Visakhapatnam, July 26 - Prime Minister Manmohan Singh's wife Gursharan Kaur launched the country's first indigenously designed and built nuclear-powered attack submarine, INS Arihant, here Sunday.

The INS Arihant will be commissioned in the Indian Navy after extensive outfitting and sea trials. It is the first of three such vessels to be built in the country and marks a quantum leap in India's shipbuilding capabilities.