Space-Based Infrared System

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The Space-Based Infrared System (SBIRS) (pronounced "sibirs") is a consolidated system intended to meet United States infrared space surveillance needs through the first two to three decades of the 21st century. The SBIRS program addresses critical warfighter needs 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) and low Earth orbit (LEO), sensors hosted on satellites in highly elliptical orbit (HEO) and ground data processing and control. SBIRS ground software integrates infrared sensor programs of the U.S. Air Force (DSP) with new IR sensors. SBIRS was experiencing cost overruns as of 2003 (and more recently as of late 2005) and is now expected to cost over $10 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 of 2005, following the third SBIRS Nunn-McCurdy violation, the government decided to compete GEO 4 and 5, with an option to buy GEO 3 contingent on the performance of the first two. Additionally, the government started a potential SBIRS High replacement program and proposals are currently being written (as of late June, 2006).

Contents 1 Background 2 SBIRS High 3 SBIRS Low 3.1 Original SBIRS Low 3.2 Space Tracking and Surveillance System 4 Ground segment 5 Sources

[edit] 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). 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

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.

[edit] SBIRS High

SBIRS High (also now simply referred to as "SBIRS") 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. SBIRS High is in the engineering and manufacturing development phase, with a scheduled first launch for SBIRS GEO currently scheduled for the 2007 time frame.

Both SBIRS HEOs have been delivered to the government.

The prime contractor for SBIRS is Lockheed Martin, with Northrop Grumman as the major subcontractor. Lockheed Martin also provides the satellite for SBIRS GEO.

[edit] SBIRS Low

Note: The SBIRS Low contract is now managed by the Missile Defense Agency (MDA) and has been subsequently renamed to the Space Tracking and Surveillance System (STSS).

[edit] Original 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.

[edit] Space Tracking and Surveillance System

In 2001, the Missile Defense Agency assessed the programs needed for a national ballistic missile defense system (BMDS) and found that they were lacking in the relatively new arena of space. The MDA decided to absorb the SBIRS Low constellation in its very early stages of development and renamed the program the Space Tracking and Surveillance System (STSS). This transition changed the direction of the program somewhat, but the overall mission remained the same--detection and tracking of ballistic missiles through all of its phases of flight.

[edit] Ground segment

The ground segment of SBIRS consists primarily of the Mission Control Station (MCS) at Buckley AFB, Aurora, Colorado, the Mission Control Station Backup (MCSB) at Schriever AFB, Colorado Springs, Colorado, and the Survivable Mission Control Station (SMCS). In addition, the Joint Tactical Ground Stations (JTAGS) provide deployable downlinks for SBIRS data.

[edit] Sources

• Space-Based Infrared System Low at Risk of Missing Initial Deployment Date, U.S. General Accounting Office, Feb. 2001.
• [1]
• Tactical Ballistic Missile Warning, US Strategic Command