"40th Anniversary: NASA's Historic Untethered Spacewalk"

40 years ago, astronaut Bruce McCandless II made history by performing the first untethered spacewalk from the Space Shuttle Challenger using the Manned Maneuvering Unit (MMU). This iconic moment occurred during the STS-41B mission and marked a significant milestone in space exploration. The MMU allowed astronauts to maneuver untethered in space, but after the Challenger disaster, it was deemed too risky and eventually retired. McCandless, a key figure in the development of the MMU, passed away in 2017, leaving behind a legacy of pioneering space exploration.