Person012345, I'm sorry, but you are not very accurate in description of my statements. You mixed me up with
Hazard and, from the other side, it was
my statement, that plasma is not technically a gas. And there are some other fine points, where I suspect, that you mixed up smth too. Therefore, I suspect that you are in some misunderstanding about my point at all.
Again.
When you are tossing nuclear tablets for NP drive - it is the same, as you are tossing fuel (chemical, or nuclear, or matter-antimatter, it doesn't matter) to the combustion chamber.
But rocket engines are
not propel their ships just tossing out propulsion mass from the combustion chamber. They are propel their ships, when they tossed smth out from the
nozzle:
As you can see at the picture, main pressure asymmetry - it is an asymmetry at the back surface of nozzle, not at the inner surface of the ship. There
is a reason to use nozzle, not a simple hole in the combustion chamber. Propulsion pressure tosses your ship, when it's propulsion mass is already
out of your ship.
And what is a difference with NP engine?
At the first look, the difference is, that NP engine can work with outer combustion. It can have no combustion chamber at all, and it's nozzle have another (more open) form.
Indeed, NP engine also can
have usual inner combustion chamber and usual form of nozzle, if you have a stuff like Duranium, that will endure such inner impact.
The difference between Nuclear Pulse engine and other propulsion engines (nuclear or chemical) is
not in outer combustion.
The difference is in
pulse combustion.
The same pulse, as in those old German V-1 pulse rocket engines, neglecting that V-1 used chemical fuel, not nuclear, because Germany has no nuclear drive tech.
As for classical Orion NP drive - it have outer combustion, yes. But there is still no principal difference. Outer combustion or inner combustion - both ways you have to combust some matter to create pressure at the back of your ship, that will be asymmetrical when bump this ship, tossing it forward. It is absolutely the same, as to say, that you are tossing smth back from the back of this ship.
And there is a principle of momentum conservation law, as it is. Tossing smth back is tossing smth forward, and no other way (and gravitational maneuvers and light sails are not exceptions - all of them are tossing smth back too: gravitational maneuver is tossing major mass, using it's own gravitation; light sail is the same as foton drive, though it looks very couterintuitive, because light sail can use a star or outer laser as a part of itself).
And if you want to have an
effective drive (as
Hazard wrote, when our conversation start) - you must toss smth with full close control of the process. It is - to toss smth from the back of your ship, as in the picture above. Any other known way will be ineffective from our Aurorian point of view, and from any hard-fiction point of view at all.