First Untethered, Free Flight, Bruce McCandless II, Naval Aviator

McCandless logged over 312 hours in space, including four hours of MMU flight time. He flew as a mission specialist on STS-41-B and STS-31.
STS-41-B: Challenger launched from Kennedy Space Center, Florida, on February 3, 1984. The flight deployed two communications satellites, and flight-tested rendezvous sensors and computer programs for the first time.
This mission marked the first checkout of the Manned Maneuvering Unit (MMU) and Manipulator Foot Restraint (MFR). McCandless made the first, untethered, free flight on each of the two MMUs carried on board.