WASHINGTON — United Launch Alliance launched a classified National Reconnaissance Office spy satellite on a Delta 4 Heavy rocket April 26 at 1:47 p.m. Pacific from Space Launch Complex-6 at Vandenberg Air Force Base, California.

The flight of NROL-82, a classified national security mission, marked ULA’s first launch of the year

The outer boosters of the three-core Delta 4 Heavy separated about four minutes into flight, followed by staging and ignition of the second stage two minutes later.

Per government request, ULA ended the webcast about seven minutes into the flight. The Office of the Director of National Intelligence confirmed on Twitter that the mission was successful.

The original liftoff time for NROL-82 of 1:46 p.m. Pacific was delayed by one minute due to a collision avoidance warning. That one-minute window was determined not safe to launch because the trajectory of the ascending rocket and payload would pass too close to another object in space.

NROL-82 is the first of four remaining Delta 4 Heavy missions that the Space Force contracted with ULA and are projected to be completed by 2024. ULA then plans to retire the Delta 4 Heavy and replace it with the new Vulcan Centaur rocket.

NROL-82 was ULA’s 143rd mission and the 13th for the triple-core Delta 4 Heavy powered by three Aerojet Rocketdyne RS-68A main engines. The Delta 4 Heavy’s cryogenic second stage is powered by the Aerojet Rocketdyne RL10B-2 engine.

ULA last launched a Delta 4 Heavy December 10. That mission, NROL-44, suffered setbacks, including two last-second aborts caused by issues with the ground equipment at the launch pad at Cape Canaveral, Florida. 

ULA CEO Tory Bruno told reporters in December that the company preemptively tested and refurbished the ground systems at Cape Canaveral and Vandenberg to ensure the final four missions of the Delta 4 Heavy do not encounter these problems again.

Sandra Erwin writes about military space programs, policy, technology and the industry that supports this sector. She has covered the military, the Pentagon, Congress and the defense industry for nearly two decades as editor of NDIA’s National Defense...