A United Launch Alliance (ULA) Delta 4 rocket carrying a payload for the National Reconnaissance Office (NRO) lifted off from Vandenberg Air Force Base in California on Jan. 12. Because the mission — designated NROL 47 — is classified, NRO has not released information on what the satellite will be used for, stating only that the mission is in support of national defense.

ULA launched the mission aboard a Delta 4 Medium+ (5, 2) configuration Evolved Expendable Launch Vehicle (EELV) powered by one common booster core (powered by an RS-68A liquid hydrogen/liquid oxygen engine) and two solid rocket motors built by Orbital ATK. A single RL10B-2 liquid hydrogen/liquid oxygen engine powered the second stage. Aerojet Rocketdyne manufactured both the booster and upper stage engines.

ULA’s next launch is the Space Based Infrared System (SBIRS) GEO Flight 4 mission for the U.S. Air Force on an Atlas 5 rocket. The launch is scheduled for Jan. 18 from Space Launch Complex 41 at Cape Canaveral Air Force Station in Florida.