From: manofsan@yahoo.com (sanman)
Newsgroups: sci.physics.plasma,sci.energy
Subject: Ground-powered Rocket? Conductive Contrail?
Date: 9 Nov 2004 09:55:48 -0800
Organization: http://groups.google.com


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?

I've read about femtosecond-pulse lasers being used to create
persistent conductive channels through the air. They have been used to
make instant "virtual lightning rods" to divert lightning bolts away
from skyscrapers or airports, when a storm appears.

If the tremendous electrical power of a lightning bolt can be conveyed
down such
an ionized channel from the sky to the ground, then why can't
electricity be conveyed up it to reach a rocket travelling upwards?

As we just covered before, the atmosphere only extends up a couple of
dozen miles, but could one perhaps use a rocket's exhaust contrail to
create a conductive/ionized channel along it? You could then feed
current from your ground-based power station up that conductive
channel. (LOL, would sort of give new meaning to the phrase
"Fly-by-wire"!)

You'd need to keep your conductive exhaust contrail from
dispersing/dissipating, so you'd be hostage to
wind/weather/localized-turbulence on the way up. Perhaps you'd use
Doppler Radar to help you pick the right time and place for good
launch conditions. But if it only takes about 8 minutes for the
Shuttle to reach orbit, then using that as a guide, perhaps that's a
reasonable window for the exhaust contrail to remain cohesive. And if
it's not a manned payload, perhaps you'd have higher acceleration and
even quicker travel time to orbit.

(Hmm, I guess they don't have many hydroelectric dams in the Mojave
Desert, so you'd have to build a nuclear reactor out there. Or perhaps
a mobile rolling nuclear reactor? Or a ship-borne one, if you're
launching out at sea?)

Would you absolutely need the laser to make the exhaust contrail
conductive? It would help, but then you're going to need the exhaust
contrail to be in a straight line. Perhaps one could select exhaust
gas(es) that would facilitate the conductivity and also favor staying
cohesive? If your conductive contrail could work all by itself without
any ionizing laser to aim, the nice thing about it is that your
current would just "follow the trail" and always make it to the
target.

We know that exhaust contrails are often so visible in the sky because
the exhaust gases condense into little ice crystals in the cold of the
upper atmosphere. I don't know if this would be a good thing or a bad
thing. The frozen crystals might fall more quickly, but they'd only
appear in the atmospheric portion of the contrail, which is vertical
anyway, so hopefully falling wouldn't distort the contrail shape too
much. Maybe the passage of enough current would keep the contrail hot,
and prevent condensation/freezing.

What about a particle beam of accelerated ions? Could that be used as
a channel for electric current to travel up, instead of the exhaust
contrail? I know people have suggested microwave beaming, but they
would be a lot more dangerous to a crew/cargo than electric current,
IMHO.

So what do you think of these approaches? Has anybody ever suggested
any of this
before? What are the shortcomings and difficulties?





WS3-FO: This message has been scanned by the UMass Lowell Anti-Virus Scanning
Service