The S-IVB also ongoing to thrust in a low stage by venting gaseous hydrogen, to help keep propellants settled in their tanks and prevent gaseous cavities from forming in propellant feed lines. This venting also maintained Protected pressures as liquid hydrogen boiled off within the gas tank. This venting https://system-on-a-chip64196.daneblogger.com/30963169/apollo4-blue-plus-can-be-fun-for-anyone