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Comment by JamesBaxter | Hacker News Reader

Was the purpose of the cannon to take down other satellites or just for research purposes? Presumably whilst this appears to be a weapon with a considerable range, satellites don't operate that close to each other?

The mathematics to calculate hitting another satellite traveling in a different orbit and at a different speed sounds like an interesting challenge.

If you were trying to disable a satellite what would be the best target? Solar cells?

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> The mathematics to calculate hitting another satellite traveling in a different orbit and at a different speed sounds like an interesting challenge.

It's the exact same mathematics you already need to be able to dock spacecraft, change orbits, or get into orbit in the first place. Any organization capable of putting things in orbit would have no trouble, it's just a case of plugging some different numbers in.

> If you were trying to disable a satellite what would be the best target? Solar cells?

Relative velocities are going to be enormous without even trying, so it doesn't matter where you hit it - the energy will have to go somewhere.

> Relative velocities are going to be enormous without even trying, so it doesn't matter where you hit it - the energy will have to go somewhere.

With so much energy, it really doesn't matter? I imagine it would look like shooting a bullet through cardboard - the latter gains a hole, but otherwise doesn't even notice. Energy generally stays in the bullet that continues its flight.

What happens when you shoot a piece of cardboard with a bullet in a vacuum though?

(I'm much less confident than I was FWIW)

You know, it seems to me that something that fired chain shot^ would have been better than straight bullets.

^https://en.wikipedia.org/wiki/Chain-shot

I imagine the trouble with that is the weight and associated costs of getting that weight into space.

The quoted range was two miles though I have to think that was within the atmosphere. Even in LEO something fired @ 1500mph relative to the source should continue to travel at that speed unless it interacts with something no?

It'd slow down eventually, LEO still has a really thin atmosphere that would still affect a bullet, it'd be way longer than 2 miles though. Effective range makes more sense for a spacegun and would be more of your ability to accurately point and fire than the distance the round could travel. If you can only accurately hit objects within 2 miles the fact that the rounds would orbit for a while doesn't really matter.

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