-
- Scientists with the US space agency Nasa
have taken an old idea as they try to develop new ways of travelling into
space.
-
- They hope magnetic levitation - or maglev
- could help launch spacecraft into orbit using magnets to float a space
vehicle along a track.
-
- The concept is already widely used in
amusement parks and Nasa has enlisted the help of a fairground ride manufacturer,
along with a university in the UK.
-
- Magnetic levitation uses an ordinary
electrical motor which normally converts electricity into rotary energy.
-
- But in this case the motor - formed from
magnets - is unrolled so that it is flat.
-
- If a metal object is then held above
the spaced-out magnets, it will float in the air, levitated by the magnetic
fields.
-
-
- Cut-price space travel
-
-
- Nasa experts believe that magnetic levitation
could slash the cost of space travel.
-
- The agency's Advanced Space Transportation
Program at the Marshall Space Fight Center in Alabama is behind the project.
-
- "Magnetic levitation is a promising
technology for future space transportation as we build the highway to space,"
said Garry Lyles, manager of the Advanced Space Transportation Program.
-
- "The most expensive part of any
mission to low-Earth orbit is the first few seconds - getting off the ground.
Maglev is a low-cost alternative for space transportation because it leaves
the first-stage propulsion system on the ground."
-
- High-strength magnets are already used
to lift and propel high-speed trains and roller coasters a couple of inches
above a guideway.
-
- A maglev launch-assist system would be
used to drive a space vehicle down a track in a similar way, but at speeds
of 600mph.
-
- A rocket engine would then take over
to enable spacecraft to reach orbit.
-
- "A maglev system is virtually maintenance-free
because it has no moving parts and there's no contact," said Mr Lyles.
-
- "It could help launch a spacecraft
from a typical airport runway to low-Earth orbit every 90 minutes."
-
-
- Large scale
-
-
- Experiments to test the theory have been
carried out the University of Sussex in England.
-
- In a laboratory there, a two-feet-long
sled is propelled at 120mph along a 20-feet electromagnetic track.
-
- Motors for the experiment were developed
by PRT and funded by Arrow Dynamics Inc.of Utah, an amusement ride manufacturer.
-
- As part of a larger scale experiment
in 1999, two longer tracks measuring 50 and 400 feet are planned in Huntsville.
-
- Design plans will soon be completed for
a 5,000-foot track capable of launching a 40,000lb payload at a test site.
-
- Some scientists believe that as early
as 2007, a maglev launch assist system could be used to launch very small
communications satellites for thousands of dollars per pound, far cheaper
than current costs.
-
____________
-
- Date: Thu, 08 Oct 1998 13:08:40 -0700
- From: "Richard Johnson" <RichardJ@hlyw.com
- To: eotl@west.net
- Subject: Re: Nasa and Maglev
-
- Good day.
-
- Here are some follow-up thoughts your posting on NASA
examining maglev as a first stage booster engendered.
-
-
- " ... magnetic levitation could slash the cost
of space travel.
-
- The problems are political, not technical.
-
- The technology is fairly mature, except for designs that
deal with supersonic shock waves. Making maglev common would provide a
more cost-effective way to start private space ventures--and open a black
market for rail guns. Our satellite launcher is Quadaffi's intercontinental
cannon.
-
-
- " ... a two-feet-long sled is propelled at 120mph
along a 20-feet " electromagnetic track.
-
- So much for using these to move people to orbit. 120mph
in 20 feet is just over 24g acceleration. Imagine going 60 to 0 in ten
feet without an air bag. :-) Linear motors could be built to move people
and animals, but the fixed costs would be high. To get to 120mph at a
more modest 3g would require about 320 feet of track. Rails to boost people
would be miles long, and presumably up the side of Andean mountains.
-
- Might be good for the steel industry.
-
- Thanks for a great show and a great website
-
- Richard Johnson
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