NASA's Solar Sail... Feb 21, 2006 1:21:47 GMT -6
Post by Chicago Astronomer Joe on Feb 21, 2006 1:21:47 GMT -6
Solar Sail Plans from NASA
Solar sails are a creative and unique way to harness the sun's energy for transportation, requiring no other fuel. Solar sails act just as the name implies: They are a physical sail, pushed by the sun's energy. The sun constantly spews out a high-energy stream of photons. (Photons create the images "caught" by camera film, digital camera CCDs, and the rods and cones in our eyes. "Photograph" and "photon"... It's not a coincidence. In fact, a solar sail is sometimes called a "photon sail". But for this article, the literal - and perhaps more appropriate - name loses out to the conceptual one: Photon sails are out, and we'll stick with "solar sails".
The sun shines, spraying photons in all directions. The solar sail is just a large panel, highly reflective and very lightweight. The force of the photons pushes the against the solar sail. The sail is attached to a spaceship (the green pickle-like thing above), and the force of the photons moves it away from the sun. The direction of movement can be changed by changing the angle of the solar sail. There's not much to it, apart from mind-melting high-level mathematics needed to steer the thing, designing an ultra-light yet strong frame, and knowing how to manage the gigantic sail itself. A fairly simple concept, but executing it requires heavy brainpower.
Here is some background info on the effoerts from NASA and their Solar Sail projects.
It's a shame that The Planetary Societies Solar Sail failed. I anticipate the next ones.