The U.S. Navy test fired four Lockheed Martin-built Trident 2 D5 ballistic missiles in early June from the submerged submarine USS Maryland in the Atlantic Ocean, Sunnyvale, Calif.-based Lockheed Martin Space Systems said in a June 22 press release.

The tests, conducted June 8 and 9, culminated with the 134th consecutive successful test flight of the Trident 2 D5 missile since 1989, Lockheed Martin said.

The missiles were launched as part of a Follow-on Commander’s Evaluation Test. Each missile was converted to a test configuration using a test missile kit provided by Lockheed Martin that contains range safety devices and flight telemetry instrumentation.

The D5 missile was first deployed in 1990 and currently is aboard U.S. Ohio-class submarines and British Vanguard-class submarines.