Bat

The ASM-N-2 Bat was a United States Navy World War II radar-guided glide bomb which was used in combat beginning in April 1945. It was developed and overseen by a unit within the National Bureau of Standards (which unit later became a part of the Army Research Laboratory) with assistance from the Navy's Bureau of Ordnance, the Massachusetts Institute of Technology, and Bell Telephone Laboratories. It is considered to be the first fully automated guided missile used in combat.