The US Congress on Wednesday will award the nation's highest civilian honor, the Congressional Gold Medal, to four American astronauts including the first man to walk on the Moon, 81-year-old Neil Armstrong.
Other recipients are Buzz Aldrin, 81, who was second man to walk on the Moon, and Michael Collins, also 81, who was the command module pilot for Apollo 11, the first manned mission to the Moon in 1969.
The fourth winner is former senator John Glenn, 90, the first American to orbit the Earth in 1962.
They were given the nod by Congress in 2009 to receive the award, making them the first astronauts ever named to the honor, on what was then the 40th anniversary of the pioneering US mission to the Moon.
Wednesday's ceremony is set for 11:00 am (1600 GMT) at the US Capitol Rotunda.
Past winners of the Congressional Gold Medal, described as the "highest expression of national appreciation for distinguished achievements and contributions," include Myanmar pro-democracy icon Aung San Suu Kyi, the Dalai Lama, Walt Disney, and Pope John Paul II.
Florida Senator Bill Nelson, who initially sought the Congressional recognition for the quartet, said on the eve of the ceremony that lawmakers were likely to vote to approve a NASA budget of 17.8 billion dollars.
"This budget makes a major investment in the next generation of human space flight," he said, describing it as "good news" because it would give more funding toward the James Webb Space Telescope and a rocket for deep space travel.
Armstrong was on Capitol Hill in September, when he told lawmakers that the end of the space shuttle era has left the American human spaceflight program in an "embarrassing" state and urged NASA to return to the Moon.
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