The cremated remains of legendary American astronaut Neil Armstrong were scattered at sea Friday, in a ceremony aboard a US aircraft carrier paying final tribute to the first man to set foot on the moon, NASA said.

US Navy personnel carried Armstrong's remains to the Atlantic Ocean one day after a somber memorial ceremony at the Washington National Cathedral for the famously reserved Apollo 11 commander, who died August 25 at the age of 82.

Armstrong's widow Carol was presented an American flag at the ceremony aboard the USS Philippine Sea that included a bugler and rifle salute.

"Neil will always be remembered for taking humankind's first small step on another world," NASA Administrator Charles Bolden said at the National Cathedral service.

"But it was the courage, grace and humility he displayed throughout his life that lifted him above the stars."

Armstrong's Apollo 11 crew mates Michael Collins and Buzz Aldrin, Eugene Cernan -- the Apollo 17 mission commander and last man to walk on the moon -- attended the memorial service.

Also present Thursday was John Glenn, the former US senator and first American to orbit the Earth.

Armstrong came to be known around the world for the immortal words he uttered on July 20, 1969, as he became the first person ever to step onto another body in space: "That's one small step for (a) man, one giant leap for mankind."