From: LARRY KLAES (ljk4_at_msn.com)
Date: Wed Mar 05 2003 - 11:48:24 PST
The original article can be found on SFGate.com here:
http://www.sfgate.com/cgi-bin/article.cgi?file=/news/archive/2003/03/04/state1534EST0083.DTL
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Tuesday, March 4, 2003 (AP)
Plan to sail space on sun's rays garners interest
(03-04) 18:47 PST TUSTIN, Calif. (AP) --
A plan by a Texas company to send a spacecraft sailing to the stars on the
gentle push of the sun's rays has caught the interest of the National
Oceanic and Atmospheric Administration, which is exploring the technology
for use closer to home.
Team Encounter wants to test a spacecraft with a solar sail by late 2004,
sending it into Earth orbit with messages and photographs tucked aboard by
paying customers.
Once in space, the spacecraft would unfurl an enormous, gossamer sail to
catch the sun's rays, harnessing the gentle -- but constant and cumulative
-- pressure of particles of light to propel it through space.
The sail would be made of Mylar, coated with aluminum and chromium. It
would be 76 times thinner than a human hair and cover a football
field-size area -- but able to fit in a package the size of a breadbox.
"From everything we've seen so far, it's possible. There are no
showstoppers," said Costas Cassapakis, president of L'Garde Inc., the
Tustin company developing the 62,000-square-foot sail and the 164-foot
inflatable booms that would deploy it.
If the orbital mission succeeds, a second spacecraft would be sent out to
the stars with a payload of messages and DNA samples.
While NOAA wants no part of that mission, the technology intrigues it.
"The mission was far out, but the way they were getting at it wasn't,"
said Patricia Mulligan, a NOAA mission planner.
NOAA has paid a small amount to examine Team Encounter's engineering data.
It also wants the Houston-based company to point its craft toward a part
of space the agency wants to exploit for future satellite missions,
Mulligan said.
Solar sails could enable satellites to loiter in space at spots called
Lagrange points, where the gravitational pulls of the Earth and the sun
cancel each other.
A Lagrange-based craft has a stable vantage point above Earth that
traditional orbiting satellites lack. But it also requires constant
adjustment. That can be fuel-intensive for chemically powered spacecraft
but a solar sail doesn't have that problem.
"It relies on the virtually inexhaustible supply of energy from the sun,"
said Charles Chafer, Team Encounter's president and chief executive
officer.
NOAA has preliminary plans for two types of solar sail craft that would
park in Lagrange orbits. One, called Geostorm, would sit part way to the
sun and provide early warning of solar storms before they reach Earth. The
storms -- waves of charged particles from solar flares -- can disrupt
communications networks and power grids.
Another craft, called a polesitter, would linger either above or below the
ecliptic, the plane in which the planets orbit the sun. That would enable
it to stare down on either of the Earth's poles.
Those spacecraft could provide a dedicated communication link for
scientists in the Antarctic, who now must contend with spotty connections
to polar orbiting satellites that pass overhead once every 90 minutes,
Mulligan said.
Team Encounter is considering NOAA's request to fly a solar sail
spacecraft into a polesitting orbit, Chafer said. NOAA has provided
$50,000 to explore if such a mission would be feasible, Mulligan said.
It isn't the only private developer of a solar sail mission, an idea
that's been knocked around for decades. The Planetary Society, a
Pasadena-based space exploration advocacy group, also is working on such a
spacecraft.
The group hopes to launch an eight-petaled solar sail into orbit as early
as August, Executive Director Louis Friedman said.
Project members, who include Ann Druyan, the widow of astronomer Carl
Sagan, hope the craft will move out from the Earth and become the first to
be propelled by sunlight.
"If it spirals outward a few centimeters and we can measure it, then we
can declare victory," Friedman said.
On the Net:
www.teamencounter.com/
www.planetary.org/
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