The first man to walk on the moon, Neil Armstrong, has died at the age of 82.
Armstrong was commander of the three-strong team of astronauts on Apollo 11 - NASA's first mission to the surface of the moon.
An estimated 600 million people - a fifth of the world's population - watched and listened to the first moon landing, the largest audience for any single event in history.
He underwent a heart-bypass surgery earlier this month to relieve blocked coronary arteries.
ITV News' Washington Correspondent Robert Moore reports:
Armstrong's words, uttered just before taking his first step on the moon, form one of the most famous phrases of all time:
He and Edwin "Buzz" Aldrin spent almost three hours on the lunar surface, collecting samples, conducting experiments and taking photographs.
Here is the original footage of the first walk on the moon:
The moonwalk marked America's victory in the Cold War space race that began on October 4 1957 with the launch of the Soviet Union's satellite Sputnik 1.
Apollo 11 pilot Michael Collins, who was part of the historic moon-landing mission, paid tribute to his former colleague saying: "He was the best, and I will miss him terribly."
Edwin 'Buzz' Aldrin, who walked on the moon with Armstrong, told BBC News he will remember him as "a very capable commander and a leader of a world achievement that will be recognised, I think, until man sets foot on the planet Mars".
Armstrong was born in Wapakoneta in Ohio on August 5, 1930.
He flew Naval fighter jets from 1949 to 1952. During one flight over North Korea in 1951, the right wing of his jet clipped a cable wire. He managed to fly to friendly territory before ejecting.
Armstrong joined the National Advisory Committee for Aeronautics (NACA) - the precessor of NASA - in 1955 where he served as an engineer, test pilot, astronaut and administrator for the next 17 years.
Armstrong transferred to astronaut status in 1962. He was assigned as command pilot for the Gemini 8 mission in 1966, which led to the first successful docking of two vehicles in space.
As spacecraft commander for Apollo 11, he headed the first manned lunar landing mission.
The Apollo 11 moon mission turned out to be Armstrong's last space flight.
The following year he was appointed to a desk job, being named NASA's deputy associate administrator for aeronautics in the office of advanced research and technology.
In this position, he was responsible for the coordination and management of overall NASA research and technology work related to aeronautics.
He left NASA a year later to become professor of aerospace engineering at the University of Cincinnati - a post be held from 1971 to 1979.
During the years 1982 to 1992, Armstrong was chairman of a company called Computing Technologies for Aviation.
He is survived by his wife, his two sons, a step son and step daughter, 10 grandchildren and a brother and a sister.