Vacumm in space and travel, spacewalking through it

When I was in high school physics, the teacher put an unfilled balloon in a dome that was sealed. She then sucked out as much air as possible. the balloon blew up like I did it outside of the vacuum. If space is such a perfect vacuum why doesn't the space craft basically blow up from the difference in pressure. You see the guys walking on the moon and their space suit don't seem to be all puffy even though they are full of oxygen to breathe. I would think these thing would blow up like a balloon in physics class. Especially since the physics class vacuum wasn't even close to total emptiness.

The spacecraft and space suit seem to have greater structural integrity than the rubber balloon.

Almost like they where designed to handle the difference in pressure so they don't explode killing everyone.


a reply to: jlafleur02

originally posted by: jlafleur02
When I was in high school physics, the teacher put an unfilled balloon in a dome that was sealed. She then sucked out as much air as possible. the balloon blew up like I did it outside of the vacuum. If space is such a perfect vacuum why doesn't the space craft basically blow up from the difference in pressure. You see the guys walking on the moon and their space suit don't seem to be all puffy even though they are full of oxygen to breathe. I would think these thing would blow up like a balloon in physics class. Especially since the physics class vacuum wasn't even close to total emptiness.

Because in space, the vacuum is already present, where as in the jar example, the balloon went from no vacuum to vacuum

a reply to: jlafleur02

What Athetos said:

Almost like they where designed to handle the difference in pressure so they don't explode killing everyone.

Here's a picture of an Apollo Lunar Module with its outer covers off:

Note the aluminum framing on the outside of the skin. Apollo spacecraft were only pressurized to to 5 pounds per square inch (straight oxygen), which is less of a pressure differential than a typical passenger aircraft deals with at 35,000 feet. Soyuz, Shenzhou, the Space Shuttle and most space stations use a standard nitrogen-oxygen mix at 14 lbs psi, so they are built more robustly.

Similarly, spacesuits are made with many layers which include an inner pressure layer to hold in the air (oxygen at ~3.8 lbs psi), thermal insulation layers, and tough outer layers to protect against cuts, chafing and micrometeors. Between the pressure layer and the thermal insulation is a restraint layer - basically a nylon mesh - that is there specifically to keep the pressure layer from ballooning in vacuum.

Hope this helps.

a reply to: jlafleur02

When the balloon was placed inside the vessel, had the balloon’s end been “tied off” or otherwise clamped to prevent the air already inside the balloon from being evacuated when the air in the vessel was sucked out?

If it was tied or clamped, that’s why the balloon expanded in vacuum; there was still air in the balloon to expand under the low pressure of the vacuum.

As to why spacesuits and spacecraft “don’t” expand;

Well, actually they do.

As explained above, they are designed to resist expansion in a vacuum environment, but they still do expand. But again, as explained previously, the materials they are made of limit the amount of expansion.

Thing is though, if you read up on the history of spacesuit design, and especially the EVA (Extra-Vehicular Activity) suits worn by the astronauts who walked in the Moon, you find out that they were so bulky and “ballooned” so much that it made doing anything on the Moon extremely difficult.

originally posted by: jlafleur02
You see the guys walking on the moon and their space suit don't seem to be all puffy even though they are full of oxygen to breathe.

The white outer layering of the spacesuit is just that -- an outer layering.

The spacesuit has many other layers that keep it pressurized. Some of those layers are structurally stronger than the inside air pressure, and that's why they don't inflate like a balloon. A balloon's elasticity cannot counteract the air pressure from being blown up, and that's why it expands/inflates under pressure.

airandspace.si.edu...

a reply to: jlafleur02

I did not go through the replies in this thread but am sure someone mentioned it already... Their suits didn't blow like a michelin dude because they never went. As for all spacewalks... there was probably one trying to walk in space and died. We do not have the technology... simple as that.

I came to this conclusion after seeing those astronauts playing like little children on the moon while the rapture of one stitch could end their lives... No, if you are aware of how dangerous this environment is you would be very careful with your moves.

the rapture of one stitch could end their lives

More than one layer ... do read the thread.

The sips are pressurized vessels built for vacuum environment and the suits are built for vacuum environment as well.

Space suits are several layers both to prevent expansion and redundancy in case of an accidental breach during use. They are probably bulletproof.

to see the pic below you need to use the white screen.

originally posted by: zatara
like little children on the moon while the rapture of one stitch could end their lives...

Good thing they're already in space then, don't have as far to fly up to heaven.

a reply to: zatara

I am amazed that the space agencies aren't beating a path to your door to take advantage of your in-depth knowledge and understanding.

The suits didn't blow up like a Michelin dude because the bit you see isn't the pressurised bit, just like the bit you see getting covered in dust and scratches on the moon isn't the pressurised bit, it's designed to protect it against dust and scratches.

No-one has died in a spacewalk, though a few have found out how difficult it can be to do things when you are in an over-pressurised suit.

Actually the first cosmonaut (Russian) that did a spacewalk had a lot of trouble getting back inside the spaceship cause his suit had expanded more than planned....

I can't believe how stupid people are.
Car tires don't blow up like balloons is because they have nylon cord and steel belts inside the rubber.
U.S space suits work with just over 5 psi of O2.

Besides this vacuum of space everyone is freaking out about is only 14.7 psi less than earth at sea level.

sniff sniff

ah yes, another thinly veiled flat earth dome thread

Having said all that (what the others posted above me), there is a certain amount of "ballooning" that happens to a space suit in vaccum, which is why spacewalkers only use Oxygen in their suits, at 20% of atmospheric pressure. That way, they get all the oxygen they need, and the spacesuit doesn't inflate as much. er.jsc.nasa.gov...

a reply to: jlafleur02
If you have about 3/4 of an hour, there's a fantastic documentary on how difficult it was to make a space suit. NASA was beyond their expertise and ended up contracting out the project to a leading bra maker who knew how to make flexible garments, who sent samples to NASA for rigorous testing.



The funniest part of that video was how the astronauts could pee inside the suit using a condom attached to a bag, but the condoms were falling off some astronauts in testing because of the small medium and large sizes, nobody would use a medium or small condom. To solve the problem, they re-named the three condom sizes to large, gigantic, and humongous, and after that they could get the astronauts to use condoms that fit, since the smallest they had to choose from was "large", and they were OK with using that if it fit.

bout time ya laid it out so well.....on why the suits don't puff up....thanks....

Since the glass in the helmet seemed adequate, why not make the whole suit out of glass? No layers needed.

a reply to: jlafleur02 Here is another question. How can you have a vacuum in space? Vacuums occur in enclosed spaces. Space is not enclosed, not according to the big bang theory,anyway.

originally posted by: TamtammyMacx
Since the glass in the helmet seemed adequate, why not make the whole suit out of glass? No layers needed.

They don't need to see out of the entire suit so no reason to use transparent material in places other than the visor. They did try "hard suits" as seen in the video I posted a few posts ago, but they were too bulky. Here are some examples:

originally posted by: pointessa
a reply to: jlafleur02 Here is another question. How can you have a vacuum in space? Vacuums occur in enclosed spaces. Space is not enclosed, not according to the big bang theory,anyway.

That's like asking "Cars are red, so how can there be black cars?"

Yes, some cars are red, but that doesn't mean all cars are red.
Likewise, some vacuums occur in closed spaces, but that doesn't mean all vacuums occur in closed spaces.

Vacuum is a relative term anyway, even the deepest space probably has an atom of hydrogen per cubic meter thus is not completely empty, though pretty close.