NASA astronaut Bruce McCandless, the first person to fly freely and untethered in space, has died. He was 80.

He was famously photographed in 1984 flying with a hefty spacewalker's jetpack, alone in the cosmic blackness above a blue Earth. He traveled more than 300 feet away from the space shuttle Challenger during the spacewalk.

"The iconic photo of Bruce soaring effortlessly in space has inspired generations of Americans to believe that there is no limit to the human potential," Sen. John McCain said in a statement. The Arizona Republican and McCandless were classmates at the U.S. Naval Academy.

NASA's Johnson Space Center said Friday that McCandless died Thursday in California. No cause of death was given.

McCandless said he wasn't nervous about the historic spacewalk."I was grossly over-trained. I was just anxious to get out there and fly. I felt very comfortable ... It got so cold my teeth were chattering and I was shivering, but that was a very minor thing," he told the Daily Camera in Boulder, Colorado, in 2006.