A forward-deployed ballistic missile detection vessel
SBX-1 is the US Navy designation for its self-propelled radar vessel. The designation is short for Sea-Based X-Band Radar-1. The vessel started life as a CS-50 twin-hull semi-submersible drilling rig. It was built in the Vyborg shipyard in Russia in 2002. The vessel was acquired by the United States Government in 2003 and upgraded in the AmFELS shipyard in Brownsville. Among other things, its propulsion system was replaced with thrusters able to propel the vessel at speeds of up to nine knots. Large generators were installed to operate the radar and communications systems. The one large radar dome and various smaller domes were mounted on the vessel in the Kiewit shipyard in Ingleside, Texas. The antenna in the large dome has a surface area of approximately 384 square meters. The radar was built by Raytheon and operates in the X-band frequency enabling fine resolution of tracked objects. The crew of approximately 80 consists mostly of civilian contractors. The SBX-1 is associated with of the Ground-Based Midcourse Defense (GMD) system operated by the Department of Defense Ballistic Missile Defense System. The vessel is operated by the Military Sealift Command (MSC) primarily in the North Pacific Ocean and is charged with detecting incoming ballistic missiles. Being able to operate well beyond the range of US ground-based radars, it can provide early detection of missile launches from locations such as North Korea. Data from the vessel’s radar is used to guide land-based interception missiles from Alaska and California, as well as in-theater assets. In 2009 and in 2012, the SBX-1 was stationed offshore Hawaii in anticipation of missile launches by North Korea. Rumors indicate that it has once again been deployed in response to new provocations by North Korea, but the Department of Defense will not comment on its whereabouts. Original plans called for acquisition of additional similar vessels, but those plans have since been put aside. The SBX-1 is inspected by the US Coast Guard and classed by the American Bureau of Shipping.