zolikk t1_j6nso2v wrote on January 31, 2023 at 5:21 PM

Reply to comment by [deleted] in If the concepts of Project Orion were proven, why don't we use them for space guns? by [deleted]

You have to make a rendezvous with the ISS which means you have to have propulsion on your "vehicle", it can't just be a "cannonball" fired from the ground once. And the engine and other delicate components necessary wouldn't survive being fired out of such a cannon.

To put it simply, you cannot shoot an unpowered object into orbit. Its path intersects the earth again, or it attains escape velocity and leaves earth permanently, but neither path makes an orbit.

[deleted] OP t1_j6nt4al wrote on January 31, 2023 at 5:24 PM

[deleted]

zolikk t1_j6ntj8h wrote on January 31, 2023 at 5:26 PM

Hmm, I guess it's possible? But then it requires quite a lot of constant fuel for your orbital retrieval vehicle. I suppose you could also "shoot" fuel up with the cannon constantly.

I'm not convinced it could be worth it. From the construction and maintenance of the cannon to the reliability of the method, even if possible, where if you don't catch a payload perfectly it just falls back to earth... rocket launches are probably more worthwhile for all this.

Since you need fuel to get into orbit you're still beholden to the rocket equation where you're using fuel that you catch to put the payload you also catch into orbit... I don't think you're necessarily that far from just using rockets, except the reliability problem.