Re: hyperspace (was: cloaking device rules)

FieldScott@aol.com writes:
@:) Alun writes:
@:) 
@:) >  There's no reason why you can't pump water through the core,
@:) >  let the core heat it into high preasure steam, and allow the
@:) >  steam to escape through the back of your ship - and there you
@:) >  have it: THRUST
@:) 
@:) Very true, but then you still have an expendable fuel: water! When
@:) you run low on water, you have to head back to dock. And since
@:) water can't be compressed, a large chunk of your mass is going to
@:) be taken up with water storage. I'm trying to dream up a system
@:) that doesn't require frequent re-fueling.

  Well NASA has been thinking about the same stuff and they came up
with the ion engine (maybe also called something like the electric
propulsion system?) which is about as close to what you're asking
about as we currently have.  This system uses an electric field
(there's a magnetic field variant that may actually be more useful) to
propel ionized particles out the back of the spacecraft, generating
thrust.  The nice thing about it is that, since the particles are
expelled at extremely high velocities (compared with a traditional
rocket engine) the engine is quite fuel efficient.  The first probe
scheduled to use it (Argh my browser isn't getting through to the NASA
site and I forgot which probe it is!) is supposed to carry eighty
pounds (kilos?) of fuel which was supposed to be enough for several
years of operation.

  The downside to the ion engine, despite Mr. Lucas' wishful thinking,
is that they generate very little thrust.  That means that ships
propelled by them will accelerate very, very, slowly.  The theory is
that you turn the engine on at the start of your trip and you turn it
off when you get there and it's running the whole time.  This in
contrast to a chemical rocket engine, which is turned on once at the
beginning of the trip, for maybe a minute or two, and then once again
at the end, again for around a minute.	Each time they're on, they
provide a huge kick to the spacecraft.

  So anyway, check out www.nasa.gov and look around till you find
the ion engine site.  They have some great pictures of the thing
running - no flame or anything, just this eerie blue glow.  Not
entirely unlike the engines on Star Wars vehicles, but a lot dimmer.

-joachim