WASHINGTON — An Atlas 5 rocket lifted off Sept. 16 from Cape Canaveral Air Force Station, Florida, carrying a satellite for an unspecified U.S. government agency.

The launch of the satellite, known as CLIO, occurred at 8:10 p.m. EDT.

United Launch Alliance conducted the launch on behalf of Lockheed Martin Space Systems, which built the satellite.

Because the mission is classified, very few details about the launch or the payload’s purpose were publicly released. In an Aug. 21 press release, Lockheed Martin said only that the satellite was based on commercial technology and used the company’s A2100 satellite bus.

ULA reported a successful launch in a press release a few hours after liftoff.

“It is an honor to work with Lockheed Martin Space Systems Company and all of our mission partners to launch this very important satellite,” Jim Sponnick, ULA vice president for the Atlas and Delta programs, said.

The mission was ULA’s 11th launch this year.

Mike Gruss covers military space issues, including the U.S. Air Force and Missile Defense Agency, for SpaceNews. He is a graduate of Miami University in Oxford, Ohio.