designed to help correct or ameliorate the discomfort of disorders of the spine and joints: orthopaedic mattresses Collins English Dictionary - Complete & Unabridged 2012 Digital Edition Â© William Collins Sons & Co. Ltd. 1979, 1986 Â© HarperCollins
Definition of Immelmann. : a maneuver in which an airplane reverses direction by executing half of a loop upwards followed by half of a roll âcalled also Immelmann turn.
U.S. astronaut Bruce McCandless uses a manned maneuvering unit. The Manned Maneuvering Unit (MMU) is an astronaut propulsion unit that was used by NASA on three Space Shuttle missions in 1984. The MMU allowed the astronauts to perform untethered EVA spacewalks at a distance from the shuttle. The MMU was used in practice to retrieve a pair of faulty communications satellites, Westar VI and Palapa B2.