Solar Sail Spacecraft Begins Test Voyage in Orbit
CAPE CANAVERAL, Fla., May 22, 2015 — A small box launched into space Wednesday will soon blossom into a 32-m2 spacecraft designed to sail on sunlight.
The flight is a test of The Planetary Society’s LightSail, which the organization said could change how satellites and even larger spacecraft move around the solar system.
LightSail isn't high enough to escape Earth's atmospheric drag and thus will not demonstrate controlled solar sailing. Instead, it is expected to go through a testing period of about four weeks, after which it will deploy its four solar sails so crews on the ground can study their behavior in low-earth orbit.
"While we celebrate this step, LightSail's biggest tests are still ahead," said The Planetary Society's CEO Bill Nye. "Over the next days, we will be monitoring our CubeSat as we prepare for the big show: the day LightSail deploys its super shiny Mylar sails for flight on sunlight. Stay tuned; the best is about to happen."
Solar sailing works by using sunlight for propulsion. When solar photons strike LightSail's reflective sails, their momentum is transferred to the spacecraft, gradually accelerating it through space. While the push from photons is miniscule, it is continuous and unlimited. Solar sails can eventually reach greater speeds than those obtained from chemical rockets.
LightSail is packaged into a small spacecraft called CubeSat. CubeSats have made low-cost space missions a reality for universities and research groups.
Providing propulsion for these tiny satellites has been a challenge, however. The Planetary Society hopes LightSail will demonstrate the viability of solar sailing for CubeSats.
Its four triangular sails are each 4.5 μm thick. Extended on four tape measure-like masts, they are designed to spread out into a square roughly the size of a boxing ring.
LightSail was launched into orbit aboard a United Launch Alliance Atlas V rocket from Cape Canaveral Air Force Station. The spacecraft is part of a secondary payload, dubbed UltraSat, aboard the U.S. Air Force mission AFSPC-5.
During the current test flight, key images and data on the spacecraft's performance will be sent to ground stations at California Polytechnic State University and the Georgia Institute of Technology. This data will inform a second mission planned for higher orbit next year.
The second LightSail will be packaged inside a spacecraft called Prox-1 built by students at Georgia Tech. The spacecraft duo will be launched aboard a SpaceX Falcon Heavy rocket to an orbit of about 720 km.
The $5.45 million project is being funded by Planetary Society and donations to a Kickstarter campaign started earlier this month by Nye and astrophysicist Neil deGrasse Tyson, a member of The Planetary Society's board of directors.
The spacecraft was designed by Stellar Exploration Inc., in San Luis Obispo, Calif. The lead contractor for integration and testing was Ecliptic Enterprises Corp. of Pasadena, Calif. The LightSail project is managed by Doug Stetson, founder and principal partner of Space Science and Exploration Consulting Group.
For more information, visit sail.planetary.org.
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