HOUSTON – Former NASA astronaut Bruce McCandless II died Thursday at the age of 80.

McCandless, a retired U. S. Navy captain, was one of the 19 astronauts selected by NASA in April 1966.

He was a mission specialist on the STS-41B and STS-31 missions. On STS-41B in 1984, he performed his famous spacewalk and, on STS-31 in 1990, he helped deploy the Hubble Space Telescope.

He known for being the first astronaut to fly untethered from his spacecraft. The photo of him flying alongside the space shuttle in the Manned Maneuvering Unit is one of NASA's most famous photographs.

He logged more than 312 hours in space, including four hours of flight time using the MMU.

Of his famous spacewalk, he wrote in 2015 "My wife Bernice was at mission control, and there was quite a bit of apprehension. I wanted to say something similar to Neil (Armstrong) when he landed on the moon, so I said, 'It may have been a small step for Neil, but it’s a heck of a big leap for me.' That loosened the tension a bit."

McCandless also served as the mission control communicator for Neil Armstrong's and Buzz Aldrin's moonwalk on the Apollo 1 mission.

"Our thoughts and prayers go out to Bruce's family," said Robert Lightfoot, NASA's acting administrator. "He will always be known for his iconic photo flying the MMU."

McCandless was the son of late U.S. Navy Rear Admiral Bruce McCandless and his wife. Admiral McCandless received the Congressional Medal of Honor for the naval battle of Guadalcanal, Dec. 12-13, 1942. He died in 1968. McCandless' paternal grandfather, U.S. Navy Commodore, and later Rear Admiral, Byron McCandless received the Navy Cross for World War I, and his maternal grandfather, U.S. Navy Capt. Willis Winter Bradley, was the first recipient of the Congressional Medal of Honor in World War I.

McCandless is survived by his wife, Ellen Shields McCandless, of Conifer, Colorado; his son, Bruce McCandless III, of Austin, Texas, and his wife, Patricia; his daughter, Tracy McCandless, of Islamorada, Florida; and two granddaughters, Emma Rose and Carson Clare McCandless, of Austin, Texas. He is also survived by a brother, Douglas M. McCandless, of Washington, D.C.; and two sisters, Sue M. Woodridge, of Texas, and Rosemary V. McCandless, of Dallas, Texas.

Here are some of the awards and honors received by McCandless:

Legion of Merit (1988)

Department of Defense Distinguished Service Medal (1985)

National Defense Service Medal

American Expeditionary Service Medal

NASA Exceptional Service Medal (1974)

American Astronautical Society Victor A. Prather Award (1975, 1985)

NASA Space Flight Medal (1984)

NASA Exceptional Engineering Achievement Medal (1985)

National Aeronautic Association Collier Trophy (1985)

Smithsonian Institution National Air and Space Museum Trophy (1985)

McCandless was responsible for crew inputs to the development of hardware and procedures for: