In 1969, Apollo XI astronauts Neil Armstrong and Edwin "Buzz" Aldrin blasted off from the moon after 21 1/2 hours on the surface and returned to the command module piloted by Michael Collins. The Lunar module was comprised of two stages. The decent stage had the landing gear, and was used as a launch pad for the ascent stage. The ascent stage was mainly the cabin, and had a fixed thrust engine (15,500-Newton-thrust) to propel it to 2000 m/s in Lunar orbit for docking. The lunar module's lower section, left behind, has a plaque mounted upon it, reading, "Here men from the planet Earth first set foot upon the moon, July 1969 A.D. We came in peace for all mankind."