The Air Force is preparing for its January 19 launch of the Space-Based Infrared System (SBIRS) GEO-3 satellite. The satellite will be part of a constellation used to provide missile warning by identifying the infrared heat signatures of missiles during launch. This information is used to alert U.S. missile defense systems. The GEO-3 will be carried into orbit on board an Atlas V rocket. Next up for deployment is the SBIRS GEO-4, with a launch expected later this year.