In 1959, 110 military test pilots were invited by the newly-formed National Aeronautics and Space Administration (NASA) to volunteer for the first manned space flight program.
Among those undertaking the series of grueling physical and psychological tests was Alan Bartlett Shepard Jr (pictured top right) - destined to become one of the most important Americans in history.
After being recruited as one of seven Mercury astronauts - along with Virgil Ivan (Gus) Grissom, John Herschel Glenn Jr, Malcolm Scott Carpenter, Walter Marty (Wally) Schirra Jr, Leroy Gordon Cooper Jr and Donald Kent (Deke) Slayton - Shepard was chosen for the first American manned space mission in January 1961.
Had everything gone to plan, Shepard could have been the first human in space. However, unplanned preparatory work delayed his flight on several occasions.
The eventual launch took place on May 5, 1961. Just a month previously, a Soviet cosmonaut named Yuri Gagarin had beaten Shepard to becoming the first person in space.
Nevertheless, on this day in history, Shepard was launched aboard the Redstone rocket into a ballistic trajectory suborbital flight up to an altitude of 116 statute miles.
Unlike Gagarin, whose flight was automatic, Shepard had some control of his spacecraft, Freedom 7, particularly its altitude.
After returning from space, he eventually landed 302 statute miles from his point of launch, along the Atlantic Missile Range.
As the likes of Neil Armstrong and Buzz Aldrin would later experience, Shepard's launch into space and subsequent return was watched live on television by millions of people.
Thereafter, Shepard was celebrated as a national hero. He met with President John F Kennedy and was honoured with parades in Washington, New York and Los Angeles.
Remarkably, Shepard's adventures in space didn't end there - and he would unbelievably top his achievement 10 years later.
In 1971 Shepard and fellow Apollo 14 astronaut Edgar Mitchell becoming the fifth and sixth men to walk on the Moon's surface.
While on the moon, he playfully pulled out a golf ball and hit it across the lunar surface with a makeshift golf club.
Shepard retired from the space program in 1974, also retiring from the Navy with the rank of rear admiral.
Last month, Alan Shepard's Gemini spacesuit auctioned at Regency Superior in California, commanding a final price of $187,200.
Today, space collectibles are among the most cherished and valuable collectibles - and one of the greatest testaments to mankind's bravery outside of war memorabilia.