He may have been 23 days short of first place -- Yuri Gagarin beat him -- but Alan Shepard still holds a place in history.

NASA is celebrating the 50th anniversary of Shepard's trip into space, when he became the first American (and second human) to reach outer space. As part of the celebration, the space agency unveiled two stamps, with one featuring images of Shepard, the Freedom 7 capsule and the historic launch. The other shows NASA's Messenger probe, which recently reached Mercury to become the first spacecraft to orbit the planet. NASA also plans on recreating Shepard's flight and recovery, as well as a tribute to his contributions as a moonwalker on the Apollo 14 lunar mission.

May 5, 1961, was a good day. When Alan Shepard launched toward the stars that day, no American had ever done so, and the world waited on pins and needles praying for a good outcome. The flight was a great success, and on the strength of Shepard's accomplishment, NASA built the leadership role in human spaceflight that we have held ever since, NASA administrator Charles Bodden said in a blog.       

The mission, dubbed Mercury-Redstone 3, was made 23 days after The Soviet Union's Yuri Gagarin became the first man in space. The closeness of Shepard and Gagarin's trips into space reflect the immense competition at that time between the USSR and the United States in space exploration. Gagarin and Shepard's trips into space were the precursors to a decade of space exploration, which was capped off by man's first steps on the moon, by Neil Armstrong in 1969.

Shepard's initial mission only lasted 15 minutes and 28 seconds -- a blip in comparison to today's 15-day missions. He launched from Cape Canaveral, Fla., and re-entered the atmosphere 190 nautical miles south of there and landed in the water. When he returned to the U.S., Shepard was lauded as an American hero and given parades in New York City, Washington D.C. and Los Angeles.

Shepard, who died in 1998 at the age of 74, started out his life, like many of his space travelling brethren, by flying planes for the military. After a lengthy career in the Navy, he was one of 110 military test pilots selected by the newly-formed NASA to fly the first manned flight into space.

After Mercury and Freedom 7, Shepard went on to be the chief astronaut of NASA's Project Gemini mission. He had to be removed because he developed Ménière's disease, but did get a chance at redemption with Apollo 14. As part of that mission, Shepard became the fifth man to have walked on the moon. He is widely remembered as the astronaut who played golf on the moon.

The inspiration that has created generations of leaders to enlarge our understanding of our universe and to strive toward the highest in human potential was sparked by those early achievements of our space program. They began with Freedom 7 and a daring test pilot who flew the ultimate experimental vehicle that May day 50 years ago, Bodden said.

NASA has recently begun talking about making a return to the moon, this time with companies from the private sector leading the way in spacecraft development.

Take a look photos of Alan Shepard: The First American In Space

Follow Gabriel Perna on Twitter at @GabrielSPerna