CAPE CANAVERAL AIR FORCE STATION, Fla. - The first Lockheed Martin-built Space Based Infrared System geosynchronous spacecraft was encapsulated into its payload fairing April 20 in preparation for an early May liftoff aboard an Atlas V rocket. SBIRS GEO-1 will enhance the nation's missile warning capabilities and improve other critical mission areas. The GEO-1 satellite includes sophisticated scanning and staring sensors that will deliver enhanced infrared sensitivity and a reduction in area revisit times over the current constellation. (Source: Lockheed Martin, 04/26/11) SBIRS is an A2100 satellite-based spacecraft. Work on the A2100 core's propulsion system, which positions the spacecraft in orbit, is done at Stennis Space Center, Miss. (Source: Alliance Insight, pp 4-5, July 2009)