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How Solar Sail Technology Works


 Solar sails will use the sun's energy to propel spacecraft. 
Solar sails will use the sun's energy to propel spacecraft. 
Photo courtesy The Planetary Society

In the 1970s, NASA scientists proposed sending a probe to Halley's comet that would be propelled by the pressure of sunlight against a giant solar sail. Although the proposal was rejected as being too risky and unproven, the idea of solar-sail-propelled spacecraft has endured. Numerous developments and tests of solar-sail materials have been conducted over the years, but no one had designed, successfully launched and sailed such a spacecraft.

In June 2005, The Planetary Society, in collaboration with several Russian space organizations, will launch the Cosmos-1 spacecraft into Earth orbit.

What is a solar sail? How can you use sunlight to move a spacecraft in outer space? In this article, HowStuffWorks will show you how solar sail technology works, take an in-depth look at the Cosmos-1 mission and find out what solar-sails mean for future space travel.