The New Mexico Proving Grounds (NMPG) was constructed concurrently with the development of the Albuquerque Army Air Base and the activities at the old Oxnard Field. It was built to the south to serve as the base for testing the top-secret proximity fuze, a device that played an important role in defeat of the German Vergeltungswaffe (V-1) rocket. The proximity fuze, a weapon that was later dubbed by the media as the second most important one developed during the war. By war's end, nearly 50,000 acres had been acquired for the NMPG, this acreage is to the south of the runway and main base that today makes up the greatest portion of Kirtland AFB.