Current Context : India launched its fourth SSBN, known as S4*, adding to its nuclear deterrence capabilities.

• This follows the launch of INS Arihant and INS Arighat, which are already in service, and Aridhman (S4), which is undergoing sea trials.​

About S4*

• The S4* features around 75% indigenous components, emphasizing India’s focus on self-reliance in defense.
• It is equipped with K-4 submarine-launched ballistic missiles(SLBMs) that have a range of 3,500 km, enhancing the nuclear deterrence reach.
• Global SSBN Operators: Only a few countries operate nuclear-powered SSBNs, including the US, Russia, China, UK, France, and India, reflecting their advanced technological and defense capabilities​​

Future Plans : India is also working on developing the S5 class SSBNs, which will have a larger displacement and advanced missile capabilities, expected to be ready by the 2030s.