[X] My Assistant

[Rem31]

Can you walk on Mars (without) protection spacesuit? I think it is possible because it is only my thought. Is this true?

[Guest_BruceMoomaw_*]

No. Before 1964, it was thought that this would be possible -- but in that year, ground-based measurements indicated that Mars' surface air pressure was less than 1% of Earth's (less than 1/10 of what it had previously been thought to be) -- and the next year Mariner 4 solidly confirmed this. It is impossible for a human to maintain consciousness in such a near-space environment without a full-scale pressure suit.

[mcaplinger]

Not currently, no. But I feel compelled to mention that in the 24-hour media blitz following the publication of "Observational Evidence for an Active Surface Reservoir of Solid Carbon Dioxide on Mars" by Malin et al, I made a remark to abcnews.com which they reported thusly:

Michael Caplinger of San Diego's Malin Space Science Systems points out that if the warming were to continue at the same rate (that's a big "if"), Mars could become a nearly inhabitable place for people within 5,000 years or so.

"Rather than wearing a spacesuit, you could get away with wearing just an oxygen mask and a thick parka," said Caplinger, who co-authored a study about the observations in this week's issue of Science. "It would be like standing on top of Everest."

--------------------

Well, OK, I said it, and the person from abcnews.com did the best job by far of reporting the story, but it wouldn't be that much like standing on Everest. If the atmospheric pressure went up 10X to, say,
60-90 millibars, that's still about 4-5 times thinner than the summit of Everest (which is at about 320 millibars.)

It's an interesting question if you could avoid skin hemorrhaging at this pressure. Would a spandex bodysuit under your parka be enough?

[Guest_BillyMER_*]

Not currently, no. But I feel compelled to mention that in the 24-hour media blitz following the publication of "Observational Evidence for an Active Surface Reservoir of Solid Carbon Dioxide on Mars" by Malin et al, I made a remark to abcnews.com which they reported thusly:

Michael Caplinger of San Diego's Malin Space Science Systems points out that if the warming were to continue at the same rate (that's a big "if"), Mars could become a nearly inhabitable place for people within 5,000 years or so.

"Rather than wearing a spacesuit, you could get away with wearing just an oxygen mask and a thick parka," said Caplinger, who co-authored a study about the observations in this week's issue of Science. "It would be like standing on top of Everest."

--------------------

Well, OK, I said it, and the person from abcnews.com did the best job by far of reporting the story, but it wouldn't be that much like standing on Everest. If the atmospheric pressure went up 10X to, say,
60-90 millibars, that's still about 4-5 times thinner than the summit of Everest (which is at about 320 millibars.)

It's an interesting question if you could avoid skin hemorrhaging at this pressure. Would a spandex bodysuit under your parka be enough?

I think you could possibly get some opposition about getting by with just an oxygen mask,like what is success in these circumstances,living for 10 seconds ? :-)

How about deep underground on Mars in a cavity you filled would with oxygen to over come the pressure problem ? That would be an experience to take the first breath on another planet un-aided and smell the aroma of another planets soil even though it not on the surface.

[Bob Shaw]

Mike:

There *have* been interesting experiments with Spandex-like garments as spacesuits (and no, I don't refer here to any UK Conservative MPS and their, ahem, 'hobbies'). The problem is not so much with your body as your head. The human body isn't likely to go bang as such if exposed to low pressures, but you are talking about bleeding and bursting problems at the head end of things (let's leave the bottom end out of this at the moment!). Another problem relates to the direction that oxygen will flow - it'll pass from the blood to the lungs at very low pressures, and you'd become unconscious even though nominally hyper-oxygenated. But, if you can keep the upper body properly sealed, the rest of the body is quite resilient - Spandex and a vapour barrier might well be enough. It does, however, all sound pretty uncomfortable! Temperature control might be fun, too...

Perhaps these sorts of technologies would be more appropriate in agricultural habitats on Mars, where you would have an unbreathable atmosphere of CO2 at (to you and I) low pressures. Such buildings, domes, tents or whatever might well be unsafe to work in without some sort of emergency personal life support (think of a yachtsman's life vest - just enough to get you to safety).

Titan, though...

Bob Shaw

[edstrick]

Open the Pod Bay door, please, Hal....

[mcaplinger]

There *have* been interesting experiments with Spandex-like garments as spacesuits...

Yes, I'm aware of those. But to clarify, I wasn't talking about current martian conditions, where clearly full spacesuits are required, I was talking about a hypothetical situation where the pressure had increased 10x to about 100 mbars. If I'm doing the calculations correctly, that's equivalent to an altitude on Earth of about 17 km or 56,000 feet. That's in the gray area of maybe not needing a full pressure suit -- see http://www.nasa.gov/centers/dryden/researc...ER-2/pshis.html

My thinking was clearly prejudiced by this quote from Heinlein's RED PLANET (1949):

"the colonials maintained about two-thirds Earth-normal pressure indoors for comfort and the pressure on Mars is never as much as half of that... Among the colonials only Tibetans and Bolivian Indians will venture outdoors without respirators and even they will wear the snug elastic Mars suits to avoid skin hemorrhages."

Of course on Heinlein's Mars there was enough oxygen in the atmosphere to be used after compression by his respirators. I assumed pure CO2, and I was off on the pressure by 3x, but it made good copy.

[ljk4-1]

But former US VP Dan Quayle said that Mars has canals, oxygen,
and water - so why shouldn't we be able to walk around on Mars
free as can please?!

http://www.quotationspage.com/quote/526.html

Our politicians know all; they'd never lie to us.

[tty]

But former US VP Dan Quayle said that Mars has canals, oxygen,
and water - so why shouldn't we be able to walk around on Mars
free as can please?!

http://www.quotationspage.com/quote/526.html

Our politicians know all; they'd never lie to us.

I think it was H. L. Mencken who when asked what a tautology is, explained that it means saying the same thing twice, for example "ignorant politician".

tty

[Bill Harris]

Full pressure suits... gone are the days of the innocence of youth.

Years ago one of the hot discussion topics was terr@forming Mars. Is that even a serious topic of nowadays? Besides the formidable task of importing an atmosphere and hydrosphere, can you imagine the chemical reactions that would take place and the amount of time it would take for the planet tosettle into equilibrium conditions?

--Bill

[Bob Shaw]

Full pressure suits... gone are the days of the innocence of youth.

Years ago one of the hot discussion topics was terr@forming Mars. Is that even a serious topic of nowadays? Besides the formidable task of importing an atmosphere and hydrosphere, can you imagine the chemical reactions that would take place and the amount of time it would take for the planet tosettle into equilibrium conditions?

--Bill

Bill:

Over Geological Time, it could be done in the blink of an eye and for minute cost; over Political Time, it'd take an infinite time, and cost at least as many $ (double that if an international effort!). Still, doubling something that's greater than infinity really leaves you with infinity, so that'd be a cost saving, I think. Let's see: potatoe. Yup, sounds right...

Bob Shaw

[Guest_BruceMoomaw_*]

Don't forget that the ultimate culmination of Kim Steanley Robinson's Mars Terraform epic -- after "Blue Mars" -- is the collection of short stories that might be called "White Mars", in which the process goes wrong and refreezes the planet (albeit with a thick atmosphere this time). At the end of that book, they're still trying to figure out how to straighten out the mess again.

[Bill Harris]

After I posted my earlier message I googled terraforming and came up with many hits; I'd say that it may still be a hot topic. However, with today's greater environmental/Green awareness I suppose most would be less hesitant to do that. Recall the agricutural experiment that terraformed the Aral Sea into a playa...

--Bill

[Rem31]

After I posted my earlier message I googled terraforming and came up with many hits; I'd say that it may still be a hot topic. However, with today's greater environmental/Green awareness I suppose most would be less hesitant to do that. Recall the agricutural experiment that terraformed the Aral Sea into a playa...

--Bill

What do i experience when i get out of my (hypothetical) Marslander (without) space(pressure)suit ,and only with my trouser and a t shirt or sweater and step on the Mars surface and begin to walk? Do i survive it?

[Bob Shaw]

What do i experience when i get out of my (hypothetical) Marslander (without) space(pressure)suit ,and only with my trouser and a t shirt or sweater and step on the Mars surface and begin to walk? Do i survive it?

Well...

...depending on the circumstances before you get out (pressure, oxygen content in the air within the lander), and assuming you remember to SCREAM to equalise pressure (just like submariners exiting their stranded vehicles are instructed to do), you might be conscious, but none to happy, for 30 seconds or so. You're unlikely to go bang, and you might well be reviveable for a few minutes after that, but with a massive lung oedema, likely leading to early death. 2001-style *brief* exposure to near zero pressure is no problem, but shut that door ASAP!

Speaking of doors, if experience on the Moon is anything to go by, it may take ages to decompress the cabin enough to open the door, in which case you'll have passed out before leaving the spacecraft.

Unsuited sprints on Mars bases from big, fast-opening airlocks to other, fast-closing ones are actually quite feasible, and could be great fun, unless they are not fun, in which case they'd be verrrrry little fun at all!

Oh, for Kemlo when you need him!

Bob Shaw