If I were going to test my spaceship....

Just curious, I don't really have a spaceship. But if I was going to test it out before its maiden voyage, how much pressure would I need inside the cabin to simulate the forces acting on the hull in the vacuum of outer space?

It's always been a dream of mine to build a ship and fly around, visit the planets, etc. When I'm doing something monotonous my mind wanders and I go back to designing my space ship. Every time I get to testing the hull, I draw a blank in the "how much pressure" area.
I seem to remember something from waaay back in high school about the average pressure on earth is around 15 psi. Does that mean I would need 15 psi inside the hull on earth to simulate the forces in space?

p.s. No need to destroy my dream, I know it's only a dream. I'm just trying to be realistic about this dream. (did that make sense? probably not,,,lol)

Let's take this a step farther, tell me about your spaceship. How does it operate? How do you recycle your air? Water?
Could be fun, use your imagination.
I'll give my details in a while, maybe in the morning. I haven't written any of my details down, it's all in my head at the moment.

Originally posted by Beer_Guy
Just curious, I don't really have a spaceship. But if I was going to test it out before its maiden voyage, how much pressure would I need inside the cabin to simulate the forces acting on the hull in the vacuum of outer space?

It's always been a dream of mine to build a ship and fly around, visit the planets, etc. When I'm doing something monotonous my mind wanders and I go back to designing my space ship. Every time I get to testing the hull, I draw a blank in the "how much pressure" area.
I seem to remember something from waaay back in high school about the average pressure on earth is around 15 psi. Does that mean I would need 15 psi inside the hull on earth to simulate the forces in space?

p.s. No need to destroy my dream, I know it's only a dream. I'm just trying to be realistic about this dream. (did that make sense? probably not,,,lol)

"Space" is a vaccum so you would need to test your spaceship by pressurizing the cabin to equal the forces the spaceship would encounter if it were in a vaccuum.

If you were performing these tests at sea level you would first need to equalize the pressure inside the ship to offset the atmospheric pressure pressing on the outside of the craft; as you have said, that's about 15psi.

Then, you would need to Add pressure to equal the atmosphere you intend to employ while operating the ship in space, that might be a little as 8psi, up to as much as one full atmosphere, 14.7psi.

So as you can see, you would need to pressurize your spaceship's hull to somewhere roughly between 21-30psi to thoroughly check it out.

Watch out for leaks. And if anyone is inside the craft during the test, take precautions against the "bends" resulting from too rapid de-pressurization!

I'd advise talking to someone with deep diving experience BEFORE attempting a "live" test.

In most early ships, they only pressurized the capsule to around 5.5 psi of pure oxygen, since that's the partial pressure of oxygen here on Earth. Doing that significantly lowers the stress on the hull.

Wow, 30 psi would be like the inside of a car tire. I wonder if there would be any long term effects from that.
Since I started this project back when I was a teenager, I "knew" that I would have developed an anti-gravity device that would make the ship weightless no matter what it was made of. (no cigar yet on that one ) So I decided it would be made of 1/4 inch plate steel reenforced with "ribs" of 1/4 inch plate steel with every seam welded on both sides. I think that would let it endure hundreds of pounds of pressure (I like overkill). I didn't want to be up in space sitting inside a soda can, therefore, no aluminum.
Do you think lead crystal glass would make good windows? Does it have enough lead in it to keep out the radiation?
I have some ideas using algae and other plants to recycle air and water, but that's a little sketchy too.

consider that the pressure in the vacuum of space is about 0 atm, and in anycase you would need no more and no less than about 1 atm inside the cabin.

consider that the pressure in the vacuum of space is about 0 atm, and in anycase you would need no more and no less than about 1 atm inside the cabin.

In different words, that's exactly what I said.

what about hydro-ponics (phenetic spelling, it's great, I can spell)
I forgot if they already had a lab on the space station already.

Yep, they've done hydroponics(you spelled it right) in space. Space makes it a bit more difficult though because of the lack of gravity. It is definitely something I would try to work out on my spaceship. I'd get fresh tomatoes and oxygen.

Shouldn't have to double the pressure inside the cabin. It's at 15psi already. You just have to increase it so your guage, which is calibrated to normal atmospheric, reads 15psi and that will effectively simulate a vacuum.

Hydroponics in space hmm... aeroponic would probably work. Ebb and flow or water cultures wouldn't.