Solar Sail

At http://science.nasa.gov/science-news/science-at-nasa/2011/24jan_solarsail/ there is a picture of the solar sail. NASAs Nano Sail-D satellite has unfurled a gleaming sheet of space age fabric 650 km above the earth. The idea is to clear up near space. Drag sails, it is hoped, will become standard satellite fixtures so that when missions come to an end the sail can be deployed for its return to the surface via aerodynamic drag, harmlessly disintegrating in the atmosphere before it reaches the ground.