Boeing will begin maintenance and upgrade activities this week in Seattle for the Sea-based X-band Radar (SBX), which arrived in port on May 10, passing through Puget Sound and Elliott Bay.

SBX is an oceangoing radar that identifies, tracks, and assesses the flight characteristics of ballistic missile threats. It provides an advanced capability to the United States' overall ballistic missile defense system.

The U.S. Missile Defense Agency awarded Boeing a $27.1 million sole-source contract in April for the shipyard maintenance efforts, which are scheduled to be completed in August.

Boeing has been the prime contractor for the SBX since 2003 and is responsible for all development, integration, testing and operations for the vessel platform and radar.