India Tests K-4 Missile, With 3,500-km Range, From Nuclear-Powered Submarine

In a big flex of its nuclear capabilities, India has tested an intermediate-range ballistic missile launched from a nuclear-capable submarine. The K-4 missile was test-fired from the nuclear-powered submarine INS Arighaat in the Bay of Bengal on Tuesday. The test was conducted off the coast of Vishakhapatnam.

Designed to hit targets 3,500 km away, the missile provides a massive boost to the sea-based nuclear attack capability of the forces.

The K-4 submarine-launched ballistic missile (SLBM) was commissioned into the Indian Navy on August 29, 2024, making India part of a small group of nations capable of firing a nuclear missile from land, air, and undersea.

Derived from the Agni-III land-launched missile, it is the country's longest-range sea-launched strategic weapon. The land version of the missile has been modified for sea launch, including the ability to pop out of a submarine launch silo, bubble up to the ocean surface, and then activate its rocket motor to blast into the air.

The missile has been built to deliver a 2.5-ton nuclear warhead and can be launched from India's Arihant-class submarines.

K-4 is the stealthiest leg of India's nuclear triad, since ballistic missile submarines like the Arihant-class are built to lurk around in complete silence in unknown stretches of ocean for extended periods on "deterrence patrols."

The 'K' in the K-series of missiles is a tribute to APJ Abdul Kalam, who played a key role in India's Integrated Guided Missile Development Program (IGMDP).