True story behind one of ‘most terrifying images ever’ taken by NASA

The remarkable true story behind one of the most terrifying photos in NASA's history has been revealed.

While the prospect of going into space might have blown the minds of nearly anyone 100 years ago, it's become almost commonplace these days, with Katy Perry somehow finding herself up there earlier this year.

If Jeff Bezos' plans for a space hotel come into fruition, then we may soon all have a chance to see the Earth from above, with the possibilities almost endless as technology continues to evolve.

But there's no doubting that space can be a pretty scary place. Famously, nobody can hear you scream there, while there's also the constant worry that aliens are watching our every move, so the last thing you'd want to do if you found yourself up there is distance yourself from the safety of the ship.

Back in 1984, Dale Gardner and Joseph Allen did just that, and it wasn't just a routine space walk, but a completely untethered one.

Astronaut Dale Gardner wasn't fazed that day (Fox Photos/Hulton Archive/Getty Images)

The crew - which consisted of commander Frederick H. 'Rick' Hauck, pilot David M. Walker, and mission specialists Joseph P. Allen, Anna L. Fisher, and Dale A. Gardner - worked as a team and took the brave (and perhaps reckless) decision to recover two communication satellites, named Westar 6 and Palapa B2, which had been placed into incorrect orbits due to rocket failure.

Gardner used a Manned Manoeuvring Unit (MMU), which is essentially a fancy way of saying a jetpack, to retrieve the Westar 6 satellite.

NASA later explained: "After Hauck and Walker piloted Discovery to within 35 feet of Palapa, Allen and Gardner exited the airlock to begin the spacewalk portion of the satellite capture.

"Allen donned the MMU mounted on the side wall of the cargo bay, attached the stinger to its arms, and flew out to Palapa. Once there, he inserted the stinger into the satellite’s Apogee Kick Motor bell and using the MMU’s attitude control system, stopped Palapa’s spins.

In 1984, the crew worked as a team to recover two communication satellites in space (NASA)

"Fisher then steered the RMS to capture a grapple fixture mounted on the stinger between Allen and the satellite. She then manoeuvred them over the payload bay where Gardner waited to remove its omnidirectional antenna and install the bridge structure.

"However, Gardner could not attach the ABS to the satellite due to an unexpected clearance issue on the satellite.

"Using a backup plan, Allen undocked from the stinger, leaving it attached to the satellite as well as the RMS, and stowed the MMU in the payload bay.

"With Allen now holding the satellite by its antenna, Gardner attached an adaptor to the bottom end of the satellite to secure it in its cradle in the payload bay."

Joseph Allen and Dale Gardner managed to pull off an incredibly risky maneuver in space (NASA)

With Westar secured in the payload bay, Gardner and Allen completed the second spacewalk in five hours and 42 minutes.

After completing their mission and travelling over 3 million miles in just seven days, the astronauts returned home.

Gardner sadly passed away in 2014, but he remains the only human in history to complete an untethered spacewalk for returning malfunctioning satellites from orbit.