OrbitalHub

Wikipedia dixit:

“The Space-Based Infrared System (SBIRS) is a consolidated system intended to meet the United States’ 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 and battlespace characterization.

SBIRS is an integrated “system of systems” that will include satellites in geosynchronous orbit (GEO), sensors hosted on satellites in highly elliptical orbit (HEO), and ground-based data processing and control. A complement of satellites in low earth orbit was planned as part of the program (SBIRS Low), but this has been moved into the STSS program. SBIRS ground software integrates infrared sensor programs of the U.S. Air Force (USAF) with new IR sensors. SBIRS continues to struggle with cost overruns, with Nunn-McCurdy breaches occurring in 2001 and 2005. By September 2007, the expected project cost had increased to $10.4 billion. The original contract consisted of 2 HEO satellite sensors and 2-3 GEO sensors (and satellites) with an option to buy a total of 5 GEOs. In December 2005, following the third SBIRS Nunn-McCurdy violation, the government decided to compete GEO 4 and 5, with an option to buy the GEO 3 contingent based on the performance of the first two. Additionally, the government started a potential SBIRS High replacement program, writing out proposals in June 2006.

On June 2, 2009 Lockheed Martin announced it had been awarded a contract for the third HEO payload and the third GEO satellite, and for associated ground equipment modifications. On July 10, 2009, Lockheed Martin was awarded $262.5 million as down payment by the USAF towards the purchase of a fourth satellite. The first GEO satellite of the SBIRS program, GEO-1, was successfully launched from Cape Canaveral on an Atlas V rocket on May 7, 2011.

In summary, as of January 2017, a total of nine satellites carrying SBIRS or STSS payloads had been launched: GEO-1 (USA-230, 2011), GEO-2 (USA-241, 2013), GEO-3 (USA-273, 2017), HEO-1 (USA-184, 2006), HEO-2 (USA-200, 2008), HEO-3 (USA-259, 2014), STSS-ATRR (USA-205, 2009), STSS Demo 1 (USA-208, 2009) and STSS Demo 2 (USA-209, 2009). In June 2014, Lockheed Martin was contracted by the USAF to build GEO-5 and GEO-6, at a cost of $1.86 billion.”

Video credit: ULA