3 ms·

He mentioned it toward the end, but did not describe the solution. I'm thinking the counterweight on the other end would need to move a very precise distance i

by finnh 5y ago

He mentioned it toward the end, but did not describe the solution. I'm thinking the counterweight on the other end would need to move a very precise distance in effectively zero time. EDIT: hmm, or a supplemental weight on the payload side, moving outward the right distance as the payload releases. It seems like you'd generally want the non-payload rotating bits to vastly outmass the payload, so its release perturbs the whole system to the least amount possible. And then you use regenerative braking to reclaim the energy .

avereveard 5y ago
I wonder why they don't just have an inert concrete mass on the other side and an exit port that opens into a sand bunker, sure it's a lot of energy but they don't have to contain it, only limit back splash from the mass hitting the sand. Doesn't even need to be enough sand to stop the mass completely, just enough to catch fragments, the mass can continue into the earth with no consequences
- dvdkhlng 5y ago
  Yes, that's an intriguing idea. What I came up with was this: the launch arm has a second mass inside it, that will move (via centrifugal force) away from the center, in the same moment the payload is released. Of course, just having two payloads launch in opposite direction as you propose maybe has much less implementation problems (though I wonder how you stop that second dummy payload in a way that does not cause an earthquake or explosion :)
- bufferoverflow 5y ago
  Sand will melt with all the energy absorbed. Water is much better.
jessriedel 5y ago
You'd need to reclaim a lot of energy very quickly because after the projectile's exit the atmospheric pressure is going to slow you down right quick
- mgsouth 5y ago
  You could slam a blast door closed behind the exiting projectile. It should be possible to place it in the exit tunnel so that it is fully closed before the inrushing atmosphere gets to it.
  - jessriedel 5y ago
    Plausible. Do you know how fast such doors can close?

by finnh 5y ago

avereveard 5y ago

I wonder why they don't just have an inert concrete mass on the other side and an exit port that opens into a sand bunker, sure it's a lot of energy but they don't have to contain it, only limit back splash from the mass hitting the sand. Doesn't even need to be enough sand to stop the mass completely, just enough to catch fragments, the mass can continue into the earth with no consequences

dvdkhlng 5y ago
Yes, that's an intriguing idea. What I came up with was this: the launch arm has a second mass inside it, that will move (via centrifugal force) away from the center, in the same moment the payload is released. Of course, just having two payloads launch in opposite direction as you propose maybe has much less implementation problems (though I wonder how you stop that second dummy payload in a way that does not cause an earthquake or explosion :)
bufferoverflow 5y ago
Sand will melt with all the energy absorbed. Water is much better.

jessriedel 5y ago

You'd need to reclaim a lot of energy very quickly because after the projectile's exit the atmospheric pressure is going to slow you down right quick

mgsouth 5y ago
You could slam a blast door closed behind the exiting projectile. It should be possible to place it in the exit tunnel so that it is fully closed before the inrushing atmosphere gets to it.
- jessriedel 5y ago
  Plausible. Do you know how fast such doors can close?