Apollo 8 8 are the names of the three astronauts. The initial design of the insignia was developed by Jim Lovell, who reportedly sketched it while riding in the back seat of a T-38 flight from California to Houston shortly after learning of the Apollo 8's re-designation as a lunar-orbital mission. The crew wanted to name their spacecraft, but NASA did not allow it. The crew would have likely chosen "Columbiad", the name of the giant cannon that launches a space vehicle in Jules Verne's 1865 novel "From the Earth to the Moon". The Apollo 11 CM was named "Columbia" in part
Apollo 13 the Command Module Pilot. Seven days before launch, the backup lunar module pilot, Charlie Duke, contracted rubella from one of his children. This exposed both the prime and backup crews, who trained together. Mattingly was found to be the only one of the other five who had not had rubella as a child and thus was not immune. Three days before launch, at the insistence of the Flight Surgeon, Swigert was moved to the prime crew. Mattingly never contracted rubella and was assigned after the mission as command module pilot to Young's crew, which later flew Apollo 16, the fifth