An unmanned rocket blasted off from Vandenburg AFB along the California coast on April 3 carrying a clandestine new generation spy satellite for the U.S. military. Unlike many of the South Base launch pads, Vandenburg's SLC-6 launch pad is tucked into a valley and not visible for spectators, at least in the liftoff phase.
The United Launch Alliance (Boeing and Lockheed-Martin) Delta 4 rocket launched from Vandenberg Air Force Base at 4:12 p.m. PDT (2312 GMT) on a mission to orbit a highly classified satellite, called NROL-25, for the U.S. National Reconnaissance Office. This was an important launch for the Delta 4 program since it was the first to launch using a version of the booster called the "Delta 4 Medium-plus 5,2 configuration, which uses a common Delta 4 core flanked by twin solid rocket boosters and topped with a 5-meter fairing to cover the satellite payload." There are 3 other NRO satellite launches scheduled for this year, all thought to be next-generation radar imaging satellites, replacing several older, less advanced, and heavier radar recon satellites that the NRO had been utilizing.
Nice to see that the updates to the Delta 4 seems to have worked perfectly!