3 ms·

There are about a dozen serious problems with this plan. What happens to the rest of your spin system when your payload releases? What about air resistance? If

There are about a dozen serious problems with this plan. What happens to the rest of your spin system when your payload releases? What about air resistance? If you’re spinning up in a vacuum what happens when your payload hits atmosphere at orbital velocity? What are your neighbors going to think about living near complicated, delicate, high velocity things like this? I also take issue with the notion that “scientists” are working on this. Engineers? Yes. Dreamers with a nifty idea? Yes. Will it ever work? Maybe if what seem like insurmountable problems get solved. I’m not holding my breath though, and I don’t want to be within 10 miles or anywhere down range of the attempt.

feoren 5y ago
> What happens to the rest of your spin system when your payload releases? I mean, it's anchored to the ground, right? I'm sure it takes a shock but it shouldn't be out of the realm of stresses we already deal with regularly. > What about air resistance? ... what happens when your payload hits atmosphere at orbital velocity? This and the high Gs that must be involved are the biggest worry for me. Max Q is at full atmosphere right outside of the barrel of your gun? Protecting the payload and preventing the rocket from immediately disintegrating seems like the hardest part here. But it doesn't seem unsolvable if you can just glop on more and more shielding now that weight isn't as much of a concern. > What are your neighbors going to think I mean, there's always the deserts of Nevada.
- mcguire 5y ago
  "* > What happens to the rest of your spin system when your payload releases?* "I mean, it's anchored to the ground, right? I'm sure it takes a shock but it shouldn't be out of the realm of stresses we already deal with regularly." Consider having one arm on the rotational axis. While it is spinning up, the axle is under significant stress, with the mass of the arm plus the mass of the vehicle under significant centrifugal force (Scott Manley says 10,000G at peak loading), which is a hard problem in itself. When you release the vehicle, the vehicle mass portion of that force goes to zero effectively instantly. Not a mechanical engineer, but I would expect a certain amount of vibration. Or possibly rapid disassembly. It's better if you have two arms with the vehicle on one and an equivalent mass on the other---when you launch the vehicle, you drop the other mass in the opposite direction. (Which is quite a synchronization problem.) (But where does that mass go?)
  - feoren 5y ago
    > (But where does that mass go?) Spitballing here ... the mass is magnetic, and you shoot it down into a giant borehole that rapidly recaptures the momentum using magnetic regenerative breaking. Of course you need to use all the energy you recaptured (and more) to bring the mass back up to the surface for your next launch ... Ok, maybe we are starting to get into sci-fi ...
    - emaginniss 5y ago
      It was sci-fi quite a while ago

feoren 5y ago

> What happens to the rest of your spin system when your payload releases? I mean, it's anchored to the ground, right? I'm sure it takes a shock but it shouldn't be out of the realm of stresses we already deal with regularly. > What about air resistance? ... what happens when your payload hits atmosphere at orbital velocity? This and the high Gs that must be involved are the biggest worry for me. Max Q is at full atmosphere right outside of the barrel of your gun? Protecting the payload and preventing the rocket from immediately disintegrating seems like the hardest part here. But it doesn't seem unsolvable if you can just glop on more and more shielding now that weight isn't as much of a concern. > What are your neighbors going to think I mean, there's always the deserts of Nevada.

mcguire 5y ago
"* > What happens to the rest of your spin system when your payload releases?* "I mean, it's anchored to the ground, right? I'm sure it takes a shock but it shouldn't be out of the realm of stresses we already deal with regularly." Consider having one arm on the rotational axis. While it is spinning up, the axle is under significant stress, with the mass of the arm plus the mass of the vehicle under significant centrifugal force (Scott Manley says 10,000G at peak loading), which is a hard problem in itself. When you release the vehicle, the vehicle mass portion of that force goes to zero effectively instantly. Not a mechanical engineer, but I would expect a certain amount of vibration. Or possibly rapid disassembly. It's better if you have two arms with the vehicle on one and an equivalent mass on the other---when you launch the vehicle, you drop the other mass in the opposite direction. (Which is quite a synchronization problem.) (But where does that mass go?)
- feoren 5y ago
  > (But where does that mass go?) Spitballing here ... the mass is magnetic, and you shoot it down into a giant borehole that rapidly recaptures the momentum using magnetic regenerative breaking. Of course you need to use all the energy you recaptured (and more) to bring the mass back up to the surface for your next launch ... Ok, maybe we are starting to get into sci-fi ...
  - emaginniss 5y ago
    It was sci-fi quite a while ago