The Atlas I is a derivative of the Atlas/Centaur built by General Dynamics Space Systems Division (GDSSD) for NASA. The Atlas/Centaur previously was used by NASA as its standard launch vehicle for intermediate weight payloads. Atlas I is the first of a new family of launch vehicles that can be used to boost payloads into low-Earth orbit, geosynchronous-Earth orbit and on interplanetary trajectories. Eleven-foot and 14-foot diameter payload fairings are available to accommodate a variety of spacecraft.
The Centaur upper stage was the nation's first high-energy, liquid hydrogen/liquid oxygen propelled rocket. Developed and launched under the direction of NASA's Lewis Research Center, Cleveland, it became operational in 1966 with the launch of Surveyor 1, the first U.S. spacecraft to soft-land on the lunar surface.
Since that time, both the Atlas booster and the Centaur upper stage have undergone many improvements. At present, the Atlas I vehicle/14-foot fairing combination can place 13,000 pounds into low-Earth orbit, 4,950 pounds in a synchronous transfer orbit and 2,400 pounds on Earth escape trajectories. Since the first use of Atlas in the space program in the early 1960s, thrust of the Atlas engines has been increased about 50,000 pounds.
The Atlas I vehicle, approximately 143-feet high, consists of an Atlas I booster and a Centaur I upper stage. The Atlas booster develops 438,922 pounds of thrust at liftoff using two 188,750-pound-thrust booster engines, one 60,500-pound-thrust sustainer engine and two vernier engines developing 461 pounds of thrust each. The two RL-10 engines on Centaur produce a total of 33,000 pounds of thrust. Both the Atlas and Centaur are 10 feet in diameter.
Until early 1974, Centaur was used exclusively in combination with the Atlas booster. Subsequently, it was used with a Titan III booster to launch heavier payloads into Earth orbit and interplanetary trajectories. A new wide-body Centaur will be used as an upper stage on Titan IV launch vehicles.
The Centaur I has an integrated electronic system that performs a major role in checking itself and other vehicle systems before launch and also maintains control of major events after liftoff. The new Centaur system handles navigation and guidance tasks, controls, pressurization and venting, propellent management, telemetry forms and transmission and initiates vehicle events. Most operational needs can be met by changing the computer software.
[back to contents]The fueled AC-69 weight, including the 3,735-pound CRRES spacecraft, is 365,374 pounds. Liftoff height is approximately 143 feet. Launch Complex 36 (Pad B) is used for the launch operation.
ATLAS BOOSTER CENTAUR STAGE
Fueled Weight: 320,821 lbs. 40,818 lbs.
Height: Approx. 77 feet Approx. 67 feet
with payload fairing
Thrust: 438,922 lbs. 33,000 lbs.
at sea level in vacuum
Propellants: Liquid oxygen Liquid oxygen/
and RP-1 Liquid hydrogen
Propulsion: MA-5 system two Two 16,500 pound
188,750 lb. thrust thrust RL-10
booster engines, one engines, 12 small
60,500 lb. thrust hydrazine thrusters
sustainer engine, two
461 lb. thrust vernier
engines
Velocity: 6,527 mph at booster 22,262 mph
engine cutoff (BECO) at spacecraft
9,326 mph at sustainer separation
engine cutoff (SECO)
Guidance Preprogrammed profile Inertial guidance
through BECO. Switch
to inertial guidance
for sustainer phase
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