Sept. 6 (UPI) -- The U.S. Navy announced the test launch of unarmed Trident II missiles from the USS Nebraska on Friday.
Two launches occurred on Wednesday, and two on Friday, off the coast of Southern California. The tests from the Ohio-class ballistic missile submarine were part of a Commander Evaluation Test to validate performance expectations of the Trident II strategic weapon system.
The launches are the latest in 176 successful flights of the Trident II strategic weapon system. The tests are conducted on a recurring, scheduled basis and were not in response to any world events, the Navy said in a statement.
Trident missiles, built by Lockheed Martin Space Systems, have been deployed with the American and British navies since 1990. They are regarded as improvements, in accuracy, payload, and range, over the earlier Trident C-4, and are a key element of U.S. strategic deterrence.
Originally intended to be phased out by 2024, the system recent underwent a life-extending program that will keep the missiles operational through the 2040s.
The tests this week come as the Navy attempts to use more events, live and virtual, into training to prepare ships' crews to defeat potential threats. Navy commands in the Pacific and Atlantic Oceans are working to expose surface forces to more complex and challenging training as the Navy pushes the fleet to build its warfighting skills.
"Our nation's sea-based deterrent has been a critical component of our national security since the 1960s, and this week's launches continue to demonstrate the credibility and reliability of our life-extended missiles," said Vice Adm. Johnny R. Wolfe, director of the Navy's Strategic Systems Programs, said in a Navy statement regarding this week's tests.