The Missile Defense Agency’s eye-catching floating radar returned to a Ford Island dock yesterday for replenishment of food and fuel and to perform some checks, the Navy said.

The $1 billion Sea-Based X-Band Radar platform is 240 feet wide and 390 feet long. It towers more than 280 feet from its keel to the top of the radar dome and displaces nearly 50,000 tons.

The floating radar, known as the SBX, left Ford Island on Sept. 2 following $7 million in maintenance. The vessel is expected to leave Hawaii again in January.

On Dec. 15 the SBX was used in a failed intercept test of a ballistic missile target over the Pacific Ocean.

The flight test included the successful flight of an intermediate-range ballistic missile target from the Ronald Reagan Test Site on Kwajalein Atoll in the Republic of the Marshall Islands and a long-range interceptor missile launched from Vandenberg Air Force Base, Calif.

The SBX and all sensors performed as planned, but a "kill vehicle" failed to slam into the missile target, the Missile Defense Agency said.

Adak, Alaska, was the radar’s intended home port, but the SBX has never pulled into port there, officials said. Since the "golf ball" arrived here in 2006 from Corpus Christi, Texas, for a temporary stay, it has returned frequently to Hawaii for millions of dollars in maintenance and repairs.

The powerful radar has 45,000 radiating elements within its white pressurized dome to track targets. Designed to discriminate nuclear warheads from decoys, the radar is so powerful it can detect a baseball flying through the air on the East Coast when the SBX itself is on the West Coast.

The Missile Defense Agency plans to move the SBX to Todd Pacific Shipyard in Seattle in March for $9.4 million worth of work on the vessel’s thrusters and other modifications.