Shooting stuff into space because it is cool and maybe send supplies up there.

[HOZ]

Very cool

This brings new meaning to shooting off your back porch!

How to Shoot Stuff into Space

STEP 1: HEAT IT
The gun combusts natural gas in a heat exchanger within a
chamber of hydrogen gas, heating the hydrogen to 2,600˚F and causing a 500 percent increase in pressure.
STEP 2: LET THE HYDROGEN LOOSE
Operators open the valve, and the hot, pressurized hydrogen quickly expands down the tube, pushing the payload forward.
STEP 3: TO INFINITY AND BEYOND
After speeding down the 3,300-foot-long barrel, the projectile shoots out of the gun at 13,000 mph. An iris at the end of the gun closes, capturing the hydrogen gas to use again.

[BlackArcher101]

I fail to see how it doesn't lose hydrogen gas each time it shoots?

[HelloHockeyFans]

Littering for fun!

[SebC]

Originally Posted by BlackArcher101

I fail to see how it doesn't lose hydrogen gas each time it shoots?

Well, they could do it by putting the payload on time of a piston sort of thing that seals the hydrogen. Of course, then they'd have to be able to decelerate the piston from 13,000 mph to 0.

More likely the payload is the piston. All the hydrogen would be behind the payload, they'd just need to stop the flow after the payload is out the tube. Valve needs to close fast, but it doesn't have to open right when the projectile arrrives. When the projectile arrives at the end of the gun, the hydrogen would be decompressed a lot and decompression also cools it. Acceleration would be maxed out when the release valve opens, and decrease from there on out. Even if it does leak a bit, given the high cost of launching stuff into space, you could just make hydrogen to replace the losses and it would still be worth it.

[icarus]

But is it more cool or less cool than a space elevator: http://en.wikipedia.org/wiki/Space_elevator ?

[HOZ]

/\/\/\/\ Cannon vs elevator......no contest

[Rathji]

Originally Posted by HOZ

/\/\/\/\ Cannon vs elevator......no contest

Yeah, I wouldn't ride an elevator if I could go in a cannon either.

[Dan02]

I only see a couple small problems,

firstly, the G forces involved to speed something up that fast in such a short period of time is just massive. Someone calculate in the comments that its north of 1700Gs, whether that number is true or not I can't say but either way I'm pretty sure anything you'd want to launch up there wouldn't make it out of the tube in one piece.

And secondly, if the space shuttle burns up at roughly that speed in the upper atmosphere where there's relatively little drag, if you launched something at sea level wouldn't it pretty much end up as a giant flaming fireball?

I've though about like this in the past and it seems to me firstly you're going to need MUCH longer acceleration period, and you're going to need to release the launch vehicle at a significantly higher altitude, say top of really tall mountain. Maybe I'm just unlearned but this guys idea seems to be a pretty poorly thought out and full of fail.

[HOZ]

Originally Posted by Dan02

. Maybe I'm just unlearned but this guys idea seems to be a pretty poorly thought out and full of fail.

Pfft! As if that ever stopped people from trying. I mean the hours and hours of fun, shooting great big balls of fire into orbit truly outweighs the fail factor here.

[Knalus]

Originally Posted by Dan02

Maybe I'm just unlearned but this guys idea seems to be a pretty poorly thought out and full of fail.

The only reason this idea hasn't progressed to the point we are using it all the time now, is because man's first few steps into space were during the cold war, and a large piece of artillery like that was worrisome, and therefore banned by treaty (the Russians were scared of the Shuttle, for goodness sakes, thought it was supposed to be a bomber). The idea of firing a cannon into space is older than rockets, cheaper than rockets, and should be done. Nothing new here. Except for hanging it underwater for support - never heard of that idea before. That's a good idea.