Mission Specialist Bruce McCandless II, is seen further away from the confines and safety of his ship than any previous astronaut has ever been. This space first was made possible by the Manned Manuevering Unit or MMU, a nitrogen jet propelled backpack. After a series of test maneuvers inside and above Challenger's payload bay, McCandless went "free-flying" to a distance of 320 feet away from the Orbiter. This stunning orbital panorama view shows McCandless out there amongst the black and blue of Earth and space. STS-41-B was the tenth NASA Space Shuttle mission and the fourth flight of the Space Shuttle Challenger. It launched on February 3, 1984, and landed on February 11 after deploying two communications satellites. It was also notable for including the first untethered spacewalk.