(CNN) -- Neil Armstrong, the first man to walk on the moon, was honored Thursday at Washington National Cathedral in a memorial rife with mentions of heaven and earth.
On Friday, his cremated remains were buried at sea with his wife and family members in attendance aboard the USS Philippine Sea in the Atlantic Ocean.
Hundreds of mourners, including Armstrong's family and fellow astronauts, packed the massive house of worship for a public "celebration of (Armstrong's) life," three weeks after he died on August 25 at age 82.
The cathedral's interim dean, the Rev. Dr. Francis H. Wade, called the ceremony an opportunity to "give thanks for a life well-lived and service nobly rendered."
Armstrong earned his renown commanding the Apollo 11 space mission and landing on the moon on July 20, 1969, when he was 38.
"Neil will always be remembered for taking humankind's first small step on a world beyond our own. But it was courage, grace, and humility he displayed throughout his life that lifted him above the stars," NASA Administrator Charles Bolden said at the service, about an hour before he presented Armstrong's family with the American flag that flew over Johnson Space Center on the day the space pioneer died.
Bolden didn't speak just on behalf of himself and NASA. The space agency chief also relayed portions of a letter President Obama wrote to the Armstrong family, which read, in part, "Future generations will draw inspiration from his spirit of discovery, humble composure, and pioneering leadership, in setting a bold new course for space exploration. The imprint he left on the surface of the moon, and the story of human history, is matched only by the extraordinary mark he left on the hearts of all Americans."
Alternating between musical and prayer interludes, luminary after luminary described Armstrong as an extraordinary man who had performed extraordinary deeds, yet retained his humility and tried to diffuse the credit and fame he received among thousands of other NASA engineers, scientists, technicians and fellow astronauts.
Retired Navy Capt. Eugene Cernan was the last man to walk on the moon, in December 1972, when he commanded the Apollo 17 mission. He paid homage to the founding member of his exclusive fraternity.
"He understood the immensity of what he had done. Yet Neil was always willing to give of himself," Cernan said, later adding, "No one could have accepted the responsibility of his remarkable accomplishment with more dignity and more grace than Neil Armstrong. He embodied all that is good and all that is great about America."
Treasury Secretary John Snow, a friend of Armstrong's, called him "the most reluctant of heroes."
"With his uncommon humility and grace, Neil captured the very best of the American character and put it on display for the world to see," he said.
CNN's John Zarrella contributed to this report.
™ & © 2012 Cable News Network, Inc., a Time Warner Company. All rights reserved.