starship-design: solar wind plasma sail

[Steve VanDevender <stevev@efn.org>]

Here's an article from the USENET sci.space.news group on a
spacecraft propulsion system that will use a plasma-based
magnetic field generator to allow a spacecraft to be accelerated
by the solar wind.

From: Andrew Yee <ayee@nova.astro.utoronto.ca>
Subject: New spacecraft propulsion method could be out of this solar system 
 (Forwarded)
Newsgroups: sci.space.news
Followup-To: sci.space.policy
Date: Mon, 16 Aug 1999 21:00:28 -0400
Organization: via Internet Direct
Reply-To: ayee@nova.astro.utoronto.ca

University of Washington

FROM: Vince Stricherz, 205-543-2580, vinces@u.washington.edu

FOR IMMEDIATE RELEASE: Aug. 16, 1999

New spacecraft propulsion method could be out of this solar system

It sounds like a "droid" straight out of Star Wars. That's not a coincidence
because a new propulsion system dubbed M2P2 can greatly boost spacecraft
speeds, perhaps to 10 times the velocity of the space shuttle, University of
Washington scientists believe.

NASA's Institute for Advanced Concepts last week awarded a two-year,
$500,000 grant to a UW team headed by geophysicist Robert Winglee to
continue research on Mini-Magnetospheric Plasma Propulsion. If laboratory
work and tests in space succeed, he hopes in 10 years to launch an
M2P2-equipped spacecraft that would become the first from Earth to
leave the Solar System.

That would be quite a feat, considering the craft would have to overtake
Voyager I, launched in 1977 and now about 6.8 billion miles away but still
within the solar system.

Winglee, an associate geophysics professor, has been working on M2P2 the
last nine months with geophysics professor George Parks and John Slough,
a research associate professor of aeronautics and astronautics. They are
developing a prototype and are preparing for tests in the UW's Redmond
Plasma Physics Laboratory.

Their system would use a plasma chamber about the size of a large pickle
jar, perhaps 10 inches by 10 inches, attached to a spacecraft. Solar cells
and solenoid coils would power the creation of a dense magnetized plasma,
or ionized gas, that would inflate an electromagnetic field 10 to 12 miles
in radius around the spacecraft. The field would interact with and be
dragged by the solar wind.

Creating the field would be akin to raising a giant sail and harnessing the
solar wind, which moves at 780,000 to 1.8 million miles an hour -- or
"here to Washington, D.C., in 10 seconds," Winglee said. There is enough
power in the solar wind to move a 300-pound spacecraft at speeds up to
180,000 miles per hour or 4.3 million miles a day. By contrast, the space
shuttle travels at about 18,000 miles per hour or 430,000 miles a day.

At such speeds, an M2P2-equipped spacecraft launched today could
overtake Voyager I within eight years, despite Voyager's 22-year head
start.

The idea for M2P2 grew from the study of plasma jets forming around
young stars, and was formalized in a $75,000 startup grant from the
NASA Institute for Advanced Concepts.

The system has built-in advantages over solar sails, which are very large,
thin sheets of reflective material such as Mylar that can turn sunlight
into a propelling force. Solar sails are typically many times larger than
the spacecraft they propel and must be deployed mechanically. The M2P2
plasma chamber is far lighter and less bulky than sails. Just a few
kilowatts of power would support the magnetic field and only about
100 pounds of additional propellant would be required. Adding the device
to a spacecraft might cost $1 million, but it would provide substantial
cost savings for the overall mission and would provide easier access to
the planets and beyond, Winglee said.

M2P2 could be a major advancement in space travel, but it might be too
tame for two generations that have grown up with science-fiction
adventures such as Star Trek and Star Wars.

"It's amazing how many people say, 'That's not fast enough,'" Winglee said.
"People want to go to warp drive so they can get to the next solar system."

However, Star Trek's warp drive and the hyperdrive propulsion from Star
Wars, both of which can exceed light speed (186,000 miles per second in
a vacuum), are not possible under the current understanding of the laws
of physics.

For now, at least, plasma propulsion could prove to be the best option
to the science fiction propulsion systems. If tests on M2P2 succeed,
Winglee expects the system's first use in space will come on a mission
NASA already will have scheduled.

"If it works, we'll have some real fun then," he said.

###

For more information, contact:
Winglee at (206) 685-8160 or winglee@geophys.washington.edu
Parks at (206) 543-0953 or parks@geophys.washington.edu
Slough at (425) 881-7706 slough@aa.washington.edu

Additional information is available via the Internet at
http://www.geophys.washington.edu/Space/SpaceModel/M2P2/


-- 
Andrew Yee
ayee@nova.astro.utoronto.ca