About the time of the first landing in 1969, it was decided to use an existing Saturn V to launch the Skylab orbital laboratory pre-built on the ground, replacing the original plan to construct it in orbit from several Saturn IB launches; this eliminated Apollo 20. NASA's yearly budget also began to shrink in light of the successful landing, and NASA also had to make funds available for the development of the upcoming Space Shuttle. By 1971, the decision was made to also cancel missions 18 and 19. The two unused Saturn Vs became museum exhibits at the John F. Kennedy Space Center on Merritt Island, Florida, George C. Marshall Space Center in Huntsville, Alabama, Michoud Assembly Facility in New Orleans, Louisiana, and Lyndon B. Johnson Space Center in Houston, Texas.
What Apollo mission was first cancelled due to not being needed to build the Skylab in space, as it was pre-built on the ground? What happened to NASA's budget after the first successful moon landing? After Apollo missions 18 and 19 were cancelled, what happened to the Saturn Vs that were never used? What year was the decision made to cancel Apollo missions 18 and 19?