Shepard, 74, died Tuesday at a California hospital, where he had been receiving treatment for leukemia. One of the revered original seven Mercury astronauts named by NASA in April 1959, Shepard become one of only 12 Americans to walk on the moon.
On Wednesday, the National Archives made public diary notes written by Kennedy's secretary, Evelyn Lincoln, that indicate the president was afraid the American public would be traumatized if Shepard's rocket blew up during the launch. But, after receiving assurances from James Webb (then NASA chief), President Kennedy went ahead with the live telecast.
Daniel Goldin, the current administrator of NASA, said: "[Shepard] crawled on top of that rocket that had never before flown into space with a person aboard and he did it. That was an unbelievable act of courage."
Alan Shepard aboard Freedom 7 in 1961. (NASA)
Ten years later, after overcoming a serious ear infection that lingered for six years, Shepard returned to space for his second and last flight as commander of Apollo 14 on Jan. 31, 1971.
Shepard spent 33 hours on the moon during the third lunar landing mission and became the only lunar golfer, playfully whacking golf balls with a six-iron.
Although Soviet cosmonaut Yuri Gagarin beat Shepard into space by 23 days, Shepard's 1961 flight marked the beginning of the infant U.S. space program. He prophetically called that first flight "just the first baby step, aiming for bigger and better things."
On the historic launch morning, Shepard, and the nation, waited impatiently for more than four hours as NASA corrected problems with an electrical system, a ground computer and the rocket's fuel pressure. It was the second launch attempt; the first one three days earlier was foiled by storms.
Shepard training for Apollo 14. (NASA)
In an interview 30 years later, Shepard looked back on his historic Mercury flight, which he said he considered the most exciting point of his career, and marveled that the U.S. space program had encountered only two fatal accidents up to that time.
"Thirty years ago, the large percentage of population thought we were crazy sitting on the top of a rocket and allowing ourselves to be thrust into space," Shepard recalled. "There was a lot of doubt...especially from some of the more learned members of the medical community who thought that man shouldn't be in space. It wasn't his place to be there."
In the years between his Mercury and Apollo missions, Shepard headed NASA's astronaut office and began investing in banks, oil wells, quarter-horses, and real estate.
Retiring from the space agency and from the Navy as a rear admiral in 1974, he became a millionaire as a developer of commercial property, a partner in a venture capital group, a director of mutual fund companies, and president of a beer distributorship, among other interests. Shepard also was president of the Mercury Seven Foundation, which raises money for science and engineering scholarships.
Shepard was a native of East Derry, N.H, and son of a banker.
He was graduated from the U.S. Naval Academy in 1944 and saw World War II action in the Pacific aboard the destroyer Cogswell. He earned his aviator's wings after the war and became a test pilot before his astronaut selection.
After his second flight, Shepard served as a delegate by presidential appointment to the 26th United Nations General Assembly in 1971. He continued as chief of the National Aeronautics and Space Administration astronaut office from June 1971 until August 1974, when he retired.
His awards include the Medal of Honor, for space, in 1979.
From the time of his first flight, Shepard has remained a fierce avocate of the space program. Speaking about how space flight has changed since his Mercury mission, Shepard told Zahn: "It's exciting for youngsters today, just as it was for us. And it's exciting for the youngsters of tomorrow."
Shepard is survived by his widow, Louise, three daughters, and six grandchildren.
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