Centaur (rocket Stage)

Centaur (rocket Stage)

Centaur is a rocket stage designed for use as the upper stage of space launch vehicles. Centaur boosts its satellite payload to geosynchronous orbit or, in the case of an interplanetary space probe, to or near to escape velocity. Centaur was the world's first high-energy upper stage, burning liquid hydrogen (LH2) and liquid oxygen (LOX).

Centaur, named after the centaurs of Greek mythology, was the brainchild of Karel J. "Charlie" Bossart (the man behind the Atlas ICBM) and Dr. Krafft A. Ehricke, both Convair employees. Their design was essentially a smaller version of the Atlas, with its concept of using lightweight "stainless steel balloon" tanks whose structural rigidity was provided solely by the pressure of the propellants within. To keep the tanks from collapsing prior to propellant loading, they were either kept in "stretch" or pressurized with nitrogen gas.

Centaur uses a common double-bulkhead to separate the LOX and LH2 tanks. The two stainless steel skins are separated by a 0.25 inch (6.4 mm) layer of fiberglass honeycomb. The extreme cold of the LH2 on one side creates a vacuum within the fiberglass layer, giving the bulkhead a low thermal conductivity, and thus preventing heat transfer from the relatively warm LOX to the super cold LH2. It is powered by one or two RL10 rocket engines (SEC and DEC variants respectively).