Launched three days before the first Apollo lunar landing mission, the Soviet Luna 15 marked a Soviet-American intersection in space.
The Navaho missile never flew, but the technology it spawned shaped the nation's first generation of intercontinental ballistic missiles.
Physical fitness and a sound mind were only part of the "right stuff" for NASA's very first astronaut.
Since 1937, the Wright brothers' first flight has been contested by supporters of Gustave Whitehead. And they may have a case.
On January 18, 1965, Boris Volynov nearly died on his way home form orbit, and the Soviets kept it secret for over 30 years.
Cosmonaut Alexei Leonov became the first man to walk in space in 1965, but the mission almost killed him.
On September 9, 1942, Japan tried and failed to bring WWII to the continental United States.
Gagarin's background made him stand out from his cosmonaut class of brilliant and talented pilots, and helped him become the first human in space.
John Glenn's Friendship 7 flight was just what the Soviet Union needed to regain their momentum in space.
For a brief moment on John Glenn's orbital flight, NASA's first, it looked like the astronaut wouldn't make it home alive.