Space Stats

The Titan 4B launch vehicle evolved from Titan 3 family and was similar to the Titan 34D. Consists of two upgraded solid rocket motors (known as SRMUs); a two-stage liquid-propellant core; a liquid-fuel upper stage; and a payload fairing.

The three-segment SRMUs are 3.2 meters (10.5 feet) in diameter and 34.2 meters (112.4 feet) long. Each motor contains 312,458 kilograms (688,853 pounds) of hydroxyl terminated polybutadiene (HTPB) propellant and provides a maximum thrust of 7.56 million newtons (1.7 million pounds) at sea level. Flight control is achieved by directing the thrust through a gimbaled nozzle controlled by hydraulic actuators. Six staging rockets on each SRMU ensure positive separation from the core following SRMU burnout.

The first stage of the 3.04-meter-diameter (10-foot) core is powered by a twin assembly LR87-AJ-11 engine, while the second stage is powered by a single assembly LR91-AJ-11 engine. Both stages use storable hypergolic propellants (propellants that ignite when they come in contact with each other). The fuel is aerozine 50, a 50-50 mixture of hydrazine and unsymmetrical dimethyl hydrazine. During combustion, the fuel is mixed with nitrogen tetroxide as an oxidizer.

Vehicle flight control and navigation for the Titan are provided by the guidance control unit, which includes a flight control subsystem and an inertial measurement subsystem. The first stage separates from the second stage when the second-stage engine ignites. Separation of the second stage and the upper stage is achieved when four retrorockets fire and a structural adapter is severed by pyrotechnics called "SuperZip."