Not a problem at all. Better one answer too many than not enough

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Well, the success of the Apollo missions suggests that building a pressure vessel that can survive in space and be landed seems to be a solved problem....

Umm, nope. A spacecraft internal pressure is 15psi, end of story. They don't pressurise them to 15psi over atmospheric pressure on Earth and then launch them into space. The pressure difference across the hull is zero on Earth and 15psi in space.

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"The very powerful and the very stupid have one thing in common: They don't alter their views to fit the facts, they alter the facts to fit their views." The Doctor, Doctor Who: The Face of Evil.

Thank you for clearing that up....14.7psig is 14.7psi inside the spacecraft.

Other quick questions if I may:

Temp/climate in space ? Orbit? Outer Space?

How is radiation shielding handled?

1 ATA is not that great of a pressure change. I can hold my finger over a leak comming from a 2 ATA vessel and stop it.

Hi Jason, I hope you don't think and advanced colony on another planet is going to "live" in something the size of apollo!!! Have you any idea how much room it takes to hold all of the equipment it takes to sustian life, make food, recycle atmosphere, repair parts,communications, and then accommodate people for a "Very extended time"???????????????????????????? We are a long,long,long so very long way from star trek.
So lets try to grasp reality. Could you and 20 people live in an elevator for 20 years? Many people can't hack life on a submarine...for even a short time.
I applaude your enthusiasm. Look at the facts.
Best regards,
Dan

Of course I don't. My point was that making a pressurised landing craft was not the most challenging aspect of that project, so I don't see why it should become so by the time we get to colonising other planets.

Yes thank you.

I have looked at the facts, thank you.

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"The very powerful and the very stupid have one thing in common: They don't alter their views to fit the facts, they alter the facts to fit their views." The Doctor, Doctor Who: The Face of Evil.

I'd expect such a colony to be far larger. Why wouldn't it be?

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Disclaimer: Avatar is not an official NASA image and does not imply any specific interplanetary or interstellar capability.

The Leif Ericson Cruiser

I'm not convinced the 4.7 psi figure is correct. The suit can hold that pressure, but I think the normal pressure is 4.3.

Astronauts always do some time breathing pure oxygen before getting into the suits, even the higher pressure Orlon suits.

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Disclaimer: Avatar is not an official NASA image and does not imply any specific interplanetary or interstellar capability.

The Leif Ericson Cruiser

Dan, to be fair, the scope of the problem wasn't previously defined.

Skylab is a better example of a fairly large module that can hold the pressures with no problem. From an engineering perspective it is not that difficult to build a fairly large structure that has a positive pressure, it is much harder to build a structure that has a negative pressure. To compare a spaceship with a submarine from an engineering perspective is like comparing a fish to a swallow, they are completely different animals, designed in different ways to cope with completely different environments.

I don't think anyone would consider one enormous module that everyone would live in, I think it would be broken down into smaller modules with pressure doors, each module would be quite capable of withholding such a small pressure difference. Each module would be a working area or even a living quarter, each module would be a self contained living unit if required allowing privacy.

Come to think of it, it would be almost exactly like what we have on Earth right now.

The social argument is not really valid either. Arguments will happen, but people can live in close proximity and not destroy each other or go mad.

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"If you've made it to retirement without being blamed for a major disaster, you've failed as an engineer."

Would anyone care to comment about climate/temp in space.???

If a human being was suddenly exposed to deep space without a spacesuit, how do you think he would die ?

Well he would not freeze, because there are very few atoms to take the heat away from his body, he would get cold eventually over a long period of time, but he certainly would not freeze, even in shade. In fact, he would barely feel any cold at all.
Apollo 13 was a good example, with no power and no heating after several days, it was cold yes, but it was not cold enough to kill them.

His blood would not boil and his eyeballs would not explode either, contrary to what you see in films. Blood pressure is simply far too high and the body is a very good pressure suit to start off with for that to happen. He would have serous problems yes, but this would not kill him.

In fact, provided he exhaled his breath first, he would simply asphyxiate. If he didn't exhale his breath, his lungs would explode terminating the experiment early.

Even though deep space is close to absolute zero, because there are so few atoms to take away the thermal energy it is very easy to stay warm, it is keeping cool in space that is the big problem.

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"If you've made it to retirement without being blamed for a major disaster, you've failed as an engineer."

Hi, Have you ever in your young life opened a bottle of champagne or
ginger ale? Next time look at it while you do this. Shake it first, maybe.
There is air in solution in your bloodstream. Complications arise from a vaccuum . It's a long story.
The process may be a bit slower than hollywood describes, but a process never the less.
And when a compartment depressurises quickly, the atmosphere left within cools down muy pronto (very quickly) ...Boyle's Law.
How would this happen? Meter strike? Space junk strike? Ice particle stricke?
We just don't know how much is in free space at some relative velocity.
But look up on a clear night....late..., and watch these little gems streak across the night sky at ...say 25,000 MPH ...and faster. Much faster than anything out of a rifle. That is your problem ...in space and on some far off planet with less than an atmosphere. So that tin foil wonder that landed on the Moon ( and we all give those brave men and the engineers that designed and built apollo high praise ) is a big gamble. A very big gamble. They did it to prove a point. They succeeded. But...some people want to live there.
How will you deal with space on a longer time scale?
Even a BB at those speeds will ruin your whole day.
Just something to consider. There is much to consider in the vaccuum of space.
Best regards,
Dan

Atmosphere left within ??

Dan, do not confuse the bends (coming up from a deep sea dive) with this question, a pressure change of 1 atmosphere is not enough to induce the bends to that extent, although some gasses may be released into the bloodstream it would in fact feel like a very mild case of the bends and certainly not like a pop bottle exploding.

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"If you've made it to retirement without being blamed for a major disaster, you've failed as an engineer."

No...it can be serious... "bends" is a general term used for several types of decompresion sickness. The rapid decompresion from 1 ATA to O after long term saturation at 14.7 psi can really create several problems.

I agree. And I am a qualified diver. We value our lives and respect
air. No question.
Best regards,
Dan

Yes, as you can see when you actually read my post I have already said that he would have serious problems, but it would not kill him.

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"If you've made it to retirement without being blamed for a major disaster, you've failed as an engineer."

Please "my young life"...????
My recent questions are on temp/climate of space.

A lesson in decompression sickness and Boyles Law was not what I was asking for as I am an expert on this.

I will try to be more clear:

How hot or cold is it in Near Earth Orbit?

What are the characteristics of the object you are asking about and is it in direct sunlight or not? Temperature is a property of matter and even in NEO there isn't enough matter in space to give a meaningful temperature.

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My apologies.....

I was wondering about climate control of both spacesuit and spacecraft.
What would be needed due to temp. In NEO?? I would imagine the suit itself would have an insulating factor that required compansation.

In U/W construction we use hot water systems pumped into special suits.
In addition, the use if certain inert gasses can cause the body to lose heat quicker than normal. My gas & pressure questions have been answered already and need to understand climate control before I "take off".

Don't Panic.....I won't forget my towel.

Atoms to take away thermal energy........Hmmm...This helps my understanding.

Thank You.

Hi, That would be a function of radiation, and not a function of heat delivery in a medium. If you are in shade, you're cold....very cold.
If you are in the glare of the Sun, you will get Hot. N'est pas?
Best regards,Sir.

I was interested in this myself. Started a thread on spaceship colour. Basically in a near Earth environment, it's all about the Sun. It's hard to cool down quickly, so parts that are exposed to the Sun get hot fast. Conversely, parts that are in the shade for an appreciable amount of time, eventually get very cold. Sorry, I can't give you exact temperatures- but the NASA ISS pages may help you.

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Thermal conduction. Without material in contact with something warm or cold, temperature differences can only be equalized by thermal radiation.

I performed an experiment one time where I put scalding-hot water into a vacuum flask (thermos) and left it for about 23 hours. The water was still too hot to comfortably pour onto my hands after that time.

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As others have said, it's not really a simple question. You can't think of temperature in space the same way as temperature on the earth. Mostly on the earth we are affected by the temperature of the air that surrounds us. So even at night, it's fairly warm. But in a near vacuum, there is no medium to keep the temperature, so it is purely a question of whether the sunlight is striking you. In the sun, you will be very, very hot. And in the shade, you will be very, very cold. In orbit, you normally spend half the time in the sun and half in the shade, so you will alternate. I'm not an expert but my understanding is that the heat will only radiate away from you very slowly, so you will end up overheating in orbit. That's why the space shuttle has a big radiator to dissipate heat.

Here is a good elementary article on the subject.

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One point to add to this: no one wants to discover upon reaching orbit that the hatch isn't quite closed, so to check for leaks, spacecraft are slightly pressurized once the astronauts are sealed inside, then vented to return the cabin to ambient pressure before launch. The leak check doesn't require a huge overpressure; for the Shuttle it's only 2 psig.

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“There’s nothing that spells progress in large, friendly letters like trying to combine two totally incompatible technologies.” – David Szondy, Tales of Future Past.

But it's a *near* vacuum, which means there is stuff. What is the temperature of the interplanetary medium? Anyone know?

Amber Robot. That'd be the temperature of the solar wind that blows around us on it's way out of the solar system. The slow wind ~160,000 K, and when it's the fast wind, ~ 800,000 K. see:http://en.wikipedia.org/wiki/Solar_wind

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