Among the sleek $1 billion destroyers in Pearl Harbor, one ship strikes an incongruous pose.

Noticeably listing, the decommissioned 603-foot amphibious assault ship USS Tripoli has streaked sides clearly in need of fresh paint.

Its aircraft carrierlike deck has been cleared of helicopters, and beige tents and large satellite antennas have sprouted in their place.

But the down-on-its-luck-appearing ship, decommissioned in 1995, has a high-tech role as a launch platform with the nation's developing ballistic missile defense program.

The Tripoli was recently towed off Kaua'i to launch a "Scud-like" missile that was successfully intercepted by a Terminal High Altitude Area Defense missile on Oct. 26. The interceptor was launched from the launch complex at the Pacific Missile Range Facility.

The Tripoli was used in a series of tests this year, and is usually more than 100 miles off Kaua'i during a launch, according to the Missile Defense Agency.

Officials said the Tripoli would be towed back to the San Francisco Bay Area after the latest test and return again to Pearl Harbor in the late spring.

In December 2006, the odd-looking ship with its tentlike structures drew curious stares as it passed beneath the Golden Gate Bridge.

It arrived at Pearl Harbor in January this year, and departed for the Pacific Missile Range Facility operating area in mid-January for the first of three flight tests.

On Kaua'i, there is not a land-based target launch site that would support the terminal phase high-altitude testing, the Missile Defense Agency said. The operation of the Tripoli as a mobile launch platform costs about $600,000 annually.

The Missile Defense Agency said the ship's list is intentional for maintenance or tests on launch equipment.

The Tripoli earned nine campaign stars during the Vietnam War. In the 1991 Gulf War, the Tripoli hit an Iraqi mine that ripped open a 16-foot hole below the waterline, but the ship was repaired.

Among those who have served aboard the Tripoli is Adm. Robert Willard, commander of U.S. Pacific Fleet, which has its headquarters at Pearl Harbor. Willard commanded the ship from September 1994 to June 1995.

"When she was commissioned in 1966 — or even when she was decommissioned 29 years later — I'll bet no one imagined this is what USS Tripoli would be doing now," Willard said. "This ship is continuing to make contributions toward our national security."