Editing Apollo 14 (section)

=== Launch vehicle ===
The [[Saturn V]] used for Apollo 14 was designated SA-509, and was similar to those used on [[Apollo 8]] through 13.{{sfn|Press Kit|p=90}} At {{convert|6505548|lb}}, it was the heaviest vehicle yet flown by NASA, {{convert|3814|lb}} heavier than the launch vehicle for Apollo 13.<ref name = "journal launch">{{cite web|work=Apollo Lunar Flight Journal|url=https://history.nasa.gov/afj/ap14fj/01_day01_launch.html|title=Day 1: The launch|date=June 5, 2020|access-date=July 21, 2020|archive-date=October 27, 2020|archive-url=https://web.archive.org/web/20201027155543/https://history.nasa.gov/afj/ap14fj/01_day01_launch.html|url-status=dead}}</ref>

A number of changes were made to avoid [[pogo oscillation]]s, that had caused an early shutdown of the center [[Rocketdyne J-2|J-2]] engine on Apollo 13's [[S-II]] second stage. These included a helium gas accumulator installed in the liquid oxygen (LOX) line of the center engine, a backup [[Blanking and piercing|cutoff]] device for that engine, and a simplified 2-position propellant utilization valve on each of the five J-2 engines.{{sfn|Press Kit|p=93}}