The world's first spacecraft to use a solar sail for propulsion is set to be launched from a submerged Russian submarine on 1 March next year.
The spacecraft uses photons from the Sun to propel it
Cosmos-1 has been built by space advocacy group The Planetary Society and will deploy eight triangular sail blades once it is in space.
Photons from sunlight will push on the spacecraft sails to propel it on the first controlled solar sail flight.
Some hope solar sails will one day help humans travel to the stars.
The US, European, Japanese and Russian space agencies also have solar sail programmes in the offing.
The entire spacecraft has reportedly been completed for under $4m (£2.1m).
Cosmos-1 will be launched into space aboard a modified Volna intercontinental ballistic missile (ICBM) from a submarine in the Barents Sea. Typically, the Volna does not have enough thrust to reach orbit.
But the missile used for Cosmos-1 will have an added rocket engine (kick stage) of a type used to de-orbit satellites.
The kick-stage engine will provide the additional thrust required to get Cosmos-1 into orbit.
Although 1 March is slated as the earliest date for a launch attempt, the mission has a launch period extending from 1 March to 7 April 2005. Ultimately, the launch date will be determined by the Russian Navy.
"This whole venture is audacious and risky," said Bruce Murray, co-founder of The Planetary Society with astronomer Carl Sagan and space scientist Louis Friedman.
A Russian Navy missile has been modified to launch Cosmos-1
"It is a testament to the inspiring nature of space exploration and to the desire of people everywhere to be part of the adventure of great projects."
Solar sails reflect light particles, or photons, from the Sun, gaining momentum in the opposite direction to propel spacecraft forward.
Several days to perhaps a week of checkout is likely - to make sure the spacecraft systems are in good health - before the blades are positioned. The controlled flight might then occur in the second week after launch.
Because solar sails continue accelerating, they could reach distant targets in amazing times.
Sunlight would become too weak beyond the realms of Jupiter but one theory for interstellar travel is to direct lasers at the sails.