The powerful United Launch Alliance Delta 4 Heavy, one of the four remaining on the company’s books, exploded from California on Monday afternoon, lifting a classified National Reconnaissance Agency spy satellite into space.
Aerojet Rocketdyne RS-68A engine powers three side-by-side “common booster cores” of the rocket, thundering at 4:47 pm with a roaring flame and launching a 233-foot-high vehicle. Moved away from the facility 6. At Vandenberg Air Force Base, northwest of Los Angeles.
A hydrogen-fueled engine that produces 2.1 million pounds of thrust (equivalent to 51 million horsepower) quickly propells a rocket into the sky, arcing along a path south of the Pacific Ocean at 5,000 pounds per second. Consumed liquid hydrogen and oxygen propellants.
Two outboard common core boosters were dumped approximately four minutes after takeoff after helping lift the rocket from the dense lower atmosphere. The central booster also continued to fire an additional 1 minute and 40 seconds ago and was abandoned.
The flight continued on the power of the rocket’s single RL10B-2 second stage engine, but as usual in the classified NRO missions, the United Launch Alliance finished the mission description after a few minutes and the rest of the flight It was done in secret.
Launch timing and rocket orbit are tilted approximately 98 degrees with respect to the equator based on safety notices posted prior to takeoff, and previously classified optical imaging capable of collecting a very detailed view of ground targets. It was exactly the same as the path to the orbit used by the satellite.
However, the National Reconnaissance Office does not provide information about the classified payload or its trajectory and does not comment on external speculation.
The United Launch Alliance is a partnership between Lockheed Martin, the builder of the Atlas 5 rocket family, and Boeing, who designed the Delta 4. The launch on Monday was the thirteenth of the most powerful Delta 4 Heavy variants.
ULA will phase out Delta 4, eventually Atlas 5, and adopt a new Balkan rocket that can be used in multiple configurations with a reusable Stage 1 engine.