ATLAS II-CENTAUR FACT SHEET
By Cliff Lethbridge
Atlas II-Centaur On Launch Pad, Photo Courtesy Lockheed-Martin
Classification: Space Launch Vehicle
Length: 149 feet, 7 inches (with medium fairing)
Length: 155 feet, 10 inches (with large fairing)
Diameter: 10 feet
Date of First Cape Canaveral Launch: December 7, 1991
Date of Final Cape Canaveral Launch: July 25, 1996
Number of Cape Canaveral Launches: 9
The Atlas II-Centaur was developed in 1989 specifically to support the launches of U.S. Air Force Defense Support Communications Satellite (DSCS) payloads. The vehicle employed two Rocketdyne booster engines which provided a combined thrust of 408,000 pounds. One Rocketdyne sustainer engine provided an additional 60,500 pounds of thrust at liftoff. All of the lower stage engines burned liquid oxygen/RP-1 (kerosene) liquid fuel. In a departure from all previous Atlas applications, the Atlas II-Centaur did not carry vernier engines. Rather, the interstage which connected the Centaur second stage with the rocket’s lower stages housed two hydrazine-fueled modules. Each module contained two thruster units which could produce 100 pounds of thrust each. These interstage thrusters performed the roll and velocity trim stabilization functions previously handled by vernier engines.
An Integrated Apogee Boost Subsystem was employed specifically as an additional upper stage for DSCS satellite operations. This stage operated with twin Marquardt engines producing 110 pounds of thrust each. The overall Integrated Apogee Boost Subsystem was 27 feet long and 9 feet, 6 inches wide and burned MMH and MON3 propellant. This booster was spin-stabilized at 30 revolutions per minute and was controlled by the satellite payload itself. With the medium fairing, the Atlas II-Centaur could carry a 14,950-pound payload to low-Earth orbit, a 6,100-pound payload to geosynchronous transfer orbit or a 4,270-pound payload to Earth-escape trajectory. With the large fairing, the Atlas II-Centaur could carry a 14,500-pound payload to low-Earth orbit, a 5,900-pound payload to geosynchronous transfer orbit or a 4,020-pound payload to Earth-escape trajectory.