MissileThreat.com

Country:	USA
Basing:	Sea
In Service:	Exp. 2005

Details

The Sea-Based X-Band Radar (SBX) consists of an advanced radar system mounted on a floating platform. Once operational, it will be able to track, discriminate, and assess long-range ballistic missiles as part of the Missile Defense Agency’s Ground-Based Midcourse Defense (GMD) system. It will be located just off the coast of Alaska and will be linked to 10 ground-based interceptor missiles deployed at Fort Greely in Alaska and Vandenberg Air Force Base in California.

 

SBX, in many ways, is the offspring of the Ground Based Radar-Prototype (GBR-P), which has served as the fire control radar for flight and intercept tests at the Reagan Test Site since 1999. On August 1, 2002, MDA awarded a $31 million contract to Boeing to oversee development of its new sea-based radar system. At present, Boeing is building the floating platform, Raytheon is developing the X-band radar, and the Harris Corporation is providing systems engineering, integration services, and satellite communications equipment. The SBX team has applied many of the lessons learned from the GBR-P program, resulting in significant risk reduction and cost efficiency. The entire project will cost approximately $900 million.

 

MDA had initially planned to build a ground-based X-band radar, but decided to go with the greater range and mobility of a sea-based system. SBX’s floating platform, a modified oil-drilling vessel, is being designed for exceptional stability in high winds and storms. Measuring 240 feet wide and 390 feet long, the vessel will include a power plant, bridge and control rooms, living quarters, storage areas, and enough floor space and infrastructure to support the X-band radar. The platform’s mobility will allow MDA to relocate SBX to accommodate future “layers” of the Ballistic Missile Defense System.

 

The X-band radar itself, which will sit on top of the floating platform, will be the largest, most sophisticated phased array, electro-mechanically steered X-band radar in the world. It will consist of thousands of antennae driven by transmit/receive (T/R) modules. T/R modules are multi-functional circuits that can transmit, receive, and amplify signals. In the X-band radar, they will provide the full fire control sensor functions for the Ground-Based Midcourse Defense system, including search, acquisition, tracking, discrimination, and kill assessment. The radar will be capable of distinguishing between objects as close as 15 centimeters.

 

After the radar has been mounted on the vessel, the entire structure will measure over 280 feet from the keel to the top of the radar’s dome, displacing 50,000 tons of water. To put this in perspective, SBX will be roughly the size of two football fields. A commercial C-band satellite will establish communications between the platform and shore facilities. It will take between 50 and 55 people on the platform and an addition 30 to 40 on shore to maintain the system.

 

Once operational, SBX will use its finely focused beam to track an incoming ballistic missile through space during the 20 or so minutes that it is outside the Earth’s atmosphere. The radar will transmit detailed tracking information to GMD’s command unit, which will calculate a fire mission and launch its Ground-Based Interceptor (GBI) missile. As the GBI streaks towards the threat, SBX will distinguish between warheads and decoys, ensuring the interceptor’s accuracy. The radar will continue to relay updated targeting information after GBI launches its Exoatmospheric Kill Vehicle (EKV), which will proceed on a collision-course trajectory toward the target. SBX will determine whether or not the EKV destroyed the warhead, and prepare to support a second launch if necessary.

 

The one drawback of SBX is that X-band radars, like all other radars, cannot see over the curvature of the earth, known as the “radar horizon.” SBX’s ability to detect incoming missiles (and discriminate between warheads and decoys) depends completely on where the radar is located in relation to the incoming missile. Thus, the closer to rouge nations and terrorist-sponsoring states that SBX is positioned, the better the odds that GMD will be able to complete a successful interception.

 

On August 16, 2003, MDA announced its decision to deploy the SBX platform just off the coast of Adak, Alaska. Located on the western end of the Aleutian Islands, Adak is ideal for SBX because it will allow the system extra time to collect data on incoming threats from Asia. MDA considered sites in Washington and California as well, but concluded that locations on the continental U.S. would not give GMD enough time to intercept its targets. Adak served as a base of operations during World War II, housing 6,000 naval personnel and their families. Its existing Army infrastructure includes a 7,900-foot runway, a deep-water port that is ice-free year-round, two piers, a 22 million-gallon fuel storage tank, and barracks.

 

The X-band radar is currently being constructed in Brownsville, Texas. Once completed, it will be installed on the oil-drilling platform, which is being built in Norway. Sea trials will take place in the Gulf of Mexico before SBX moves to its primary base in Adak, Alaska. MDA plans for the SBX platform and radar to be fully integrated and deployed by December 2005.

 

 

Sources

 

Arms Control Association.
Dunford, Bruce. “Pentagon Releases EIS On Missile Defense Radar Platform Off Oahu.” Associated Press, 15 July 2003.
GlobalSecurity.org.
Harris Corporation.
Missile Defense Agency.
Pemberton, Mary. “Adak Chosen For Missile Defense System Radar.” Associated Press, 15 August 2003.
Raytheon Company.
Selinger, Marc. “Platform For MDA’s Sea-Based X-band Radar Nears Delivery.” Aerospace Daily, 11 April 2003.
“Harris Awarded $7.7 Million Contract By Sea-based X-band Radar.” Space Daily, 19 September 2003.
Tuinstra, Rachel. “Department of Defense Picks Alaska for Sea-Based Test X-band Radar.” The Seattle Times, 16 August 2003.

SBX Modifications Scheduled for 2006

June 7, 2005 :: NTI :: News

The Missile Defense Agency plans to expand the Sea-Based X-Band Radar’s ability to communicate with missile defense systems other than the ground-based midcourse defense system, reports NTI. The expansion is scheduled for early in FY 2006.
        The SBX, currently being constructed in Corpus Christi, Texas, is an advanced radar system mounted on a semi-submersible oil-drilling rig. It will eventually be deployed from Adak, Alaska, and will be used to aid interceptors in homing in on enemy missiles over the Pacific. (Article, Link) 

» Missile system details for: Sea-Based X-Band Radar (SBX)

Dome Installed on SBX Radar

May 17, 2005 :: The Missile Defense Agency :: News

The Sea-Based X-Band Radar has now completed its major assembly with the addition of the radar’s protective “radome.” The radome weighs 18,000 pounds, stands over 103 feet high, and is 120 feet in diameter. Made entirely of a high-tech synthetic fabric, the radome is supported by air pressure alone and can withstand winds more than 130 miles per hour. The entire SBX sits on a large, converted oil rig.
        The SBX, currently being constructed in Corpus Christi, Texas, will eventually be deployed from Alaska, and will serve as an integrated radar for the ground based midcourse defense system. Although the SBX cannot see past the horizon, it would be used for looking up, to aid interceptors in homing in on missiles in space above the Pacific—that is, those headed from locations such as North Korea toward the United States. (Article, Link) 

» Missile system details for: Sea-Based X-Band Radar (SBX)

SBX Radar Base Chosen

August 15, 2003 :: Department of Defense :: News

The Missile Defense Agency has announced Adak, Alaska, as the basing location for the Sea-Based X-Band (SBX) radar, a floating platform which will be integrated with the Ground Based Missile Defenses at the Fort Greeley site. The SBX vessel is a modified oil drilling platform measuring 390 feet long and 250 feet high, with a displacement of 50,000 tons.
        During the last months some Alaskan towns have been actively campaigning for, and others against, receipt of the base.
        The MDA completed an extensive study on the environmental impact of this and other components related to the GBD system. (Article, Link) 

» MDA’s Environmental Impact Documents

» More stories on: Sea-Based Systems, Technology

» Missile system details for: Sea-Based X-Band Radar (SBX)

Total Records: 13	« 1 [2]