The presence of a missile defense vessel docked at Aloha Tower, where passersby expect to see fancy cruise ships, is surely prompting some double takes. Fitted with twin domes housing 24-foot antennas, the missile telemetry ship MV Pacific Collector belongs to the U.S. Department of Transportation’s Maritime Administration and used in support of U.S. Missile Defense Agency missions. Is it here for a test of some sort?

A spokesman has confirmed something for late May: A test that will mark the first time a ground-based missile interceptor launched from California attempts to hit a “threat-representative” intercontinental ballistic missile in its midcourse over the Pacific.

At a time when North Korean missiles are being test-fired at an accelerated pace, the U.S. military is expected to closely watch this test.