jan_jes writes to note that The Planetary Society is attempting to crowdfund its own version of the light-powered space-craft popularized by Carl Sagan as a "solar sailer." (YouTube video, with the Society's CEO Bill Nye.) The current model is a CubeSat no bigger than a breadbox with four sails. If the team manages to raise enough money, LightSail will be sent to orbit aboard a SpaceX Falcon Heavy rocket in 2016. LightSail will be released into an orbit with an altitude of 720 kilometers (450 miles), high enough to escape most of the planet's atmospheric drag. Their crowdfunding goal has been far surpassed (more than $476,000 at this writing), but more can't hurt; maybe NASA could use some of the surplus.