Essex-class aircraft carrier and "Princeton" recovered the second crew to orbit the Moon, aboard Apollo 10, in May 1969. "Hornet" rejoined the program and recovered the astronauts from the first two moon landing missions, Apollo 11 in July 1969 and Apollo 12 in November. The first steps on Earth of returning astronauts Neil Armstrong, Buzz Aldrin, and Mike Collins, are marked on her hangar deck, as part of her Apollo program exhibit. The three subsequent missions utilized amphibious assault ships as support vessels; however, "Ticonderoga" recovered the astronauts of the last two moon missions, Apollo 16 and Apollo 17 in April and December
Apollo 8 CMP, and Buzz Aldrin as LMP for the third crewed Apollo flight was officially announced at the same time as the prime crew. When Lovell was reassigned to the prime crew, Aldrin was moved to CMP, and Fred Haise was brought in as backup LMP. Armstrong would later command Apollo 11, with Aldrin as LMP and Collins as CMP. Haise served on the backup crew of Apollo 11 as LMP and flew on Apollo 13 as LMP. During Projects Mercury and Gemini, each mission had a prime and a backup crew. For Apollo, a third crew of astronauts was added,