Apollo 11 insignia. At Scheer's suggestion, the CM was named "Columbia" after "Columbiad", the giant cannon that launched a spacecraft (also from Florida) in Jules Verne's 1865 novel "From the Earth to the Moon". It also referenced Columbia, a historical name of the United States. The astronaut had personal preference kits (PPKs), small bags containing personal items of significance that they wanted to take with them on the mission. Five PPKs were carried on Apollo 11: three (one for each astronaut) were stowed on "Columbia" before launch, and two on "Eagle". Neil Armstrong's LM PPK contained a piece of wood from the
Apollo 21 in orbit. Some people have speculated that tentative plans of an "Apollo 21" might have been made assuming availability of the extra Saturn V that would have left, although by the time NASA resumed planning manned missions using this numbering sequence (defined on April 24, 1967), the dual-Saturn IB plan had been replaced with the single Saturn V. There is no evidence NASA ever planned an eleventh Moon landing mission. Apollo 21 "Apollo 21" is an apocryphal reference to an eleventh manned Moon landing mission of NASA's Apollo program. Apollo contracted for the construction of fifteen Saturn V launch vehicles