U.S. lawmakers have awarded the nation's highest civilian honor, the Congressional Gold Medal, to four of the most celebrated American astronauts.

The recipients include the first men to walk on the moon, Neil Armstrong — who achieved the milestone first — and Buzz Aldrin, who was second.

Other honorees are Michael Collins, the command module pilot for that 1969 moon mission, known as Apollo 11, and former Senator John Glenn, who in 1962 became the first American to orbit the Earth.

The four men are the first astronauts to receive the Congressional Gold Medal.

Speaking at Wednesday's ceremony at the U.S. Capitol building, the head of the U.S. space agency NASA praised them for their bravery and sense of duty and said they “changed the course of history.”

House Democratic Leader Nancy Pelosi hailed the awards as a tribute to the United States' leadership. She said the astronauts ensured the U.S. was first in science, technology and innovation and said that spirit must be sustained today.

Past winners of the Congressional Gold Medal include the Dalai Lama, Burmese pro-democracy leader Aung San Suu Kyi and Pope John Paul II.