link!

It's basically a plan to send a wet workshop S-IVB to Venus, with a new mission module between the S-IVB and the Apollo spacecraft. Included would also be one or more Venus probes. All in all, it looks like a comfortable way to fly to another planet - though the radiation discussion is quite scary (eye cataracts due to radiation damage would be no problem, as onset would be after mission end...). The Apollo SM might be provided with an SPS backup capability altered to use two LM descent engine packages instead of the SPS, and - oddly - the configuration at Earth departure would be similar to current Lunar EOR plans, with the CSM docked to the Mission Module and thus flying backwards. The development process included a test mission in high (25,000 miles) Earth orbit, and was seen as being linked to space station development too.

Is there a word for nostalgia for things which never took place?

Bob Shaw

 

Posted by: MarkG Jun 28 2006, 06:27 PM

Yeah, would have been an exciting trip if it had happened smile.gif. I'd never really considered the radiation risks in that way, but I guess when you're in space for a year and going even closer to the sun there's always a strong risk of some kind of solar flare coming your way.

I'm trying to get that one simulated in Orbiter, but it will take a while.

Posted by: DonPMitchell Jun 29 2006, 05:50 AM

Interesting ideas. The Russian spacecraft designer Gleb Maksimov also planned a series of nuclear powered "Heavy Interplanetary Ships" (TMK in Russian) in the late 1950s and early 1960s.

[attachment=6468:attachment]

Personally, I'd be excited if NASA was building a ship like this, at least more than I am about us spending $100 billion on the ISS. I think there are two problems that have to be addressed. First, how do you prevent the astronauts from getting fried by charged-particle radiation? And second, can human beings actually do any solid science on such a missions, that couldn't be done more cheaply by robots?

Posted by: MarkG Jun 29 2006, 09:50 AM

QUOTE
And second, can human beings actually do any solid science on such a missions, that couldn't be done more cheaply by robots?


Yeah, I think that's the real issue. Unlesss you're going to send humans to live for a long period on the planet with the capability to travel widely and perform experiments along the way, odds are robots will do the same job for much less money.

Posted by: JRehling Jun 29 2006, 02:19 PM

[...]

Posted by: DonPMitchell Jun 29 2006, 07:32 PM

QUOTE (JRehling @ Jun 29 2006, 07:19 AM) *
That hasn't stopped ISS.


But perhaps it should. As you know, many Americans are not happy about ISS. We are spending most of the money on something that seems to just be a "feel good" political venture.

Posted by: dvandorn Jun 29 2006, 11:58 PM

Enough with the anti-manned-spaceflight agenda?

Please?

-the other Doug

Posted by: DonPMitchell Jun 30 2006, 12:54 AM

QUOTE (dvandorn @ Jun 29 2006, 04:58 PM) *
Enough with the anti-manned-spaceflight agenda?

Please?

-the other Doug


An opinion is not an "agenda". But since Bruce Moomaw was kicked off this forum for expressing that opinion, I guess I should watch out, eh? I don't think we should stifle people's opinions, just becaues we disagree with them. It is not an unusual opinion to think ISS is an unsound project.

I am not opposed to manned spaceflight. I am opposed to wasteful manned spaceflight. ISS is expensive and has little real scientific value. If nations were paying equally for it, I might feel better about the "Every country gets to have an astronaut!" concept. But ISS and the shuttle are a serious drain on NASA's resources now.

People should go into space when there is a real destination, not just as a publicity stunt. We should start thinking about robotic terriforming projects, for example. Or figure out a commercial value for space stations, like for example human entertainment.

Posted by: elakdawalla Jun 30 2006, 02:25 AM

The issue with Bruce Moomaw was not which opinion he held but the fact that discussions he participated in tended to become manned - vs - unmanned arguments, inspiring lots of ranting by him and others, regardless of the original topic under discussion. After discussion with the other admins Doug has decided that the debate isn't constructive toward the stated point of this forum -- discussing unmanned spaceflight. It's not that your or anyone else's specific opinion on the subject isn't 'approved' here; the whole discussion isn't approved, because it derails other discussions. Doug has asked people to refrain from beginning manned-vs-unmanned arguments, and has banned Bruce and others from the forum for failing, first, to honor that restraint and, second, to respond to his requests to desist. I'm sure each of us has a strong opinion on the topic but for the sake of this forum we are all being asked to follow the same rule and keep those opinions off the table.

--Emily

Posted by: centsworth_II Jun 30 2006, 02:45 AM

It could be argued that the "Venus" forum on UMSF is for discussion of UNMANNED missions and this thread on a fantastical manned mission is out of place. The appearance of a manned flight thread in an unmanned flight forum invites comment on manned missions in general.

There is a specific forum for discussion of manned missions, real or imagined.

edit: I'm not against any mention of manned flight in any of the forums, I think it has its place. It's useful to use a theoretical human mission to discuss the environment of a planet, moon, etc. But I don't think the philosophy or nuts-and-bolts of a manned mission should be discussed outside of the manned flight forum.

Posted by: DonPMitchell Jun 30 2006, 03:32 AM

"Sending Men To Venus" has had some interesting ideas. Should a manned orbiter control a rover? That's sort of a manned and an unmanned mission. The argument was made that if ISS is successful, then manned orbit of Mars or Venus would be successful. But that begs the question of the usefullness of ISS.

To me, unmanned spaceflight serves a short term goal of answering scientific questions. But I think it can have a long-term goal of preparing the way for manned exploration or colonization.

There is an important issue of how to plan that efficiently, but unfortunately, the space programs of every nation have been highly political. America sent men to the Moon because it had become a contest between the USA and USSR to prove who had the superior society. For China its propoganda, maintaining control of a dictatorship. For Europe, its a source of pride and emerging national identity as a union.

But given $100 billion, how do you make the most progress? Do you blow it on collecting one rock from Mars, and then never go back again? Do you build an expensive new space station to explore low-Earth orbit, so thoroughly understood already? Or do you dole it out to a series of robotic missions that lead up to some actual plan?

I don't see that plan. ISS and Bush's Mars and Moon missions all seem like missions with a politcial agenda. And scientists struggle and compete over the remaining slice of the NASA pie. Does everyone else believe things are just fine as they are?

This becomes a controversy only when people lose their tempers instead of engaging in discussion.

Incidently, I assume this thread can be moved to the "manned flight" folder at any time. Why not do so?

Posted by: RNeuhaus Jun 30 2006, 03:39 AM

I would rather change the forum name from UMSF to SF. The guygs who are participating this forum aren't only bond to unmanned space flights but also of manned ones. Both are complementary. The manned space flights depends from unmanned space flights since the unmanned ones are the first to conquer the unknown frontiers. Then, the unmanned space flight will depend from manned space for a more advanced explorations that might happen in the future such as children spaceships obeying the commands from the mother spaceships to facilite special explorations.

Rodolfo

Posted by: centsworth_II Jun 30 2006, 04:41 AM

QUOTE (RNeuhaus @ Jun 29 2006, 11:39 PM) *
The [guys] who are participating this forum aren't only [bound] to unmanned space flights but also of manned ones. Both are complementary.

Not with the current budget. Sure, it would be great to plan a manned orbiting mission to Mars and talk about all the wonderful robots that they could control on the surface from orbit. But this is pure science fiction for the forseeable future.

Unfortunately the reality is that manned and unmanned missions are competing, fiercely, for sparce budget dollars.

Posted by: djellison Jun 30 2006, 07:25 AM

QUOTE (RNeuhaus @ Jun 30 2006, 04:39 AM) *
I would rather change the forum name from UMSF to SF.


Not going to happen. Ever. Want a place to talk about manned spaceflight in a major way, make one yourself. The manned spaceflight section here has been THIS CLOSE (fingers close together) to getting culled, because it's the place where 90% of the arguments, flame wars and resultant bans and mod activity have to happen.

There are plenty of places that disucss manned spaceflight...but very few that do what this place does.

Doug

Posted by: AlexBlackwell Jun 30 2006, 04:52 PM

QUOTE (RNeuhaus @ Jun 30 2006, 03:39 AM) *
I would rather change the forum name from UMSF to SF. The guy[]s who are participating this forum aren't only bond[ed] to unmanned space flights but also...manned ones.

Well, since Doug owns this forum, that's his call to make, though I'm sure he appreciates the input.

But for those who feel that their particular opinions are getting short shrift here, there's a http://www.blogger.com/home to cure that. Once you get up and running, let me know. I'd love to read what you (and others) have to write on a given subject -- elsewhere.

Posted by: centsworth_II Jun 30 2006, 05:45 PM

QUOTE (AlexBlackwell @ Jun 30 2006, 12:52 PM) *
Well, since Doug owns this forum, that's his call to make...

Doug receives much deserved praise for maintaining a place for intelligent discussion of UMSF. He rightly (IMHO) sees that this quality would be jepardized if the forums were opened to discussion of manned flight. I generally trust current UMSF members, but once the Buck Rogers, spaceplane types showed up I would face the same problem picking through the forums for realistic, rational discussion of UMSF as I do on other web sites.

Posted by: JRehling Jun 30 2006, 06:26 PM

[...]

Posted by: dvandorn Jun 30 2006, 08:08 PM

Don, I must say that, with your clarifications, I agree with you much more than I don't.

This thread is good, I think -- though there is a definite self-limiting factor to a manned Venus orbiter right now (energetic cosmic rays and solar flares, with no really good way to shield against them). To safely operate manned vehicles at Venus, I think you'd first need to maneuver an asteroid into orbit around it and dig your manned vehicle into that asteroid. (Unlike Mars, Venus doesn't present us with a ready-made natural piece of real estate in the right location.)

I somehow get a feeling that, by the time we know enough to be able to maneuver asteroids into planetary orbits, we'll have come up with a shielding solution for energetic particles...

-the other Doug

Posted by: edstrick Jul 1 2006, 07:54 AM

It's not THAT difficult to shield solar cosmic rays. They're relatively low energy. You do need pounds of mass <perferably low atomic weight mass> per square inch surrounding you (sea level on earth has 14 pounds of mass per square inch over it)

What's a real problem is high atomic weight high energy galactic cosmic rays. But 14 lb/sq-in stops most of them, and shatters most into smaller and lower energy particles (cosmic-ray showers, they call'm)

The problem is the simple one of having to live inside a radiation shelter most of the mission. And you have to take that mass with you whereever you go.

Posted by: DonPMitchell Jul 1 2006, 10:10 AM

I worked on the heavy-nuclei detector in HEAO-C. We actually calibrated it in space using iron nuclei, which are pretty abundant in cosmic rays. I've heard that astronauts occasionally see flashes of light, when one of these passes through their eye and generate Cherenkov radiation.

There has been some research on using strong magnetic fields to shield a craft from cosmic rays. I don't know if that is practical or not.

Perhaps research on suspended animation will open up better possibilities for dealing with multi-year interplanetary missions -- allowing a crew to be kept safe in small shielded areas, and eliminating the need for massive supplies. Some dogs have been maintained in a clinically dead state for many hours without ill effect. But it's far from perfected or safe at this point.

Posted by: Bob Shaw Jul 1 2006, 11:34 AM

QUOTE (DonPMitchell @ Jul 1 2006, 11:10 AM) *
I worked on the heavy-nuclei detector in HEAO-C. We actually calibrated it in space using iron nuclei, which are pretty abundant in cosmic rays. I've heard that astronauts occasionally see flashes of light, when one of these passes through their eye and generate Cherenkov radiation.


Don:

I think the mechanism for 'seeing' cosmic rays actually involves direct stimulation of the optic nerve - the eyes aren't involved at all.

It's still scary!

Bob Shaw

Posted by: JRehling Jul 1 2006, 12:14 PM

[...]

Posted by: dvandorn Jul 1 2006, 12:26 PM

QUOTE (Bob Shaw @ Jul 1 2006, 06:34 AM) *
Don:

I think the mechanism for 'seeing' cosmic rays actually involves direct stimulation of the optic nerve - the eyes aren't involved at all.

It's still scary!

Bob Shaw

Were there ever a set of results posted for the ALFMED experiments flown during Apollo lunar missions? They had a nice setup, with a head-enclosing box that contained film on five of six sides. The idea was that you'd be able to calibrate film hits against taped reports of light flashes reported by the test subjects.

One of the things this was supposed to settle was whether the crews were seeing real light generated inside their eyeballs, or whether the flashes were indeed the result of direct hits on the optic nerves of the brain.

I don't ever recall seeing any results that settled this question. Anyone have any more info about it?

-the other Doug

Posted by: dvandorn Jul 1 2006, 12:29 PM

QUOTE (JRehling @ Jul 1 2006, 07:14 AM) *
This calls to mind the idea of having a large "dead" space station anywhere you want to revisit -- a shield that is heavy and needs to be put in place, but only once, for future missions to crawl inside it like a crab, then leave (or be pried out) when they're done. Incidentally, it could be done for robotic flights as well as manned, if you had a known orbital niche you wanted to revisit. For example, a Jupiter orbiter between Io and Europa. One dedicated launch to put the big shield/shell in place could create a home for many future missions. Sort of like the infrastructure effort in putting a comsat in place, except the shieldsat could conceivably last ~forever.

Why send such things, when you can use piles of rock and ice that Nature has provided? Assuming you can find piles of ice and rock in the orbits you want to use, of course.

Really, though -- just dig into a low-mass moon or asteroid, and you're all set. This would work for most of the worlds in our system, with the exceptions of Mercury and Venus...

-the other Doug

Posted by: MarkG Jul 1 2006, 07:28 PM

QUOTE
Why send such things, when you can use piles of rock and ice that Nature has provided? Assuming you can find piles of ice and rock in the orbits you want to use, of course.


Provided you can put a few tens of thousands of tons of hardware into orbit even that isn't an issue. Find a small near-Earth asteroid, land a mass-driver and some kind of decent power plant -- be it nuclear or solar -- on the asteroid and your 'home' also becomes your fuel supply. It won't get anywhere fast, but by throwing the rock out the back of the mass-driver you can take it to orbit pretty much any planet in the solar system.

Personally though I doubt people will ever land on another planet until they're doing it as a tourist trip. Venus is really kind of a no-hoper due to the atmosphere and surface conditions, where unmanned probes are clearly superior to humans (though obviously rovers controlled from orbit could move faster than rovers controlled from Earth), and while the Apollo astronauts probably achieved more in a few days in localised areas on the Moon than an unmanned probe would in months, for the cost of a manned trip to Mars with today's technology that could thorougly study one area you could 'pattern-bomb' Mars with a thousand or more unmanned rovers and get a good overview of the entire planet... I can't help but feel that the latter would be much better value for money.

Posted by: DonPMitchell Jul 1 2006, 08:37 PM

QUOTE (Bob Shaw @ Jul 1 2006, 04:34 AM) *
Don:

I think the mechanism for 'seeing' cosmic rays actually involves direct stimulation of the optic nerve - the eyes aren't involved at all.

It's still scary!

Bob Shaw


I think both effects exist. During the Apollo missions, flashes of light were seen, and these were explained as Cherenkov radiation in the vitreous humour. X-rays and gamma rays can also stimulate the optic nerve and brain.

Super energetic cosmic rays can cause the whole sky to flash. I don't believe the human eye can see this, but there are detectors that essentially use the night sky as a giant detector for these rare events.

Posted by: dvandorn Jul 2 2006, 01:39 AM

OK, here's a question that reveals an area of ignorance on my part...

We have a pretty decent idea of the energetic cosmic radiation levels outside of Earth's protective Van Allen belts. We also know we can see a certain number of these particles on Earth's surface itself (ever seen one of those nifty cloud scintillation chambers that were all the rage 40 years ago?), so we know that not all of these particles are shielded at the Earth's surface. (At least, when I saw one in grade school, they told me that the trails were energetic cosmic rays.)

The question is, what is the relative level of shielding provided by the Earth's magnetic field? I'm just looking for an order-of-magnitude feel for the thing -- is 1/10,000th of the unshielded flux coming through, or more, or less? That kind of thing.

-the other Doug

Posted by: DonPMitchell Jul 2 2006, 04:30 AM

Here is some information from Caltech's Space Radation Lab (where I was a grad student ages ago).

http://www.srl.caltech.edu/ACE/ASC/DATA/bibliography/ICRC2005/usa-mewaldt-RA-abs1-sh35-oral.pdf

http://www.srl.caltech.edu/personnel/dick/cos_encyc.html

Radiation is also highly concentrated within the Earth's radation belt, so the most dangerous place to be is a few hundred miles above where ISS is orbiting. In the outer belt, you would get a lethal dose or radation in a couple days.

The Earth's magnetic field looks like it may collapse for a while and possibly reverse, sometime in the next thousand years or so. The field is already about half the strength that it was during the Roman era. The Earth's atmosphere is plenty of shielding against space radiation, but I've already heard people make bizarre and dire claims about what will happen then.

Posted by: JRehling Jan 8 2008, 07:00 PM

[...]

Posted by: dvandorn Jan 10 2008, 07:54 AM

It still occurs to me that surface sample return is beyond our capabilities at the moment. Venus has a gravity field very similar to that of Earth -- you would need something more powerful than a Delta II to get a sample off the surface and into an escape trajectory, I would think (especially when you consider how much more atmospheric drag it would encounter on the way up).

That's an awfully big rocket to land on Venus and to engineer such that it will survive any sort of surface stay long enough for teleoperations.

Here's a question, though: just how valuable would a sample of Venusian air, collected at, say, 50km altitude, be? We're still above a lot of the atmosphere at 50km, right? You could design an entry probe to pump a chamber full of Venusian air (complete with dust particles, etc.), or perhaps several chambers at different altitudes. Then, when the vehicle is still moving relatively fast (we're talking Mach 6 to Mach 10 operations, here) all you would really need to boost the sample chamber(s) back to an escape trajectory would be something like one of those air-to-orbit rockets.

I'd think the data on isotope abundances and elemental compositions of dust particles would make the samples worthwhile, and you could collect such samples and then rendezvous the collection chamber(s) with a manned flyby, just as John described.

What do y'all think?

-the other Doug

Posted by: JRehling Jan 10 2008, 08:21 AM

[...]

Posted by: ugordan Jan 10 2008, 08:43 AM

QUOTE (JRehling @ Jan 10 2008, 09:21 AM) *
Launch from the surface of Venus is definitely a dicey proposition (imagine a Delta rocket descending by parachute into a 900F hell and the liquid propellant not exploding).

With the density of Venus' atmosphere, I think any rocket would have severe gravity loss penalties. You would need to avoid any significant dynamic pressure (easily builds up in Venus atmospheric density) and I think that'd actually imply subsonic velocities (and you still might have high losses due to air drag) for much of the atmospheric ride up.

How does this translate to gravity losses? If you're constrained to a velocity, your acceleration is even more constrained. The best (cheapest in terms of delta-V) way to get something into orbit is to send it up as fast as possible to minimize the time gravity decelerates you before you go on a ballistic trajectory with negligible further gravity losses. Fast accelerating rockets in other words. On Venus, your inertial acceleration would be limited to about 1 G (giving a total of about zero for early phases of flight) for a long time so the gravity losses would skyrocket. You'd need much more total delta-V imparted by the rocket than on Earth precisely because you're not allowed to accelerate fast enough in the lower atmosphere.

It begs the question if rockets can be even remotely feasible on Venus and that's even neglecting high surface temperatures and pressures and issues they cause with propellants.

Posted by: Doc Jan 10 2008, 11:15 AM

I don't know if this has already been considered but I think its worth mentioning.

Recently I had been examining atmospheric profiles of Venus and have noticed that if one were considering sending humans to the planet, it may be better to build some kind of floatable module that can hover at a certain height in the Venusian atmosphere with Terran air pressure and temperature. I can't recall how high exactly (17km?) but what I do know is that it is 'safe enough haven' for manned exploration.

Posted by: JRehling Jan 10 2008, 06:54 PM

[...]

Posted by: Greg Hullender Jan 11 2008, 12:59 AM

I like the floating base idea. Balloons, not rockets, would probably be the best way down to the surface and back up to it.

To get from the base into space, perhaps the best bet would be a rocket with some sort of lifting body so it could accelerate horizontally rather than straight up. At least you're never thrusting directly against gravity then. (And you don't need to design a rocket that'll work at 600 C). It'd need to bring its own H2 for the return flight, but the O2 could be made in situ, and that's 75% of the mass requirement.

--Greg

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