The Bumper program to produce and launch a two-stage combination of the V-2 and WAC Corporal rockets was conceived in July 1946 by Colonel Holger N. Toftoy.[3] Both the WAC Corporal and the V-2 had been extensively tested at White Sands Proving Grounds, the WAC Corporal's launch series occurring in late 1945/early 1946 and the V-2 launches beginning March 15, 1946.[4]: 235–237