A spy satellite for the U.S. National Reconnaissance Office was launched from Vandenberg Air Force Base on Saturday night.

United Launch Alliance (ULA) launched an Atlas V rocket on Saturday evening, carrying out the classified NROL-42 mission for the United States National Reconnaissance Office. Atlas – delayed two days via the requirement to changeout a battery on the booster – lifted off from California’s Vandenberg Air Force Base at 22:49 Pacific Time (05:49 UTC on Sunday).

National Reconnaissance Office satellites gather intelligence information for U.S. national security and an array of other purposes including assessing impacts of natural disasters.

U.S. officials have not revealed what the spacecraft will be doing or what its orbit will be.

United Launch Alliance is a joint venture of Lockheed Martin and Boeing.