Bruce McCandless II performs the first untethered spacewalk on February 7, 1984 - Our Planet
NASA astronaut Bruce McCandless during the first untethered spacewalk in history. In this photograph taken on February 7, 1984 by his fellow crewmembers aboard the Earth-orbiting Space Shuttle Challenger on the STS-41B mission, McCandless II approaches his maximum distance (98 meters/320 feet) from the vehicle. McCandless became the first astronaut to maneuver about in space untethered, during this first "field" tryout of a nitrogen-propelled, hand-controlled backpack device called the Manned Maneuvering Unit (MMU). Not long afterward, NASA discontinued such actions and decided to perform only tethered spacewalks for safety reasons. In 1994, NASA unveiled a new backpack called Simplified Aid for EVA Rescue, or Safer, and tested it with an untethered spacewalk, the fourth, and thus far last untethered extra-vehicular activity it has performed. Every astronaut at the International Space Station wears Safer, which is smaller and lighter than the manned maneuvering units, for use during an emergency. You can see this image with max. resolution on NASA.gov