The Space-Based Infrared System (SBIRS) is a United States Space Force system intended to meet the United States' Department of Defense infrared space surveillance needs through the first two to three decades of the 21st century. The SBIRS program is designed to provide key capabilities in the areas of missile warning, missile defense, battlespace characterization and technical intelligence via satellites in geosynchronous Earth orbit (GEO), sensors hosted on satellites in highly elliptical orbit (HEO), and ground-based data processing and control. A total of twelve satellites carrying SBIRS or STSS payloads had been launched: SBIRS GEO-1 (USA-230, 2011), SBIRS GEO-2 (USA-241, 2013), SBIRS GEO-3 (USA-273, 2017), SBIRS GEO-4 (USA-282, 2018), SBIRS GEO-5 (USA-315, 2021), SBIRS GEO-6 (USA-336, 2022), SBIRS HEO-1 (USA-184, 2006), SBIRS HEO-2 (USA-200, 2008), SBIRS HEO-3 (USA-259, 2014), STSS-ATRR (USA-205, 2009), STSS Demo 1 (USA-208, 2009) and STSS Demo 2 (USA-209, 2009). The manufacturing contract for SBIRS GEO-5 and SBIRS GEO-6 was awarded in 2014. Funding for SBIRS GEO-7 and SBIRS GEO-8 was canceled in 2019. Background Based on its experiences with the launching of short-range theater missiles by Iraq during the 1991 Persian Gulf War, the U.S. Department of Defense (DoD) concluded that expanded theater missile warning capabilities were needed, and it began planning for an improved infrared satellite sensor capability that would support both long-range strategic and short-range theater ballistic missile warning and defense operations. In 1994, DoD studied consolidating various infrared space requirements, such as for ballistic missile warning and defense, technical intelligence, and battlespace characterization, and it selected SBIRS to replace and enhance the capabilities provided by the Defense Support Program (DSP). DSP satellites are built with infrared detectors that can sense missile plumes, and have been providing early warning for long-range ballistic missile launches for over 30 years. DoD had previously attempted to replace DSP with: the Advanced Warning System in the early 1980s the Boost Surveillance and Tracking System in the late 1980s the Follow-on Early Warning System in the early 1990s According to the Government Accountability Office (GAO), these attempts failed due to immature technology, high cost, and affordability issues. SBIRS is to use more sophisticated infrared technologies than the DSP to enhance the detection of strategic and theater ballistic missile launches and the performance of the missile-tracking function. The original contract consisted of 2 SBIRS HEO satellite sensors and 2-3 SBIRS GEO sensors (and satellites) with an option to buy a