According to Wikipedia: "The Arihant class (Sanskrit, for Slayer of Enemies) is a class of nuclear-powered ballistic missile submarines being built for the Indian Navy. The lead vessel of the class, INS Arihant, has been launched for sea trials by August 2013. Four vessels are being built and are expected to be in commission by 2023. The Arihant-class vessels are India's first indigenously designed and built nuclear submarine."