Solar sail mystery unfurls

Ann Druyan and Bill Nigh as the Cosmos 1 was launched from a Russian submarine. Picture / Reuters

PASADENA - Scientists said they may have detected signals from the world's first solar sail spacecraft, hours after it suddenly stopped communicating following yesterday's launch from a Russian submarine under the Barents Sea.

"Good news," said Bruce Murray, a co-founder of The Planetary Society, which organised the launch. "We are very likely in orbit ... we seem to have a live spacecraft."

The announcement came after an all-day search for Cosmos 1, a US$4 million ($5.6 million) experiment intended to show that a so-called solar sail can use sunlight to fuel space travel.

The initial data reception after it was blasted from earth in a converted Russian Volna ballistic missile was followed by silence.

Backers initially believed the disc-shaped craft either veered off course during its trip into orbit or failed to separate from the Volna rocket.

A 2001 test launch of the solar sails ended in failure because of problems with the launch vehicle separating from the spacecraft.

Mission controllers grew worried after several tracking stations along the path of Cosmos 1's intended orbit failed to pick up signs of the 100kg spacecraft.

A portable tracking station in Russia's Kamchatka peninsula, manned by a volunteer with a laptop and an antenna, picked up Doppler data showing the spacecraft's velocity, but the feed was cut off as a "kick motor" apparently ignited to lift the craft into orbit.

The radio silence extended for more than six hours as mission organisers, operating from the Planetary Society's bungalow in Pasadena, attempted to track the orbiter's expected path.

Another portable tracking station in the Marshall Islands was unable to detect the craft's passage.

Mission officials said radar scans of the area showed no evidence the spacecraft had exploded.

The spacecraft was also not detected by permanent ground tracking stations in Alaska, the Czech Republic or by two stations outside Moscow.

Controllers said Cosmos might have been too low on the horizon for stations to pick up its signal during earlier passes.

The signals were detected in a review of data recorded at ground tracking stations on Russia's Kamchatka Peninsula, Majuro in the Marshall Islands of the Pacific Ocean and at Panska Ves, Czech Republic.

If all went as planned, the spacecraft was to unfurl eight triangular sails, each 15m long and just a quarter of the thickness of a trash bag.

Controlled flight, achieved by rotating each sail to change its pitch, would be attempted early next week. Cosmos 1 was supposed to orbit Earth once every 101 minutes and operate for at least a month.

Solar sails are seen as a means for achieving interstellar flight by using the gentle push from the continuous stream of light particles known as photons from the sun.

Though gradual, the constant light pressure should allow a spacecraft to build up great speed over time, and cover great distances.

Such a craft would not have to carry chemical fuel to propel itself through space, and, according to advocates, would eventually achieve greater speed than a traditional spacecraft.

The technology would suffer, however, as it travelled further from the sun.

The Pasadena-based Planetary Society was founded by the late astronomer Carl Sagan.

The project was also organised by Murray, who is a former director of Nasa's Jet Propulsion Laboratory, and Louis D. Friedman, a JPL veteran.

Funding came largely from Cosmos Studios of Ithaca, New York, a science-based entertainment company that was founded by Sagan's widow, Ann Druyan.

"Whatever we discover from this mission, if it's not a success, we'll still learn from it," she said. "The way to the stars is hard."

Built in Russia by the Lavochkin Association and the Space Research Institute of the Russian Academy of Science, Cosmos 1 was under the control of a mission operations centre in Moscow.

Japan tested solar sail deployment on a suborbital flight and Russia deployed a solar sail outside its old Mir space station, but neither involved controlled flight.

- REUTERS