FYI,

"SPACE.com Exclusive: Breakthrough In Solar Sail Technology"
SPACE.com
http://www.space.com/businesstechnology/technology/carbonsail_000302.h
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: A remarkable new carbon-fiber material is causing a revolution in
: the way scientists are thinking about laser and solar sails,
: according to engineers at NASA's Jet Propulsion Laboratory (JPL).

: The fiber is a departure from solar sails of the past: it is about
: 200 times thicker than the thinnest solar sail materials, but so
: porous that it weighs the same.

: In space, solar sails would reflect photons of sunlight, thus
: harnessing their momentum. The sails, which could also be propelled
: by lasers, must be super-lightweight in order to benefit from the
: massless particles bouncing off their surfaces.

: Solar sails are now the propulsion method of choice for proposed
: NASA programs that strive to travel past the boundaries of the
: solar system, and to keep a gargantuan telescope hovering in space.

: The new carbon fiber mesh, which is developed by Energy Science
: Laboratories, Inc. in San Diego, California, could be the first
: step. The mesh is composed of a network of carbon fibers crisscross
: linked into a matrix that is mostly empty space. One hundred of
: these carbon fibers bunched together would make up a strand the
: size of a human hair.

: The fabric is receiving tremendous notice because of its promise to
: self-deploy. Instead of having complicated and cumbersome
: deployment mechanisms to unpack and stretch out films in space,
: this carbon scrub-pad material could be packed so that it pops out
: flat once it is released.

: The carbon fiber is also a great leap because it can tolerate
: temperatures as high as 4,500 degrees Fahrenheit (2,500 degrees
: Celsius). This gives it a great versatility and durability that
: other materials lack, said Charles Garner, a JPL senior engineer
: who works with solar sails.

: "The dream would be then you can make these ultra-, ultra-
: lightweight solar sails out of carbon fiber that can be either
: taken very, very close to the sun to get a big kick, or can be hit
: with large amounts of laser power or microwave power," Garner said.

: Recent experiments at JPL have demonstrated that lasers can indeed
: push this carbon material, which glows hot orange and white from
: the power of the laser beam, but keeps its integrity as a sail.

: Henry Harris, a JPL engineer who is managing research into laser
: and microwave propulsion, said the materials are a huge advance.

: "We got the temperature of the sail up to 2,600 degrees Centigrade
: (4,712 degrees Fahrenheit), which is really good news," Harris
: explained. "What it means is that it's like any kind of engine: we
: can run the engine at much higher power levels than we had
: previously anticipated because we're using advanced materials. And
: so that has tremendous implications for the future of interstellar
: spaceflight."

: "When you see the stiffness of these things you don't have to limit
: yourself to thinking about sails. They can be antennas, they can be
: propulsion systems like sails, or they can be support structures
: for other things that a spacecraft needs," such as solar cells, or
: optical sensors, or even flexible electronics circuits, he said.

Mark Reiff