K-4 Missile:- India’s submarine launched ballistic missile with a range of 3500 km

K-4 is a nuclear capable intermediate range submarine-launched ballistic missile under development in the 2000s–2010s byDefence Research and Development Organisation of India to arm the Arihant-class submarine and to complement or replace Sagarika (missile) K-15 Sagarika missile.

Named after Kalam, a secret family of advanced weapons is taking shape but the Government is yet to decide on the induction of their land-based variants.

In a dramatic breakthrough in its nuclear offensive capability, India has successfully tested a submarine-launched ballistic missile (SLBM) with an eventual range of 3,500 km. Tested secretly off Visakhapatnam in January  last year, the 10-m long and 1.3-m wide missile emerged from a pontoon submerged 50 m underwater and breached the surface. Painted black and white so that it can be distinguished in water, it has passed a critical parameter.

Named after India’s missile man, former President APJ Abdul Kalam, the nuclear-tipped K-4 is quite significant in a batch of new-generation counter-strike strategic missiles. The top secret indigenous “K” missiles are faster, lighter and stealthier. They also make India only the sixth country to develop undersea strategic missiles.

A second firing, conducted in Visakhapatnam  which has  revalidate a critical parameter-the ability of a 20-tonne projectile to withstand 50 kg of water pressure and eject from a submerged launcher before engaging its rocket booster. What makes an SLBM relevant in the Indian context is that it is part of the third leg of the nuclear deterrent (air and ground-launched weapons being the other two) and the ideal invulnerable second strike weapon stated in the nuclear doctrine. Defence officials say a long range SLBM like the K-4 will enable an Indian nuclear submarine lurking in the Bay of Bengal to target China and Pakistan simultaneously. Launched last year, India’s first indigenous nuclear-powered submarine Arihant has been designed to carry four K-4s or 12 of the 750-km range K-15s.
DRDO officials say that the K-4 will be ready for induction before the end of the decade. This is because most technologies, including the sophisticated guidance packages, were already perfected while developing the shorter range K-15 SLBM. Defence officials, however, are cautious because despite a history of missile expertise, Russia has witnessed multiple failures of its new Bulava SLBM. In the works is an as yet unnamed longer-legged variant of the K-4 with a 5,000-km range. The 12-m long missile is meant to arm future nuclear submarines.

But while the DRDO parades its Agni and Prithvi missiles on Republic Day, it will not even acknowledge the existence of any of these “black projectsâ€? that have been cloaked under the Advanced Technology Vessel Project (ATV) that builds the Arihant class of nuclear submarines.

By 2008, the missile was successfully test fired seven times, and tested to its full range up to four times. The tests of 26 February 2008, were conducted from a submerged pontoon 50 metres (160 ft) beneath the surface off the coast of Visakhapatnam. A land-based version of the K-15 Sagarika was successfully test-fired on 12 November 2008. A full range test of the missile was done on 11 March 2012. The twelfth and final development trial of the missiles was conducted on 27 January 2013. According to DRDO Director General V. K. Saraswat, the missile was again tested for its full range of 700 km and met all its objectives with a single digit impact-accuracy.The test will be followed by integration of the missile with INS Arihant.

The K-4 SLBM was one of India’s Defense Research and Development Organization’s (DRDO) most secretive projects and is intended to succeed the K-15 underwater-launched ballistic missile. Once fully tested and proven to be reliable, the K-4 will be installed on India’s new INS Arihant – its first indigenously developed nuclear submarine.

The K-4 is tailor-made for second-strike purposes. According to the New Indian Express, the missile has the advantage of a hypersonic cruise speed and uses an innovative system of weaving in three dimensions as it flies towards its target, making it an exceptionally difficult target for anti-ballistic missile systems and other air defense systems. Other features of the K-4 include its high accuracy, with an alleged near-zero circular error probable (CEP).

The abilities of the K-4 are set to allow India to deter China with greater credibility. While Pakistan is a concern for India, its relative lack of strategic depth and India’s massive conventional advantage have pushed Indian thinking on nuclear matters towards China in recent year. With the K-4-equipped INS Arihant, India has a survivable second-strike capability against China. The Arihant can reportedly carry four K-4 missiles (or 12 of the less-advanced K-15 missiles). The first Arihant-class submarine is undergoing sea trials in 2014 and will be succeeded by three additional boats, expected to be in commission by 2023.