A cryogenic propellant tank system and process for densifying cryogenic liquid propellant comprises a tank with a combined manifold, a combined manifold line, a pressurizing gas line, and a vent line. The combined manifold is located in the tank. The combined manifold line functionally connects the combined manifold to a chilling system. The pressurizing gas line and the vent line are also functionally connected to the combined manifold line. The tank may be disposed in a vehicle. The manifold is disposed proximate the top of the tank. The chilling system may be a heat exchanger/filling system. The process for filling the tank comprises the steps of charging the tank with cryogenic liquid propellant, venting gases in the tank, densifying the cryogenic liquid propellant, and pressurizing the tank. The tank is charged with the cryogenic liquid propellant such that the orifices in the combined manifold are submerged. The gases in the tank are vented through the combined manifold and out of the tank. The venting step is arrested prior to the submerging of the combined manifold orifices. The liquid in the tank is densified by directing a recirculation stream of the cryogenic liquid propellant from the tank through the combined manifold, out of the tank, cooling and directing the recirculation stream back into the tank. The tank is pressurized by directing a pressurizing gas stream into the combined manifold and into the tank.