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Privately-Funded Spacecraft Spreads Its Solar Sails

  • Reuters

An artist's rendition of LightSail and the Milky Way (Image: The Planetary Society)

An artist's rendition of LightSail and the Milky Way (Image: The Planetary Society)

A privately-funded space project to demonstrate an innovative solar sail passed with flying colors despite a series of near-fatal technical issues, program managers said on Wednesday.

The 11-pound (5 kg) LightSail spacecraft, tucked inside a 4 x 4 x 12-in. (10 x 10 x 3-centimeter) box, hitched a ride into orbit aboard an Atlas 5 rocket carrying the U.S. Air Force's X-37B robot space plane on May 20.

Funded by members of The Planetary Society, a California-based space advocacy organization, LightSail was intended to demonstrate how a tiny motor could unfurl four thin Mylar films into an area as big as a living room.

A follow-on mission planned for late next year would put a similar satellite into a higher orbit so that it could practice a space propulsion technique known as "solar sailing." The idea is to make use of the pressure of photons from the sun against a film to generate forward motion.

"We just could not be more pleased, especially after all the ups and downs that this project has been through," LightSail project manager Doug Stetson told reporters on a conference call.

The Planetary Society attempted a solar sailing demonstration in 2005, but the satellite, flying aboard a Russian rocket, was lost in a launch accident.
In 2010, Japan successfully tested a solar sail that also was embedded with solar cells to generate electricity.

"The idea of sailing on sunlight goes back many, many centuries," Arizona State University planetary scientist Jim Bell told reporters on a conference call.
With the revolution in ultra-small, off-the-shelf satellites known as "cubesats," solar sailing becomes a viable and affordable, chemical-free alternative for low-cost space missions, he added.

LightSail overcame communications problems, software glitches and battery issues before finally unfurling its quartet of sails on Sunday.

"That was some white knuckle time," Stetson said. "We had very limited data to go on.... This has really been a roller coaster ride of emotions, a lot of sleepless nights for the operations and engineering team."

Confirmation, via a spacecraft self-portrait, finally came on Tuesday.

"Getting that beautiful picture of the sail really made the whole thing worthwhile," Stetson said.

Project managers are mulling other tests to put the spacecraft through before it succumbs to Earth's gravity and is pulled back into the atmosphere sometime this weekend.