India sent its first domestically built ballistic missile submarine (SSBN) on new trials this week ahead of an expected commissioning later this spring, according to local press reports.

INS Arihant left the Shipbuilding Centre (SBC) in the port of Visakhapatnam, on the southeastern coast of India, week for the at-sea tests, according to The Times of India.

“INS Arihant is now undergoing sea acceptance trails as it had already passed several deep sea diving drills. The submarine will be commissioned after completing all the sea trials,” Flag Officer Commanding-in-Chief of Eastern Naval Command, Vice-Admiral H.C.S. Bisht, told reporters in a press conference.

The 6,000-ton ballistic missile submarine can field 12 K-15 Sagarika with a 450 to 1,200 mile range – depending on the payload – or four intermediate range K-4 submarine launched ballistic missiles (SLBMs) with a range of 2,200 miles. The Indian Navy plans to build three to six of the submarines as a strategic deterrent platform. In a previous set of trials in March, Arihant launched a test K-4 missiles without a warhead.

The trials – for both the SLBMs and the submarine — is a big win for the domestic shipbuilding industry, Eric Wertheim — naval analyst and author of U.S. Naval Institute’s Combat Fleets of the World — told USNI News on Wednesday.

“This is an important step forward for India’s defense industrial base, nuclear deterrent, and its submarine capabilities,” he said.

“Submarine design and development has always been one of the most challenging undertakings for both governments and shipyards, and this is especially true for nuclear-powered and nuclear-armed submarines such as Arihant.”

In addition to Arihant, India has 45 other ships under construction including its first domestic aircraft carrier INS Vikrant.