The radio-controlled sphere, roughly the size of a basketball, was built for search and rescue operations: to fly in and out of buildings weakened by earthquakes or other natural disasters, using its onboard camera to transmit live images of whatever it sees. The black, open-work ball looks like a futuristic work of art, but it can hover for up to eight minutes and fly at 60 km (37 miles) an hour - although it does slow down for open windows. Fumiyuki Sato, at the Japanese Defense Ministry’s Technical Research and Development Institute, invented and built the vehicle for roughly 110,000 yen ($1,390) with parts purchased off the shelf at consumer electronics stores. Measuring 42 cm, it zips through the air, glides smoothly around corners, and negotiates staircases with ease, emitting a soft hum.