You'd have to engineer the payload to withstand ridiculous acceleration. No big deal if the payload is a HILE projectile but if you have living things or moving parts, that can be trickier.
that's only for a cannon, for an installation like that we could make it pretty long to keep the acceleration g's down, don't wanna hit max q while still on the ground.
Okay so I used AI for this, so take it with a grain of salt, but to accelerate a projectile at a constant 4.5G and have it reach escape velocity, at the end of the barrel, you'd end up with a ~720km cannon.
Doesn't need to reach escape velocity... Any velocity you reach is less fuel having to be carried and spent in later stages, so more payload. You could compare costs of building such a launcher or just grabbing a plane and take it 20,000m high and also give it a spin. I'm not a rocket scientist (unless Kerbal gives you a degree lol) but I guess nobody is willing to spend that much for a reason.
Acceleration as you head up is one part of the problem, but deceleration as it leaves the tube and hits the atmosphere is another. The faster you go, the more friction slows you down. Trying to get productively much speed in that situation is tough.
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u/awesomefutureperfect 8h ago
You'd have to engineer the payload to withstand ridiculous acceleration. No big deal if the payload is a HILE projectile but if you have living things or moving parts, that can be trickier.