A new means of space propulsion... closed loop pulse propulsion... here's the idea

[mikelewis]

23. Ok... you are correct... this is a poor design... let's fix that...

Let's assume some variables and figure this out. I agree, the shooting yourself in the chest model is a poor design and not something I'm really advocating. So let's try some other configurations that have much more predictable outcomes.

First we can assume some weights...
Whatever you like:
We need a railgun setup capable of firing a 10 ounce tethered projectile to say 5 m/s? The length of the tether can be your choice... the longer the better but I don't know, you pick, something that won't break the string or the arm or the cable... whatever you like.

So fire that off... you get the recoil... you get the arc... here's where I get a little fuzzy so I will absolutely rely on your ideas here. I'd put in two railgun setups to off set the gyroscopic effects, which is why I bent the barrels...

Then once the arm pivots to 180 degrees... you just let it stop by hitting the other side. you can catch it in a magnet if you want 100%
power transfer...

We also need to add in the battery and the platform and let's do this way out in space... away from any gravitational issues. This is just a thought exercise. So add in whatever weights make the math easier... and 0 will equal 0 no matter what proportions you use... so we just need the math to back up all that stuff I really didn't understand. Also... we don't need to get down to nitty gritty like Lorentz forces and stuff like that... ball parking it is good enough... 0 = 0... it's not hard. All we have to do is mathematically 0 out that recoil with that setup and you win.