Solar Sails a Reality!

The Planetary Society, a non-profit club with the mission statement to explore other planets, is sponsoring the first ever solar sail, and it's launching tomorrow! Much like a normal sail uses the push of the air to propel a boat, a solar sail uses the push of photons (light particles) to propel the payload (spaceship). I haven't yet heard proposals of "tacking against the solar wind"; I think the light pressure is too low to allow this, but perhaps in the future we'll figure out how. In other words, it's a one-way trip away from our sun. The payload has to be superlight, so the ship will not be carrying any fuel to return--we don't yet know how to get such ships back!

Update!
Apparently some amount of "tacking against the sun" is possible. I think the plan is to keep Cosmos 1 in orbit around the Earth, and use tacking to alter its orbit occasionally as a proof-of-concept.


BBC