July 1969: American astronaut Neil Alden Armstrong, the first man to walk on the moon as commander of the Apollo 11 lunar mission.

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One of the few photographs of Neil Armstrong on the moon shows him working on his space craft on the lunar surface.

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Neil Armstrong steps into history July 20, 1969 by leaving the first human footprint on the surface of the moon.

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Astronaut Neil Armstrong, commander of Apollo 11, testifies before the House Science, Space, and Technology Committee about human space flight on Capitol Hill September 22, 2011 in Washington, DC.

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New York City welcomes the Apollo 11 crew in a showering of ticker tape down Broadway and Park Avenue August 13, 1969 in a parade termed as the largest in the city's history. Pictured in the lead car, from the right, are astronauts Neil A. Armstrong, commander; Michael Collins, command module pilot; and Edwin E. Aldrin Jr., lunar module pilot.

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Left to right, are Neil A. Armstrong, commander; Michael Collins, command module pilot; and Edwin E. Aldrin Jr., lunar module pilot, crew of the Apollo 11 lunar landing mission.

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Retired NASA astronaut Neil Armstrong (L), commander of the Apollo 11 mission and the first man to walk on the moon, and retired astronaut Capt. Eugene Cernan (C), commander of Apollo 17 mission, testify on Capitol Hill May 12, 2010 in Washington, DC.

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Retired NASA astronaut Neil Armstrong (L), commander of the Apollo 11 mission and the first man to walk on the moon, listens as retired astronaut Capt. Eugene Cernan (R), commander of Apollo 17 mission, testifies on Capitol Hill May 12, 2010 in Washington, DC.

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Astronaut Neil Armstrong, commander of Apollo 11 and the first human to walk on the moon, testifies before the House Science, Space, and Technology Committee about human space flight on Capitol Hill September 22, 2011 in Washington, DC.

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Astronaut Neil A. Armstrong poses for a portrait July 1969. Armstrong was the Commander of Apollo 11 Lunar Landing Mission. The 30th anniversary of the Apollo 11 Moon landing mission is celebrated July 20, 1999.

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Portrait of Neil Armstrong in 1959, ten years prior to the Apollo 11 mission in which he became the first human to set foot on the moon.

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Astronaut Neil Armstrong.

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Astronaut Neil Armstrong, the first man on the moon, smiles during the kick-off celebration ceremony of the Centennial Of Flight exhibit honoring the 100th anniversary of the Wright brothers' historic flight at Rockefeller Center July 29, 2003 in New York City.

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U.S. President Barack Obama poses for photographs with Apollo 11 astronaut Neil Armstrong, the first man on the moon, in the Oval Office at the White House July 20, 2009 in Washington, DC.

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Retired NASA astronaut Neil Armstrong (L), commander of the Apollo 11 mission and the first man to walk on the moon, testifies on Capitol Hill May 12, 2010 in Washington, DC.

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