But in real life Hitler began production of the V2 (the worlds for ICBM though it never worked) towards the middle of WW2 slowed their devealopment but then towards the end he started them up again
Its predecesor was the V! in use by the germans to slowly cripple the enemy in WWII in the 1939-1942 period. It was still used until the defence of the Bastogne