One warning light is all it takes to ground a plane. Age-related corrosion is often the culprit. Airplanes also have mileage-based maintenance checks, so if a plane has just passed the mark (or will very soon), an airline may cancel its next flight to be safe.
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.