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
Moon landing of water for 24 hours on the ground, to protect the Moon from being contaminated by Earth organisms. Heat sterilization was also blamed for subsequent in-flight failures of the spacecraft computer on Ranger 4 and the power subsystem on Ranger 5. Only Ranger 4 reached the Moon in an uncontrolled crash impact on the far side of the Moon. Heat sterilization was discontinued for the final four Block III Ranger probes. These replaced the Block II landing capsule and its retrorocket with a heavier, more capable television system to support landing site selection for upcoming Apollo manned Moon landing missions.