Secrets of the Mystery Gun that Shelled Paris

http://blog.modernmechanix.com/2008/10/09/secrets-of-the-mystery-gun-that-shelled-paris/?Qwd=./ModernMechanix/6-1930/paris_gun&Qif=paris_gun_0.jpg&Qiv=thumbs&Qis=XL#qdig

by boundlessdreamz • 17 years ago

50 33 17 years ago

blog.modernmechanix.com

pg5• 17 years ago

Sputnik's perigee was only about 155 miles. Could this gun have shot a shell into orbit if they'd made it sufficiently light?

DanielBMarkham3• 17 years ago

I programmed a simulator that asked this very question a few years back just for kicks. I was wondering what types of things might help us reach low earth orbit on the cheap.

The answer is no -- any kind of ballistic shot needs some kind of tangential thrust applied at some point to achieve orbit.

You can shoot something really far with a cannon and still it hits the ground. It's possible to shoot and hit things on the other side of the earth like this, but you're going to have a huge apogee!

pg5• 17 years ago

Any kind of ballistic shot? That doesn't seem right. If you can make the initial impetus arbitrarily powerful and the projectile arbitrarily light, surely at some point you cross the threshold of being able to get it into orbit.

celoyd2• 17 years ago

Probably not, no. The biggest guns (see Wikipedia on Project HARP) can get a payload to 100 mi, but we can't yet combine that with the horizontal speed necessary to orbit. The problem (I gather) is the atmosphere. Sputnik was traveling along its orbit at about 18k kph, 10 times the velocity quoted for this shell, or about Mach 25 at sea level. Your muzzle velocity will have to be much higher to get it outside the atmosphere going that fast, and the shell will have to withstand ~30 seconds of shuttle-reentry-like heating and buffeting.

Possible, definitely, but not with this gun.

pg5• 17 years ago

Is there some practical limit to the muzzle velocity of a gun?

ivankirigin6• 17 years ago

The issue with a gun to get things into orbit is that you need to provide enough force right at the beginning to get into space. That would destroy most anything. So you could shoot something into orbit, but it will be a largely mangled hunk of metal by the end of it.

If I were in 1910, trying to get something into space, I'd use a hot air balloon to go a few miles, then shoot a gun. Ideally, it would be done at the equator, where the tangential speeds are higher and getting into orbit is easier.

pg5• 17 years ago

We can deal with mangled hunk of metal problem in version 2. For now I'm just asking whether one could get anything into orbit by shooting it from this gun.

jacquesm• 17 years ago

Hard to deal with recoil issues when firing from something that is not anchored. You'd have to have a pretty massive balloon.

billswift2• 17 years ago

The fundamental problem is that even with enough velocity, and it would need to be substantially higher than even the Paris gun's, is the need to circularize the orbit, otherwise it will just dive back down to ground level on the other side of the Earth.

yread2• 17 years ago

Be sure to read -DOUG-'s comment at the end of the article!

dangoldin• 17 years ago

There's some more information here too: http://en.wikipedia.org/wiki/Paris_Gun

movix• 17 years ago

I was snooping around that web site after reading the fascinating article, and found this article in the 'Scary' section. Food for thought no?

http://blog.modernmechanix.com/2008/06/05/the-computer-data-...

pj• 17 years ago

I love reading about the historical future of technology. Post it and I'll vote it up!

Secrets of the Mystery Gun that Shelled Paris

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