WASHINGTON — The Air Force’s newest Space Based Infrared System missile-warning satellite is operational and has transmitted its first images, Lockheed Martin said March 21.

The SBIRS GEO Flight 3 spacecraft transmitted its first images back to Earth March 17, a milestone known as “first light.” The images themselves are classified due to the sensitive nature of the missile-warning mission.

The satellite launched Jan. 20 after a several month delay to investigate a potential engine issue, though no problem was found. The transmitted images confirm the SBIRS satellite reached geosynchronous orbit and is operational.

“With the satellite successfully on orbit, we are now working to ensure GEO Flight 3 continues the outstanding performance trends demonstrated by its predecessors, including better-than-specified sensor pointing accuracy and the ability to detect dimmer targets than expected,” David Sheridan, vice president of Lockheed Martin’s Overhead Persistent Infrared systems, said in a statement.

SBIRS is the Air Force’s primary missile-warning system, designed to detect launches as well as track missile flight paths and predict impact points. Although missile-warning systems were originally designed in the Cold War to detect nuclear ballistic missile launches from the Soviet Union, the Air Force and Lockheed Martin have been working to increase their sensitivity to detect lower-light ignitions from in-theater conventional missiles.

SBIRS GEO 3 is the first satellite to begin life operating with the Block 10 ground system upgrade. The new ground system — accepted operationally by the Air Force in December — collects and unifies missile-warning data and command and control from satellites in geosynchronous orbit, elliptical orbits, and the older Defense Support Program constellation.

The fourth satellite in the constellation is undergoing final assembly and testing at Lockheed Martin’s facility in Sunnyvale, California, in preparation for a scheduled Nov. 9 launch.

Lockheed is also constructing SBIRS 5 and 6, planned for 2021 and 2022 launches, respectively.