Neil Armstrong December 23, 1968, as Apollo 8 orbited the Moon. In a meeting that was not made public until the publication of Armstrong's biography in 2005, Slayton told him that although the planned crew was Commander Armstrong, Lunar Module Pilot Buzz Aldrin, and Command Module Pilot Michael Collins, he was offering Armstrong the chance to replace Aldrin with Jim Lovell. After thinking it over for a day, Armstrong told Slayton he would stick with Aldrin, as he had no difficulty working with him and thought Lovell deserved his own command. Replacing Aldrin with Lovell would have made Lovell the lunar module
Hervé Stevenin Environment Mission Operations (NEEMO 16). In September 2013, Stevenin and ESA astronaut Jean-François Clervoy slipped into the roles of Neil Armstrong and Buzz Aldrin for an underwater simulation test of Apollo 11 moonwalk tasks, organised by the Compagnie maritime d'expertises (COMEX) off the coast of Marseilles, France. They tested a COMEX-designed prototype training-spacesuit based on the Orlan adapted to simulate Moon gravity. Stevenin became an aquanaut through his participation in the NASA NEEMO 19 mission simulating undersea a space exploration mission aboard Aquarius, the world only undersea research laboratory with crewmates NASA astronaut Randy Bresnik, ESA astronaut Andreas Mogensen and