What is an "electromagnetic explosion"?
Quote from: rakaydos on 02/29/2020 10:44 amWhat is an "electromagnetic explosion"?Nothing. All this concept seems to be is tossing something forward (with a poorly designed rail gun) attached to a tether and then pulling it back. It is entirely missing the "material from the nuclear explosion is expelled backwards" portion of a MEDUSA type nuclear propulsion. This concept would not work.
The trouble with this concept, if I've read it correctly, is that it is incapable of producing sustained, net acceleration without violating the conservation of momentum. At most, a spacecraft would wobble back and forth as the projectile was launched and then reeled back in. You're using your magnetic projectile as a reaction mass (effectively a mass driver based propulsion scheme) ... but then you reel you're reaction mass back in, which would have the effect of exactly cancelling the momentum initially imparted to our putative spacecraft. Virtually every known effective propulsion scheme (exc. light sails and mag-tethers, which aren't exactly in widespread use) involves some sort of reaction mass (gas from chemical rockets or cold gas thrusters, plasma from ion drives) ejected in one direction which pushes the spacecraft in the other direction (Newton's third law). But for this to work, you've got to let the reaction mass go ... you can't reel it back in, or you'll end up right where you started (in the spacecraft's initial inertial reference frame).There are a few ideas floating around in the advanced propulsion concepts arena regarding potential reaction-less drive systems (EM drive, various space drive schemes, various schemes involving the manipulation of gravity, etc.), but these are still very much on the fringe and depend on new physical principals that may or may not actually have anything to do with reality. Perhaps one of these will one day pan out, although the odds on this are likely quite long. What none of these schemes do is try to re-use the same conventional reaction mass over and over - that clearly won't get you anywhere (unless you were already heading that way anyway!).You also mentioned the possibility of generating net power from the winch motor/generator. Unfortunately, this is also a non-starter, as you're violating conservation of energy. If this worked, forget using it for propulsion ... you've made a working perpetual motion machine with a non-zero power output. Your physics Nobel is on the way. Hint: machines of this sort are forbidden by the laws of physics as we currently understand them.Sorry! Nice try though.
Quote from: meberbs on 02/29/2020 09:37 pmQuote from: rakaydos on 02/29/2020 10:44 amWhat is an "electromagnetic explosion"?Nothing. All this concept seems to be is tossing something forward (with a poorly designed rail gun) attached to a tether and then pulling it back. It is entirely missing the "material from the nuclear explosion is expelled backwards" portion of a MEDUSA type nuclear propulsion. This concept would not work.What is important is that the rail gun has hardly any or no recoil.
This excerpt from Solem's paper might make it easier to understand his idea and my idea and why Solem thought he might be able to generate excess electricity. I have attached his paper."When the explosive is detonated, a motorgenerator powered winch will pay out line to the spinnaker at a rate programmed to provide a constant acceleration of the space capsule. The motorgenerator will provide electrical power during this phase of the cycle, which will be conveniently stored. After the space capsule has reached the same speed as the spinnaker, the motorgenerator will draw in the line, again at a rate programmed to provide a constant acceleration of the space capsule. The acceleration during the draw-in phase will be less than during the pay-out phase,which will give a net electrical energy gain. The gain will provide electrical power for ancillary equipment in the space capsule. I have not yet worked out the details of this approach. I will reserve it for a future paper."
It is not a mass driver in the conventional sense because there is little or no recoil when the projectile propelled into space. The moment it is propelled it starts to pull at the cable that is rolled out by the winch at a programmed rate.
I don't think I will end up where I started. As Solem writes the spinnaker (projectile) is not drawn-in until spacecraft and spinnaker (projectile) have the same speed. So both will have traveled a distance before the draw-in phase starts. Basically the spacecraft and spinnaker (projectile) are pulling at each other because the spinnaker (projectile) has kinetic energy and still wants to go forward. Just because the winch on the spacecraft is pulling at the spinnaker (projectile) won't make the spacecraft and spinnaker projectile move backwards.
Quote from: Iggyz on 03/01/2020 01:09 pmQuote from: meberbs on 02/29/2020 09:37 pmQuote from: rakaydos on 02/29/2020 10:44 amWhat is an "electromagnetic explosion"?Nothing. All this concept seems to be is tossing something forward (with a poorly designed rail gun) attached to a tether and then pulling it back. It is entirely missing the "material from the nuclear explosion is expelled backwards" portion of a MEDUSA type nuclear propulsion. This concept would not work.What is important is that the rail gun has hardly any or no recoil.The rail gun will have recoil. That is completely non-negotiable, and how you're electromagnets are arranged will have no effect whatsoever on this. This is a simple question of conservation of momentum. If you can get around this, you're deep into very new, cutting edge physics concepts that may or may not match up with actual reality. But your not going to get there with an electromagnetic rail-gun.
Quote from: cdebuhr on 03/01/2020 02:38 pmQuote from: Iggyz on 03/01/2020 01:09 pmQuote from: meberbs on 02/29/2020 09:37 pmQuote from: rakaydos on 02/29/2020 10:44 amWhat is an "electromagnetic explosion"?Nothing. All this concept seems to be is tossing something forward (with a poorly designed rail gun) attached to a tether and then pulling it back. It is entirely missing the "material from the nuclear explosion is expelled backwards" portion of a MEDUSA type nuclear propulsion. This concept would not work.What is important is that the rail gun has hardly any or no recoil.The rail gun will have recoil. That is completely non-negotiable, and how you're electromagnets are arranged will have no effect whatsoever on this. This is a simple question of conservation of momentum. If you can get around this, you're deep into very new, cutting edge physics concepts that may or may not match up with actual reality. But your not going to get there with an electromagnetic rail-gun.The attached picture might or might not convince you otherwise, but I think it shows how one can negate recoil and still let every action have an equal and opposite reaction.
The attached picture might or might not convince you otherwise, but I think it shows how one can negate recoil and still let every action have an equal and opposite reaction.