Copyright 2011, The Associated Press
In this May 5, 1961 image released by NASA, the Freedom 7 manned by U.S. astronaut Alan B. Shepard Jr., is seen during liftoff from the Kennedy Space Center at Cape Canaveral, Fla. Shepard became the first astronaut to man a spacecraft in orbit . NASA is celebrating the 50th anniversary of the U.S. human flight with several ceremonies and a parade. The U.S. Postal service will unveil two new stamps, one commemorates NASA's Project Mercury and Shepard's history launch and the other honor's NASA's Messenger, which became the first spacecraft to orbit the planet Mercury. (AP Photo/NASA, HO)