Engines in Star Wars, manoeuvering and braking

[Mr. Oragahn]

In that recent SBC thread about giganto ships crashing into planets, I finally came to quickly adress a point that's been buzzing around in my mind for many years, but I really didn't bother that much.

The question is just how an ISD, for example, is supposed to slow down, since it lacks frontal thrusters.
The idea that most people have been agreeing on is that they recreate a whole new path for the ejecta, by the help of forcefields.

Of course, one would say it would be simpler to just put holes in the front of your ship, but nevermind.
So since the engines on an ISD, despite being said to be ion engines I think, also use coned nozzles, we know that the good old rocket engine principle still as something to do here.
I came with a quick graphic about how the force fields should be shaped to generate a retro thrust.

It's rather rough, and doesn't specify that the rear cone should be created quite at a distance from the ship, to avoid redirecting the ejecta onto the ISD's stern, which would in return push it forward again to some moderate extent.



The green things are the forcefields. The tighter one has is a cone with its tip severed. This one should be shorter, I suppose. The second force field is a "bowl".
Does that look relatively good?

It doesn't include electromagnetic fields to accelerate, slow down or redirect ions btw.

Now, what do you think about the Invisible Hand's braking system, seen in ROTS?
Don't you think it would have been a tad better if the panels, instead of being purely planar, were shaped like lenses?

In the case of these planar panels, how much force do you think is actually lost due to scalar work?

Now, as a second part of this thread, do you think X-wings and hyperspace rings have the capacity to direct the ejecta forward?
What's the EU take on this? Do they say the openings are only radiators and air intakes (in case of atmospheric flight)?

Essential Guide: X-wing
ICS: hyperspace module



Star Wars Sourcebook (a cross section not too different than the one from the ICS).
It seems the design doesn't allow the engine to redirect the ejecta forward.

The structural design of Y wings' engines is interesting. It seems to allow for a great mix of solid and force field deflectors to easily reorient the ejecta.

[GStone]

Are you thinking the repulsorlift drive adapter is the force field generator to redirect the ion emissions?

This would mean the emitter nozzles would have to be about twice as strong, so you don't burn off the outer side when you want to slow down.

[Mr. Oragahn]

Are you thinking the repulsorlift drive adapter is the force field generator to redirect the ion emissions?

I don't know. Maybe. Repulsors work only against gravity. When you have mass, you have gravity, even if it's negligible. Maybe some small repulsor fields can be generated at the end of the nozzle to deflect mass.

This would mean the emitter nozzles would have to be about twice as strong, so you don't burn off the outer side when you want to slow down.

Yes, but I think the good system would actually make sure the ejecta isn't fired towards any part of the ship.

[SailorSaturn13]

I'd say X-Wing, like modern rockets, simply turns 180° and accelerates into opposite direction. Now the question is HOW it turns. This may be done with small secondary ejecta points, which could be minuscule compared to main ones and still turn an X-Wing around quickly, OR it redirect ejecta PARTLY to a side

[Mr. Oragahn]

I'd go for the vectored thrust by the use of force fields, or eventually, if on the inside of the nozzles, there are panels which can be moved.

[Kazeite]

Keep in mind that repulsors don't seem to generate any kind of thrust - witness Qui-gon and Jar-Jar getting under TF transport and not getting squashed flat :)