The Space-Based Infrared System (SBIRS) is a consolidated system intended to meet United States infrared space surveillance needs through the first two to three decades of the 21st century. SBIRS primary mission is to provide initial warning of a ballistic missile attack on the US, its deployed forces or its allies. SBIRS is an integrated "system of systems" that includes satellites in geosynchronous orbit (GEO) and low Earth orbit (LEO), sensors hosted on satellites in highly elliptical orbit (HEO) and ground data processing and control. SBIRS integrates previously independent infrared sensor programs of the U.S. Air Force and intelligence agencies. It incorporates new technologies that enhance detection and improve reporting of intercontinental ballistic missile, sea-launched ballistic missile and theater ballistic missile launches, and provide critical mid-course tracking and discrimination data for theater and national missile defense. SBIRS was experiencing cost overruns as of 2003 and is now expected to cost over $10 billion.

Contents

1 Background 2 SBIRS High 3 SBIRS Low 4 Source

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. The Defense Support Program is a strategic surveillance and early warning satellite system with an infrared capability to detect long-range ballistic missile launches that has been operational for about 30 years. DOD has previously attempted to replace the Defense Support Program 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
• the Alert, Locate, and Report Missiles (ALARM) System in the mid-1990s.

According to the GAO, these attempts failed due to immature technology, high cost, and affordability issues. SBIRS is to use more sophisticated infrared technologies than the Defense Support Program to enhance the detection of strategic and theater ballistic missile launches and the performance of the missile-tracking function

SBIRS High

SBIRS High is to consist of four satellites operating in geosynchronous earth orbit and sensors on two host satellites operating in a highly elliptical orbit. SBIRS High will replace Defense Support Program satellites and is primarily to provide enhanced strategic and theater ballistic missile warning capabilities. The SBIRS High program includes the consolidation of the three existing DSP ground facilities (two overseas and one in the US) at a single U.S. ground station to reduce costs. SBIRS High is in the engineering and manufacturing development phase, with a scheduled first launch in 2005.

SBIRS Low

The SBIRS Low program is expected to consist of about 24 satellites in low earth orbit. The primary purpose of SBIRS-low is tracking ballistic missiles and discriminating between the warheads and other objects, such as decoys, that separate from the missile bodies throughout the middle portion of their flights. It has two major sensors which it must coordinate with an on-board computer:

• a scanning infrared sensor, which is to acquire ballistic missiles in the early stages of flight.
• a tracking infrared sensor, which is to follow missiles, warheads, and other objects such as debris and decoys during the middle and later stages of flight. The tracking sensor will be cooled to very low temperatures.

SBIRS Low's original deployment schedule was 2010, the date when its capabilities are needed by the National Missile Defense System. The first SBIRS Low satellites need to be launched in 2006 if full deployment is to be accomplished by 2010.

Source

Space-Based Infrared System Low at Risk of Missing Initial Deployment Date, U.S. General Accounting Office, Feb. 2001. (http://www.gao.gov/cgi-bin/getrpt?GAO-01-6)