NASA has announced plans to fly its own solar-sail research craft. This first experiment is more about validating how to unfold the sail than it is about actually toodling around the solar system via a special sort of wind power. This is more important than it might at first seem. Unfolding something the thickness of tissue paper after it's been packed into the nosecone of a rocket and flung into space isn't one of the easiest of engineering tasks, donchaknow?