Newsgroups: sci.physics.plasma,sci.energy
From: "Fred McGalliard" <frederick.b.mcgalliard@boeing.com>
Subject: Re: Ground-powered Rocket? Conductive Contrail?
Organization: The Boeing Company
References: <cmr1r7$9k4r$1@saturn.cs.uml.edu>


"sanman" <manofsan@yahoo.com> wrote in message
news:cmr1r7$9k4r$1@saturn.cs.uml.edu...
>
> Another silly idea I'd like to ask about -- could a channel of ionized
> gas be used to feed electric current from a ground station to power a
> rocket ascending to orbit?

Yes, and no. You can open a channel, at some considerable energy
expenditure, but if you pass a current up it, the magnetic field and plasma
pressure tend to kink the path. This looks like the classic linear
discharges, THX I think is one of the fusion experiments using this. The
current produces a field and pinches the plasma. The increasing plasma
pressure tries to stretch it out along the path. Like pushing on a string it
ropes up and twists over itself in fractions of a millisecond. I have never
seen a process that would maintain a steady balanced current, even like the
stellerator where you get to control the magnetic field around the
discharge.

I did like the laser driven air ram. It was designed to focus a received
beam from the rear into a ring style ram jet, heating the air and driving
the ship upward. Neat stunt, and I think demonstrated in the few KW level.
This ship would take several hundred megawatts I think. Big big laser
system, pointed to a small and rapidly retreating object through a badly
distorted air. A related idea would use a space born beam to provide the
energy for a steam rocket operated above most of the atmosphere. Some of
this stuff might work very well for things like material resupply and the
like.








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