The United States is to launch the third Space-Based Infrared System (SBIRS) satellite, SBIRS Geo 3, today on a United Launch Alliance (ULA) Atlas 5 rocket, designated AV-066, for missile early-warning detection and tactical support. The SBIRS sensors are designed to provide greater flexibility and sensitivity than Defense Support Program (DSP) satellites, which are planned to be replaced by SBIRS-High program satellites. SBIRS can also detect short-wave and expanded mid-wave infrared signals, enhancing the staellites capabilities. The first two satellites were launched in May, 2011 and March, 2013 respectively. SBIRS Geo 3 was ordered in June 2009 and built by Lockheed Martin.