Centaur D-1T propulsion and propellant systems

Modifications are described which have been introduced to the Centaur high-energy upper stage (which is being integrated with the Titan IIIC booster) to improve mission flexibility and reliability, and to provide three-burn synchronous orbit capability. The addition of a sidewall radiation shield significantly reduces heat transfer to the liquid hydrogen tank. This radiation field, in conjunction with a newly developed computer controlled propellant tank venting and pressurization system, permits the use of improved techniques for propellant management during orbital coast. Some minor changes in the propulsion and propellant systems which were necessary to adapt these systems for synchronous orbit trajectories are described, together with the redundancy incorporated to reduce the number of single failure points.-