, WASHINGTON, Jul 20 – The Apollo 11 astronauts who were the first to land on the Moon 40 years ago, have urged Americans to set their sights on Mars.
Neil Armstrong and Michael Collins, both 78, and Edwin "Buzz" Aldrin, 79, went to the National Air and Space Museum on Sunday and used the rare appearance together to press calls to head for new frontiers in space.
Armstrong paid tribute to US physicist Robbert Goddard, who developed the liquid-fuel rocket engine in the 1920s.
He said that the Apollo 11 mission in 1969 was part of the Cold War between the United States and the Soviet Union, as the rival powers sought to establish themselves in outer space.
But he said the rivalry served a valuable purpose.
"It was the ultimate peaceful competition: USA versus USSR. It was intense," he recalled. "It did allow both sides to take the high road, with the objectives of science and learning and exploration."
He added that eventually, the race provided a mechanism for laying the foundation of cooperation between Russia and the United States.
"In that sense, among others, it was an exceptional national investment for both sides," Armstrong concluded.
Aldrin urged Congress and the American people to use the memory of Apollo 11 as inspiration to prepare for a space journey to Mars.
"Apollo 11 was a symbol of what a great nation and a great people can do if we work hard and work together," he said.
"America, do you still dream a great dream? Do you still believe in yourself?" he went on to ask. "I call on the next generation and our political leaders to give this answer: Yes We Can!"
The ceremony was attended by about 500 people, including future NASA administrator Charles Bolden, a former astronaut.
But hundreds of those who couldn’t get the tickets, which had been distributed through a lottery, camped outside the lecture hall in the museum, that has on display the Apollo 11 command module and a replica of the Russian-made Sputnik satellite.
President Barack Obama will meet with the Apollo 11 crew Monday to commemorate the Moon landing and possibly discuss the future of space exploration.