The U.S. Navy confirmed between September 17 and September 21, 2025, that its Strategic Systems Programs successfully conducted four test flights of the Trident II D5 Life Extension (D5LE) Submarine-Launched Ballistic Missile (SLBM) off Florida's east coast. One of these tests on Sunday evening was visible from Puerto Rico, illuminating the night sky, according to a statement from the U.S. Navy. These tests represent the 197th successful flight test of the Trident II D5 Strategic Weapon System, which has been in service since the 1980s. A 2017 life-extension upgrade is expected to maintain the system's service life into the 2040s, the Navy statement added. Separately, footage captured from Puerto Rico reportedly showed a nuclear submarine, likely from the U.S. or Royal UK Navy, test-firing a UGM-133 Trident II D5 Submarine-Launched Ballistic Missile in the North Atlantic on September 21, 2025. This launch was reported to potentially carry a hypersonic glide vehicle or an unusual payload, though neither the U.S. Navy nor the Royal Navy have issued official statements regarding this specific event. The U.S. and UK are the only nations equipped with the Trident II D5 SLBM.
