Nasa is preparing to celebrate the 50th anniversary of the Apollo 11 moon landing, which saw Commander Neil Armstrong become the first person to step onto the lunar surface.
The mission saw three astronauts, Armstrong, Buzz Aldrin and Michael Collins, launched into space on July 16 1969, marking one of humanities biggest moments in space exploration.
People across the globe watched in amazement as Armstrong and Aldrin walked across the lunar surface into the early hours of July 21, taking photos, collecting samples, planting a US flag and taking a call from then-president Richard Nixon.
“That’s one small step for man, one giant leap for mankind,” Armstrong famously said.
Speaking about the mission 50 years on, Aldrin said: “To me, it was the dream we had all signed up to chase, what we had imagined, worked and trained for, the apex of national service to a country we unabashedly loved, the height of aviation and exploration.
“To my colleagues, as to me, Apollo was a mission of enormous national security importance – a way to prove America’s exceptional nature, pointing the way forward for mankind in space and forward to peace here on Earth.
“I sometimes think the three of us missed ‘the big event’.
“You smile, but while we were out there on the moon, the world was growing closer together right here.”
The last time astronauts walked on the moon was during Apollo 17, in 1972.
Today there is increased interest in returning, with Nasa aiming to put feet on the moon by 2024 and multinational plans to build a space station around the moon in the future.