Two of the astronauts who took part in the first Moon landing four decades ago have called for a manned mission to Mars.
At a rare public reunion of the Apollo 11 crew, Buzz Aldrin and Michael Collins called for an exploration mission to Mars.
The two and fellow mission-member Neil Armstrong, the first man on the Moon, spoke at an event at Washington DC's National Air and Space Museum to mark the 40th anniversary of their mission.
Mr Armstrong said the race to get to the Moon was an "exceptional national investment" for the United States and former USSR.
Elsewhere, 12 Apollo astronauts today reminisced, traded stories and poked fun at each other as the 40th anniversary of the first moon landing and moonwalk approached.
The astronauts, including Mr Armstrong and Mr Aldrin, attended the Dayton, Ohio ceremony in which the National Aviation Hall of Fame presented the Apollo crews with the “Spirit of Flight” award for their courage and dedication.
The crowd of hundreds at the National Museum of the United States Air Force erupted in cheers when a video chronicling the space programme replayed Mr Armstrong’s famous first words after stepping on the moon July 20th, 1969: “One small step for man, one giant leap for mankind.”
“It was spectacular,” Mr Armstrong recalled of gazing at the moon’s surface as he took those first steps.
“Any time you go to a place where everything you see is different than anything you’ve ever seen before in your life, it’s unique and it’s memorable. And that certainly was.”
However, Mr Armstrong said he and Mr Aldrin had little time to savour the experience. “We didn’t rest hardly five seconds when we got a message from Mission Control, saying get on with the next item,” Mr Armstrong said.
Mr Armstrong said he had been a backup on Apollo 8 and that when he wasn’t needed was asked if he wanted to be on the third mission down the line — what turned out to be the fateful Apollo 11 mission. He said it was difficult to predict the exact mission of succeeding flights.
“We knew we had a chance at landing, but it was by no means certain,” he said.
As they sat together on the stage, the astronauts joked and bantered with each other.
Astronaut Eugene Cernan, the last man to walk on the moon, also flew in the Apollo 10 flight preceding Mr Armstrong’s. He joked that his job was to paint a white line to the moon that Apollo 11 could follow.
“Everyone knew Neil could land on the moon, but we didn’t have a lot of confidence Neil could find it,” Mr Cernan quipped.
“I’ve been listening to that for 40 years, and this is not the time to change my position,” Mr Armstrong shot back, drawing laughs from the crowd.
But the first lunar landing was a serious matter for the astronauts and those in mission control. When the designated landing zone proved to be too rocky, Mr Armstrong had to burn fuel from a diminishing supply to find a suitable place to touch down.
“I can’t say it was panic, but it was a lot of attention to detail in mission control,” said Charles Duke, who was at mission control at the time.
“The fuel level is going down, down, down, and things are getting real tense.” When there were only 30 seconds of fuel left, “it got dead silent”.
Agencies