In this undated photo provided by Sandia National Laboratories, a time exposure, a light-emitting diode, or LED, attached to a self-guided bullet at Sandia National Laboratories shows a bright path during a nighttime field test. (AP Photo/Sandia National Laboratories)
Figuring out how to pack a processor and other sophisticated equipment into a machine gun bullet has been a challenge, but engineers at Sandia National Laboratories say the miniature guidance system they've developed is a breakthrough.