The 'scariest photo ever taken in space' has an incredible story behind it, as it captured an astronaut completely cut off from everything else.

The solution was bold: a self-contained propulsion unit strapped to an astronaut’s back. Known as the Manned Maneuvering Unit (MMU), this device would allow astronauts to move freely in space ...

McCandless’s venture was made possible by the Manned Maneuvering Unit (MMU), a groundbreaking propulsion device he helped develop. This nitrogen-powered jetpack allowed for precise ...