K-4 (missile)

K-4 is a nuclear capable Intermediate-range submarine-launched ballistic missile developed by the Defence Research and Development Organisation of India to arm the Arihant-class submarines.[7] The missile has a maximum range of about 3,500 km.[5][8]

TypeIntermediate-range SLBM
Place of originIndia
Service history
In service2020s[1]
Used by Indian Navy
Production history
DesignerDefence Research and Development Organisation
ManufacturerBharat Dynamics Limited
Mass17 t (19 short tons)[2]
Length12 m (39 ft)[2]
Diameter1.3 m (4.3 ft)[2]
WarheadStrategic nuclear weapon

EngineTwo stage rocket motor[3]
PropellantSolid fuel[3]
3,500 km (2,200 mi)[4][5]
Mid-course: Inertial navigation system with GPS/NavIC satellite guidance,
Terminal: Terrain contour matching[6]
Arihant class submarines, S5-class submarines


The development of the K-4 was undertaken after facing significant difficulties in compacting similarly capable Agni-III to equip INS Arihant which has a limited 17-metre (56 ft)-diametre hull. K-4 has range comparable to Agni-III with major length reduction from 17 metres (56 ft) to 12 metres (39 ft). The gas-booster designed for K-4 was successfully tested from a submerged pontoon in 2010.[9]

Agencies responsibleEdit

The High Energy Material Research Laboratory (HEMRL) and the Advanced Centre for Energetic Materials (ACEM) of the DRDO have been involved in developing the three motors responsible for propelling the K-4, the systems responsible for separating the stages of K-4, the low-thrust boosters, the gas generator and other components. The launch system of K-4 has been developed by the Naval Systems Group of the Research and Development Establishment (Engineers).[10]


External video
  Video of K-4 missile launch

The K-4 is a submarine-launched ballistic missile which is composed of two stages.[3] The missile is reported to be 12 metres (39 ft) long with a diameter of 1.3 metres (4 ft 3 in) and weighs nearly 17 tonnes (19 tons). It can carry a warhead weighing up to 2 tonnes (2.2 tons) and is powered solid rocket propellant. The DRDO stated that the aim of the missile was to achieve a high accuracy.[2] As a countermeasure against ballistic missile defence systems, the K4 can perform three-dimensional maneuvers.[1]


The developmental testing of K-4 started in January 2010, when the missile successfully ejected from a pontoon submerged 50 metres below the surface of water and breached the surface.[11] The missile was originally scheduled to be initially tested in September 2013 from a pontoon submerged 50 feet underwater, but the test was delayed due to unspecified issues.[2][12] In the event, the first test was carried out on 24 March 2014 from a depth of 30 metres. The test was successful and the missile was tested to a range of 3,000 km. The launch took place from a pontoon submerged more than 30 metres deep in the sea off the Visakhapatnam coast. After a powerful gas generator ejected it from the pontoon submerged in the Bay of Bengal, the K-4 missile rose into the air, took a turn towards the designated target, sped across 3,000 km in the sky and dropped into the Indian Ocean.[13]

It is reported that on 7 March 2016[14] the K-4 was successfully tested from a submerged platform in the Bay of Bengal.[15]

In April 2016, it was reported that the missile was successfully tested on 31 March 2016 from INS Arihant, 45 nautical miles away from Vishakhapatnam coast in Andhra Pradesh. The missile with a dummy payload was launched from the submarine in full operational configuration. The trial was carried out with the support of the personnel of Strategic Forces Command (SFC) and the DRDO provided all the logistics. The missile was fired from 20-metre deep and covered more than 700 km before zeroing on the target with high accuracy reaching close to zero error.[14][16][17][18][19]

On 17 December 2017, an attempt to launch K-4 missile ended in a failure.[20][21] The failure was attributed to a discharged battery.[20]

A test of the K-4 was planned in October 2019 but got postponed.[22][23] A test of the K-4 missile was expected to be held on 8 November 2019,[24][22] but got postponed due to unfavorable weather conditions caused by the cyclone Bulbul.[25] A test of the missile was expected to be conducted in December 2019.[26]

On 19 January 2020, K-4 was successfully tested from a submerged platform located in the coastal waters of Andhra Pradesh.[27][28] This test was undertaken in full operational configuration during which the missile traversed a distance of over 3,500 km in approximately 21 minutes, achieving a near-zero circular error probability.[29]

Another test was successfully carried out on 24 January 2020.[30] This was the final developmental test of K-4 and the missile was ready to enter serial production.[1][31]

See alsoEdit


  1. ^ a b c "Sub-launched K-4 ready for induction". The New Indian Express. 25 January 2020. Retrieved 25 January 2020.
  2. ^ a b c d e "Longest Range Ballistic Missile All Set for Undersea Launch". The New Indian Express. 10 December 2013. Retrieved 19 August 2019.
  3. ^ a b c "India Test Fires Nuke Capable SLBM K-4 Secretly". The New Indian Express. 9 March 2016. Retrieved 29 January 2020.
  4. ^ "K-4 Missile Set for 'Secret' Test". THE NEW INDIAN EXPRESS. 4 March 2016. Retrieved 4 March 2016.
  5. ^ a b "India successfully test-fires underwater missile". The Hindu. 27 January 2013. Retrieved 27 January 2013.
  6. ^ CSIS. "Sagarika/Shaurya". Missile Threat. CSIS. Retrieved 28 January 2020.
  7. ^ Diplomat, Ankit Panda, The. "India Inches Closer to Credible Nuclear Triad With K-4 SLBM Test". The Diplomat. Retrieved 26 March 2016.
  8. ^ http://www.nasic.af.mil/LinkClick.aspx?fileticket=F2VLcKSmCTE%3d&portalid=19
  9. ^ Subramanian, T. S. (28 January 2011). "DRDO plans another K-15 missile launch". The Hindu. ISSN 0971-751X. Retrieved 19 August 2019.
  10. ^ "Key components of K-4 missile designed, developed in Pune". The Indian Express. 21 January 2020. Retrieved 25 January 2020.
  11. ^ Unnithan, Sandeep (20 November 2010). "The secret 'K' missile family". India Today. Archived from the original on 14 June 2018. Retrieved 17 September 2019.
  12. ^ "India's K-4 SLBM awaits first launch". Jane's. 27 August 2013. Retrieved 10 December 2013.
  13. ^ Panda, Ankit (13 May 2014). "India Inches Closer to Credible Nuclear Triad With K-4 SLBM Test". TheDiplomat.
  14. ^ a b "EXPRESS EXCLUSIVE: Maiden Test of Undersea K-4 Missile From Arihant Submarine". The New Indian Express. Retrieved 12 April 2016.
  15. ^ "K-4 Missile Test A Roaring Success". The New Indian Express. Retrieved 27 March 2016.
  16. ^ "India tests most ambitious nuclear missile". indiatoday.intoday.in. Retrieved 13 April 2016.
  17. ^ "Nuclear-capable K-4 ballistic missile tested from INS Arihant - Firstpost". Firstpost. 13 April 2016. Retrieved 13 April 2016.
  18. ^ Diplomat, Ankit Panda, The. "India Successfully Tests Intermediate-Range Nuclear-Capable Submarine-Launched Ballistic Missile". The Diplomat. Retrieved 13 April 2016.
  19. ^ "DRDO's nuclear capable K-4 underwater missile test-fired again, this time from INS Arihant: Report". International Business Times, India Edition. 9 April 2016. Retrieved 13 April 2016.
  20. ^ a b Pubby, Manu (24 December 2017). "Setback for Indian missile programme: Two failures in a week, submarine version stuck". The Print. Retrieved 19 August 2019.
  21. ^ Rout, Hemant Kumar (3 January 2018). "DRDO lines up crucial trials of Agni-V and K-4 missiles". The New Indian Express.
  22. ^ a b "India to test-fire 3,500 km range K-4 nuclear missile". Asian News International. 6 November 2019. Retrieved 6 November 2019 – via The Economic Times.
  23. ^ "Submarine launched ballistic missile (SLBM) K-4 test imminent" (PDF). DefenceNews. 25 October 2019. Archived (PDF) from the original on 1 November 2019. Retrieved 1 November 2019 – via Defence Research and Development Organisation.
  24. ^ "Four nuclear capable missiles lined up for test this month". The New Indian Express. 4 November 2019. Retrieved 4 November 2019.
  25. ^ Pubby, Manu (29 November 2019). "Critical test for submarine-launched nuclear missile this weekend". The Economic Times. Retrieved 29 November 2019.
  26. ^ Pubby, Manu (30 November 2019). "Submarine launched K4 missile test now likely in mid December". The Economic Times. Retrieved 30 November 2019.
  27. ^ Peri, Dinakar (19 January 2020). "India successfully test-fires 3,500-km range submarine-launched ballistic missile K-4". The Hindu. ISSN 0971-751X. Retrieved 19 January 2020.
  28. ^ "India successfully test-fires nuclear-capable K-4 ballistic missile off Andhra Pradesh coast". Asian News International. 19 January 2020. Retrieved 19 January 2020.
  29. ^ "India successfully test-fires 3,500 km nuclear-capable missile K-4". The New Indian Express. 20 January 2020. Retrieved 20 January 2020.
  30. ^ "India successfully test-fires K-4 submarine-launched nuclear capable missile". Press Trust of India. 24 January 2020. Retrieved 25 January 2020 – via The Economic Times.
  31. ^ "Arihant's N-capable missile 'ready to roll'". The Times of India. 24 January 2020. Retrieved 25 January 2020.