The civilian program solely authorized by Eisenhower to launch the first earth satellite. The Vanguard was developed from the civilian Viking sounding rocket. A secret political agenda was to establish the right of orbital overflight of the Soviet Union, either by flying a purely civilian satellite, or by letting the Russians orbit the earth first. Sputnik was first, the Vanguard failed, and facing the tremendous public impact of Sputnik - which surprised Eisenhower, Khrushchev, and Korolev - Eisenhower authorized Von Braun to launch Explorer atop a Jupiter-C Redstone - almost two years after it was first possible. The Vanguard went on to a less-than-thrilling launch record, but its second stage was developed into various Able upper stages used on the Thor and Atlas for years to come.
