S69-31042 (18 April 1969) --- Suited astronaut Neil A. Armstrong, wearing an Extravehicular Mobility Unit (EMU), participates in lunar surface simulation training on April 18, 1969, in Building 9, Manned Spacecraft Center (MSC). Armstrong is the prime crew commander of the Apollo 11 lunar landing mission. Here, he is standing on Lunar Module (LM) mockup foot pad preparing to ascend steps.