NASA will launch a solar sail this year, to explore options for propulsion without using propellants:
http://www.wired.co.uk/news/archive/2013-03/26/solar-sail-sunjammer
NASA will launch a solar sail this year, to explore options for propulsion without using propellants:
http://www.wired.co.uk/news/archive/2013-03/26/solar-sail-sunjammer