Mag-beam to Mars?

In this article on MSNBC.com:

http://www.msnbc.msn.com/id/3217961/

"At the start of the trip, the [near-] Earth station would focus its
particle beam on the magnetic sail of a Mars-bound space taxi, pushing it to
speeds of tens of thousands of miles an hour. During the approach to Mars,
the Red Planet station would fire its own beam to decelerate the
spacecraft."

Nowhere is mention made that this particle beam causes any "equal and
opposite" action at the particle-beam source. If this near-Earth station is
blasting a particle beam into space that causes a spaceship to accelerate
(momentum transfer) to "tens of thousands" of mph ... what is the source
doing to maintain position or orbital velocity? Am I missing something?

Jon

On Fri, 15 Oct 2004 14:54:36 -0500, Jon Berndt wrote:

In this article on MSNBC.com:

http://www.msnbc.msn.com/id/3217961/

"At the start of the trip, the [near-] Earth station would focus its
particle beam on the magnetic sail of a Mars-bound space taxi, pushing it to

That JPL/Lockmart JIMO design is sure getting a lot of abuse...last I
looked that graphic had been shanghaied as the carrier craft of
a student tripartite Kuiper Belt probe. Now it's a space station.... JimO
is gaining weight...


Nowhere is mention made that this particle beam causes any "equal and
opposite" action at the particle-beam source. If this near-Earth station is
blasting a particle beam into space that causes a spaceship to accelerate
(momentum transfer) to "tens of thousands" of mph ... what is the source
doing to maintain position or orbital velocity? Am I missing something?

Just handwave in electrodynamic tethers and you can devise a
truly Rube Goldbergian propulsion scheme.

Jon

--
Chuck Stewart
"Anime-style catgirls: Threat? Menace? Or just studying algebra?"

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In article ,
"Jon Berndt" wrote:

In this article on MSNBC.com:

http://www.msnbc.msn.com/id/3217961/

"At the start of the trip, the [near-] Earth station would focus
its particle beam on the magnetic sail of a Mars-bound space taxi,
pushing it to speeds of tens of thousands of miles an hour. During
the approach to Mars, the Red Planet station would fire its own
beam to decelerate the spacecraft."

Nowhere is mention made that this particle beam causes any "equal
and opposite" action at the particle-beam source. If this
near-Earth station is blasting a particle beam into space that
causes a spaceship to accelerate (momentum transfer) to "tens of
thousands" of mph ... what is the source doing to maintain position
or orbital velocity? Am I missing something?

Jon

One of the summaries I saw made mention of an interaction between the
particle beams, a type of solar sail and the solar wind. Perhaps that
is the key.

Alternately, the developers - as theoreticians rather than engineers,
forgot that inconvenient little F=ma thing . . . :-)
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--
Herb Schaltegger, B.S., J.D.
"Never underestimate the power of human stupidity."
~ Robert A. Heinlein
http://www.angryherb.net

Jon Berndt wrote:
In this article on MSNBC.com:

http://www.msnbc.msn.com/id/3217961/

"At the start of the trip, the [near-] Earth station would focus its
particle beam on the magnetic sail of a Mars-bound space taxi, pushing it to
speeds of tens of thousands of miles an hour. During the approach to Mars,
the Red Planet station would fire its own beam to decelerate the
spacecraft."

Nowhere is mention made that this particle beam causes any "equal and
opposite" action at the particle-beam source. If this near-Earth station is
blasting a particle beam into space that causes a spaceship to accelerate
(momentum transfer) to "tens of thousands" of mph ... what is the source
doing to maintain position or orbital velocity? Am I missing something?

Jon



You hold your foot on the brake while the beam is on. Natch.


TBerk

Jon Berndt wrote:
In this article on MSNBC.com:

http://www.msnbc.msn.com/id/3217961/

"At the start of the trip, the [near-] Earth station would focus its
particle beam on the magnetic sail of a Mars-bound space taxi, pushing it to
speeds of tens of thousands of miles an hour. During the approach to Mars,
the Red Planet station would fire its own beam to decelerate the
spacecraft."

Nowhere is mention made that this particle beam causes any "equal and
opposite" action at the particle-beam source. If this near-Earth station is
blasting a particle beam into space that causes a spaceship to accelerate
(momentum transfer) to "tens of thousands" of mph ... what is the source
doing to maintain position or orbital velocity? Am I missing something?

If the station is in orbit, then half the time the push is increasing
orbital velocity and half the time it is decreasing orbital velocity.
The net effect is to push the planet it is orbiting.

Alain Fournier

Jon Berndt wrote:

Nowhere is mention made that this particle beam causes any "equal and
opposite" action at the particle-beam source. If this near-Earth station is
blasting a particle beam into space that causes a spaceship to accelerate
(momentum transfer) to "tens of thousands" of mph ... what is the source
doing to maintain position or orbital velocity? Am I missing something?

If the transmitter is in orbit around Earth, the net effect would be
to displace the orbit slightly, so that the momentum is transfered
to the planet.

Paul

"Paul F. Dietz" wrote:

Jon Berndt wrote:

Nowhere is mention made that this particle beam causes any "equal and
opposite" action at the particle-beam source. If this near-Earth station
is
blasting a particle beam into space that causes a spaceship to
accelerate
(momentum transfer) to "tens of thousands" of mph ... what is the source
doing to maintain position or orbital velocity? Am I missing something?

If the transmitter is in orbit around Earth, the net effect would be
to displace the orbit slightly, so that the momentum is transfered
to the planet.

Paul


I wonder if the idea is to have complete visibility of the interplanetary
probe at all times? This would dictate a polar orbit. Maybe that would work
better. Also, for redundancy, perhaps there would be several of the
particle-beam generators in orbit about source and destination planets ...

Jon

- Magnetized Beamed Plasma Propulsion (PI: Dr. Robert M.
Winglee of the University of Washington, Seattle)


It's cool to see that Robert Winglee has been awarded a NASA Institute
for Advanced Concepts (NIAC) project to develop a plasma beam to push
a M2P2 magnetic plasma sail for space propulsion. It sounds like an
excellent project which has the potential to revolutionize high
delta-V space propulsion.

I do want to mention that, in part, the concept develops out of my
previous study of a particle-beam pushed magnetic sail, presented at
the 2001 STAIF Conference:

G. A. Landis, "Interstellar Flight by Particle Beam," presented at the
Space Technology and Applications Intenational Forum Albuquerque NM,
Feb. 11-15, 2001. American Institute of Physics Conference
Proceedings Volume 552, pp. 393-396.

Coincidentally, the refereed-journal version of this article has just
come out:
G. Landis, "Interstellar Flight by Particle Beam," Acta Astronautica.
Vol 55, No. 11, 931-934 (Dec. 2004). [Copies available by request.]
It is published online via ScienceDirect: (
http://authors.elsevier.com/sd/artic...9457650400133X )

--
Geoffrey A. Landis
http://www.sff.net/people/geoffrey.landis

everybody has knocked this theory of travel alot. But does anyone actual
think it will work...

"Chuck Stewart" wrote in message
news
On Fri, 15 Oct 2004 14:54:36 -0500, Jon Berndt wrote:

In this article on MSNBC.com:

http://www.msnbc.msn.com/id/3217961/

"At the start of the trip, the [near-] Earth station would focus its
particle beam on the magnetic sail of a Mars-bound space taxi, pushing
it to

That JPL/Lockmart JIMO design is sure getting a lot of abuse...last I
looked that graphic had been shanghaied as the carrier craft of
a student tripartite Kuiper Belt probe. Now it's a space station.... JimO
is gaining weight...


Nowhere is mention made that this particle beam causes any "equal and
opposite" action at the particle-beam source. If this near-Earth station
is
blasting a particle beam into space that causes a spaceship to
accelerate
(momentum transfer) to "tens of thousands" of mph ... what is the source
doing to maintain position or orbital velocity? Am I missing something?

Just handwave in electrodynamic tethers and you can devise a
truly Rube Goldbergian propulsion scheme.

Jon

--
Chuck Stewart
"Anime-style catgirls: Threat? Menace? Or just studying algebra?"

"Chuck Stewart" wrote in message
news
On Fri, 15 Oct 2004 14:54:36 -0500, Jon Berndt wrote:

Nowhere is mention made that this particle beam causes any "equal and
opposite" action at the particle-beam source. If this near-Earth station
is
blasting a particle beam into space that causes a spaceship to
accelerate
(momentum transfer) to "tens of thousands" of mph ... what is the source
doing to maintain position or orbital velocity? Am I missing something?

Just handwave in electrodynamic tethers and you can devise a
truly Rube Goldbergian propulsion scheme.

Bob Forward has the same problem with his laser-propelled sail. His laser
array was orbiting Mercury in a plane perpendicular to the path of the
receding sail. When the lasers fired, the orbit was displaced slightly from
the plane cutting through the center of gravity of Mercury, but the array
continued orbiting and didn't leave.

See no reason one couldn't do the same from Earth.

--


Regards,
Mike Combs
----------------------------------------------------------------------
Member of the National Non-sequitur Society. We may not make
much sense, but we do like pizza.