Heart-stopping photos of the first untethered spacewalk mark 40th anniversary of daring feat

Heart-stopping photos of the first untethered spacewalk mark the 40th anniversary of the daring feat.

Bruce McCandless II was the first man to take an nerve-wracking romp through space without any tether to a spacecraft on Feb. 7, 1984.

The daring astronaut used the Manned Maneuvering Unit (MMU) to control his movements rather than being connected to the Challenger shuttle.

The photo of McCandless floating in space 320 feet from the shuttle has become one of NASA’s most popular archival pieces.

The mission had two untethered spacewalks, which proved to be the “most critical” for NASA, according to a press release.

During McCandless and Robert Stewart’s spacewalk, which happened on days four and five of the eight-day mission, the crew decreased the shuttle’s cabin pressure from 14.7 psi to 10.2 to reduce the time the two spacewalkers needed to pre-breathe pure oxygen and rid their blood of excess nitrogen. Too much nitrogen could result “in the bends when working in their spacesuits at 4.3 psi,” according to NASA.

The next day, McCandless and Stewart would take another spacewalk.

“That may have been one small step for Neil, but it’s a heck of a big leap for me,” McCandless joked.

McCandless then floated 150 feet away from the shuttle before returning and then going out 320 feet and then returning safely again. Stewart followed the same procedures.

“The two astronauts ended the spacewalk after 5 hours 55 minutes,” NASA said.

The mission also saw McCandless being “flown” above the spaceship, using the first “cherry picker” in space, a combined configuration of a Mobile Foot Restraint (MFR) and Remote Manipulator System (RMS).

Despite the extraordinary accomplishment, scientists were worried about the MMU.

“Many in the agency were fearful about the use of a self-propelled and untethered backpack in space,” Jennifer Ross-Nazzal, NASA Human Spaceflight Historian, said.

“Previous spacewalkers remained connected to the vehicle with tethers. This jet-pack allowed crews to move outside of the cargo bay and perform activities away from the safety of the spacecraft.”

It was McCandless’ first mission into space, although he had served as an astronaut since his selection in 1966, according to the space company.

He helped develop the MMU. He also helped create the Astronaut Maneuvering Unit, which is the MMU’s predecessor, inside the Skylab.

With Post wires