It is probably one of the most well-known picture from the history of spaceflight. This picture express the whole spirit of space expoloration with the free flying astronaut and the Earth with the blue oceans on the background. But you likely don’t know when, where and how that picture is made. This week’s “A picture from space” article is going to answer to these questions.

The picture is made on February 4, 1984 during the Space Shuttle Challenger’s STS-41-B mission. The STS-41-B mission lifted off from the Kennedy Space Center 8 am EST on February 3, 1984. The mission’s crew was Vance D. Brand, Robert L. Gibson, Bruce McCandless, Robert L. Stewart and Ronald E. McNair. The mission’s primary objective was the deployment of two communications satellite. The astronaut in the picture is Bruce McCandless who was tested the “Manned Manuvering Unit” (MMU). It was the first untethered spacewalk of the history of spaceflight. The astronauts usually tethered to the spacecraft to prevent the drift of the astronauts. The MMU gave the opportunity to free fly with the “armchair with rockets.” The MMU is a frame with a propulsion unit, attached to the astronauts. It also contained the spacewalker’s life support systems. It has a weight of 126 kilograms and was capacble of 25 m/s delta-v. NASA used the MMU for 3 missions before it was retired because it was judged too risky to use. Today the MMU has a successor, the “Simplified Aid For EVA Rescue” (SAFER) which is a smaller sized astronaut propulsion unit, and just used in the case of emergency. But nowdays the astronauts working tethered during EVAs and free flying is not allowed anymore.

(Picture: nasa.gov)