[meteorite-list] Solar sail launches today

[Darren Garrison]

http://www.cnn.com/2005/TECH/space/06/21/russia.cosmos.reut/index.html

LOS ANGELES, California (Reuters) -- The world's first solar sail spacecraft takes flight on
Tuesday, launched by space enthusiasts who cobbled the privately funded mission together on $4
million and an untested theory that light can power limitless space exploration.

Cosmos 1, a disc-shaped craft whose two segmented sails suggest flower petals, is set to blast off
from a submerged Russian submarine in the Barents Sea at 12:46 p.m. PDT (1746 GMT) on Tuesday.

Mission controllers hope to fill each sail's four 49-foot (15-meter) segments with streams of
photons, or light particles, emanating from the sun to lift Cosmos 1 to a higher orbit.

The mission's sponsors at the Planetary Society in Pasadena, California, think Cosmos 1's flight
ultimately will prove the science-fiction conceit that sailing to the stars aboard a light-powered
ship is possible.

"Our role is as the dreamers and instigators behind this spacecraft," Emily Lakdawalla, project
operations assistant, said on Monday.

"It is very promising technology but one that nobody is really pursuing into space. All we are
trying to do is to demonstrate that the technology can work," Lakdawalla said.

The project started as a dream held by Planetary Society founders Carl Sagan, the late science
fiction writer, and Louis Friedman, who proposed sending a solar sail craft to rendezvous with
Halley's Comet in the 1970s when he worked at NASA.

Friedman, the society's executive director, and others believed the impact from a constant stream of
photons bouncing off a huge sail be enough would impel a craft through frictionless space at an
ever-increasing rate of speed.

With sunlight as its only fuel, a solar sail craft could open the farthest reaches of the solar
system to space travel.

Off drawing board
The collapse of the Soviet Union and the need to find commercial uses for Russia's long-range
missiles helped Cosmos 1 get off the drawing board three decades later.

The project was funded mainly by an entertainment company run by Sagan's widow, Ann Druyan, and by
contributions from Planetary Society members and philanthropist Peter Lewis.

Cosmos 1 was built by Russian spacecraft contractor NPO Lavochkin. It will be launched in the tip of
a converted intercontinental ballistic missile that was part of the Soviet Cold War arsenal. The
plan is for it to orbit Earth for at least a month.

The rocket trip and a boost from a "kick motor" will put the 220.5-pound (100 kg) spacecraft into
orbit about 550 miles (885 km) above Earth shortly after 1 p.m. PDT (1800 GMT).

Cosmos 1 will orbit for several days to acclimatize its instruments to the vacuum of space before
its twin sails are deployed via inflatable booms. Mission controls now plan to deploy the sails late
on Saturday.

Each sail is made up of eight triangular blades whose combined structure looks like a disk. The
reflective Mylar sails are about 5 microns thick, or about one-quarter the thickness of a plastic
trash bag.

After it deploys its sails, Cosmos 1 will be visible as it circles the Earth about once every 100
minutes.