United Launch Alliance have successfully performed a rocket launch of an Atlas V rocket placing the SBIRS GEO-4 satellite for the US Air Force into geosynchronous orbit. Liftoff occurred at 00:48 UTC, January 20th 2018 from Space Launch Complex 41 at Cape Canaveral on an Atlas V in the 411 configuration.
Space Based Infrared Systems (SBIRS) is a system of satellites designed to detect missle launches as part of an advance warning system for the United States.
