I have learned to use the word "impossible" with the greatest caution.

In a face-to-face meeting with Herb York at the Pentagon von Braun made it clear he would go to NASA only if development of the Saturn was allowed to continue. Initially he was recruited to the U. The fourth stage provided acceleration to lunar escape velocity while the fifth stage would be responsible for a deceleration during return to the Earth to a residual speed that allows aerocapture of the spacecraft ending in a runway landing much in the way of the Space Shuttle.

In 1975 he received the National Medal of Science. In his 20s and early 30s von Braun was the central figure in Germany's rocket development program responsible for the design and realization of the V-2 combat rocket during World War II. Von Braun worked on the United States Army intermediate range ballistic missile (IRBM) program before his group was assimilated by NASA.