From Popular Science: NASA’s new heavy lift rocket isn’t the only massive space propulsion system the agency has in the works. The largest solar sail the solar system has ever known is headed to the launchpad in 2014 on a mission that will eventually take it nearly 2 million miles from Earth. The demonstrator mission aims to show that the technology lessons learned from NASA’s smaller NanoSail-D mission and JAXA’s IKAROS solar sailing space vehicle can be leveraged into a large-scale space-traversing propellantless propulsion system.