Sent up two monkeys, First to land on the Moon.
Jan. 31 - Explorer 1, the first American satellite to reach orbit, is launched. It carried scientific equipment that lead to the discovery of the Van Allen radiation belt.
Mar. 5 - Explorer 2 is launced but it fails to reach orbit.
Mar. 17 - The Vanguard 1 satellite is launched. It continues to function for 3 years.
Oct. 1 - The National Aeronautics and Space Administration (NASA) is formed, it replaces the National Advisory Committee on Aeronautics (NACA).
1951 April 11 - Truman fires MacArthur
1952 A-bombs developed by Britain
1963: July : Nuclear Test Ban Treaty ratified
1965 July : Announcement of dispatching of 200,000 U.S. troops to Vietnam
Dropped the Atomic bomb on Hiroshima
Sputnik Satellite, A dog, and Two probes were sent up into space
Oct. 4 - USSR launches Sputnik 1.
Nov. 3 - USSR launches Sputnik 2 which carried a small dog named Laika into orbit.
May 15 - Sputnik 3 is launched.
Jan. 2 - Luna 1 is launched by the USSR. It is the first man made object to orbit the Sun.
29 August : Russia tested its first atomic bomb
June 24: Korean War begins. Stalin supports North Korea who invade South Korea equipped with Soviet weapons
1968 August : Soviet Red Army crush Czechoslovakian revolt
1989 January : Soviet troops withdraw from Afghanistan