As an estimated 500 millionagnificent desolation" of the lunar landscape, never before witnessed in close up on Earth.

Only 12 earthlings have walked on the surface of the moon, the Earth's lone mysterious statellite, which has fuelled our dreams and imaginations since the earliest humans walked the planet.

And the last moonwalk was already more than a generation ago in 1972.

But at the height of the Cold War, the Apollo program succeeded in proving America's dominance in the space race. Planting an American flag on the surface of the moon in 1969 scored major morale-boosting points over the Soviet Union.

The Apollo program, which led to six succesful moon landings between 1969 and 1972, had begun eight years earlier in 1961 when then president John F. Kennedy threw down a bold challenge to Congress to put a man on the moon within the decade.

"I believe that this nation should commit itself to achieving the goal, before this decade is out, of landing a man on the moon and returning him safely to the Earth," Kennedy said.

The decision to shoot for the moon was above all a political one, said John Logsdon, curator and expert at the National Air and Space Museum.

The Soviet Union had been the first nation to put a satellite into orbit in 1957, with the launch of the Sputnik, and in 1961 Yuri Gagarin became the first man to fly in space.

"The Soviet Union had defined space achievement the measure of power and desirability of a modern society and president Kennedy decided that leaving a dramatic space achievement only to the USSR was not in the U.S. interest," Logsdon told reporters.

The space race became symbolic of the Cold War battle for dominance between competing ideologies and polarized world powers.

In 1970 just months after the lunar landings, Soviet dissident Andrei Sakharov in an open letter to the Kremlin wrote that America's ability to put a man on the moon proved the superiority of a democracy.

"NASA had been studying a mission to the moon prior to Kennedy's decision and had concluded that there was no major technological barrier," Logsdon said.

"On the other hand, there was little experience in building the kind of large and complex systems required to carry out the mission."

Thanks to America's growing prosperity and their scientific and technical achievements, the U.S. swiftly put into motion the Apollo program. In 1969 it was estimated at some US$25 billion - about US$115 billion at today's value, or more than six times NASA's current budget.

But the Apollo program hit some setbacks. In 1967, three astronauts were killed in an accident on the ground.

Then in December 1968 Apollo 8 blasted off, and America's first manned flight around the moon took place.

Six months later it was followed by Apollo 10, a lunar reconnaissance trip with three astronauts on board.

Then on July 16, 1969, Armstrong, the mission commander, Aldrin and Mike Collins settled themselves into the orbiting command module Columbia on the Apollo 11, which was taken up into space perched on the Saturn V rocket.

The huge rocket, towering some 111 m high, lifted off from the Kennedy Space Center at 9:32 p.m. Taiwan time.

Four days later, Armstrong manually maneuvered the lunar module, dubbed "Eagle," to land on the moon's Sea of Tranquility.

"Houston, Tranquility Base here. The Eagle has landed," he told mission control in Houston, Texas.

At 10:50 a.m. Taiwan time, the 38-year-old Armstrong left the module and stepped down a short ladder. With a small leap, he landed on the moon's surface at 10:56 a.m. and 48 seconds Taiwan time.

Twenty minutes later he was joined by the 39-year-old Aldrin.

Together they spent 21 hours on the moon's surface, planting the American Stars and Stripes and a steel plaque bearing a message of peace.

They collected some 21 kg of rocks and then returned to Columbia where Collins was awaiting them for a triumphal return to Earth.

They landed back on July 24, ditching into the Pacific Ocean.