Spacecraft headed to Mars or beyond may harness a new source of propulsion that could refuel almost anywhere in the solar system. Last week, the VASIMR prototype plasma rocket achieved 200 kilowatts of power, the milestone the team was striving for. Now they are beginning development of a flight-capable version, slated for launch in 2013.
Five amazing, clean technologies that will set us free, in this month's energy-focused issue. Also: how to build a better bomb detector, the robotic toys that are raising your children, a human catapult, the world's smallest arcade, and much more.