Designed as a miniature reconnaissance airplane capable of flying at 40 mph for up to 20 minutes, AeroVironment is building the tiny Black Widow, which ultimately will be able to fly for an hour?or should be, if engineers can figure out how to pack more energy into its batteries. Zipping along at treetop level, the 15-cm-long, 58-gram Black Widow could spot details missed by even the sharpest satellite cameras. AeroVironment, Simi Valley, California. From the book Robo sapiens: Evolution of a New Species, page 158 bottom..