the earth? If so have we ever shot anything in this manner that totally escaped the gravity well of the earth?
Nope. Escape velocity (the velocity you need in order to escape from the Earth’s gravity) is huge on the surface of the Earth, and is much much bigger when you consider that the atmosphere will eat up a lot of your energy in drag and that the rate at which you will lose this energy will go up as the square of your velocity.
no.
But if it hadn’t been for Mossad, Iraq might very well have been the first.
The escape velocity is the speed at which an object must accelerate to in order to completely leave the Earth’s gravity well and never return. This is about 25,000 MPH or over 30 times the speed of sound at sea level. We’ve never come closer to this with a ballistic projectile. However, just to get into space (depending on your definition of where “space” begins) doesn’t require anything near escape velocity, though, of course, the projectile will eventually fall back down to Earth. Gerald Bull’s supergun, as described in Tuckerfan’s link, might have done the job:
One could argue that such a projectile could be said to have “entered space”.
Nah. That thing would have been sub-orbital.
To address the OP, it depends on what you mean by "shot.’ We’ve launched plenty of things that are destined for cold oblivion, but we expected them to do things for us along the way out. We’re still doing that, and we still call each launch a “shot.”
If you mean “shot” to be “shooting something into a stable orbit from some sort of sea-level cannon-type apparatus,” then no,we haven’t done that. Are you talking orbit or escape velocity?
We probably could reach escape velocity (been there, done that, see above) with current technology, assuming we’re just shooting the thing and the payload wouldn’t include any electronics, because the initial acceleration within a gun tube (massive) would be far outside anything we could buffer our currently-avalable circuits for. W
The problem with non-rocket-based launching systems is taht you have to climb the gradient. Guns judt don’t
Livermore’s Super High Altitude Research Project (SHARP) project achieved 3 km/sec with a 5 kg projectile. They were planning to raise the barrel and up speed to 7 km/sec when they lost funding in 93.
Yes, I know. My quoted portion stated as much, did it not? However, “shooting something into space” doesn’t necessarily mean “putting it into orbit”. The borderline between Earth’s atmosphere and space is fuzzy at best, so my point was you could almost certainly stretch some definition of where space begins enough to say a projectile that attained an altitude of 180 km “entered space”.
Just to clarify, it’s mathematicly impossible to launch an unpowered projectile into orbit. You need to add some power when the projectile is in the orbit path to keep it there.
I don’t know what happened there.
I’m just going to make my points and leave:
Guns: High acceleration, short time.
Rockets: Low acceleration, long time.
And that’s all relative. The point I was trying to make was that you could “shoot” something into orbit or “out,” but your payload would be useless.
Sorry, I’m an idiot. You can ignore my subsequnt posts too. unless you want to rub it in.
Nah, you’ve got a good point about payload survivability. A gun is a lousy way to get electronics into orbit, and would be rather messy for humans. Still, I think if we wanted to we could get a hunk of metal into orbit. For what purpose, I couldn’t say.
I can’t find any on-line pics of it, but in the book Bull’s-Eye: The Assassination and Life of Supergun Inventor Gerald Bull there’s a photo of an electronics package designed by Bull which could have been launched out of the gun. IIRC, one of his ideas was to use the gun to launch satellites.
If we got it up there we could decelerate it to impact wherever we wanted it
1200 pounds at barely sub-orbital speeds is a hell of a surprise.
The first man- made object in space was (possibly) a manhole cover blasted up by a nuclear bomb test in 1957.
IIRC, the US military proposed something like that under the name “Thor.” It was to be orbiting iron bars with precision guidance systems attached to them. The idea being that we could “rain” them down on enemy forces with no danger of losses for our side.
I doubt it would have worked. I’m feeling too lazy to do the math, but maybe someone can calculate the G forces experienced by a projectile fired from the gun described in Tuckerfan’s link? It’s gotta be in the 1000’s of Gs to reach the muzzle velocities described.
Speaking very, very, very technically: You never really ever escape the effects of gravity from earth. The effect just approaches zero asymptotically (sp?). I trust your high school physics teacher once showed the class this decaying curve?
Just making this fact of record.
- Jinx
Not sure about the US military, but a weapons system like this appears in Niven and Pournelle’s Footfall.
Let’s not forget air resistance. Even if the projectile could be accelerated to 11 km/s on the ground, it would lose most of its speed through air resistance before it gets all the way through the atmosphere.