Impossible Target: America - Adolf Hitler's 4 Plans to Attack the United States
Silbervogel, Amerikabomber, Project Pastorious, and rocket U-boats were part of Adolf Hitler's plan to attack the USA. None of the plans succeeded. Although, Silbervogel and rocket U-boats paved the ground for the development of a space shuttle and submarines with ballistic missiles, respectively.
Source: historyofyesterday.com