After lots of talk and testing, Japanese researchers are ready to go space sailing. Japan Aerospace Exploration Agency (JAXA) announced its intention to launch its first "space yacht" propelled by solar sails into the heavens on May 18. Ikaros -- the Interplanetary Kite-craft Accelerated by Radiation of the Sun -- will cruise through the solar system powered by solar particles that bounce of its giant, ultra-thin sails.
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.