The Air Force recently caused a stir online after it announced it had used B-2 Spirit bombers to drop the Massive Ordnance Penetrator (MOP) on underground Houthi targets in northern Yemen. The move put both the bomb and the B-2 Spirit Bomber in the spotlight. But what aircraft can carry the United States Air Force’s Massive Ordnance Penetrator (MOP) – designed to penetrate and destroy the deepest of military targets hidden underground?