The proximity fuse was a type of fuse attached to artillery shells, making them explode within the proximity of a target, rather than on impact. Testing of the proximity fused anti-aircraft shells was carried out from Kirtland Field as early as 1943. On a certain desert mesa nearby, the army suspended aircraft with "the tallest wooden towers in the world" to fire the shells at them. The fuses proved to be a major success not only in the Pacific Theater, where they were used with devastating effect against Japanese aircraft, but in the Ardennes during the Siege of Bastogne.