State PCS - Odisha (OPSC)

• 31 Dec 2025

K-4 medium-range ballistic missile

Why in News?

India successfully test-fires 3,500‑km K‑4 Medium-Range Ballistic Missile from nuclear‑powered submarines.

Key Points

• Launch Platform: The launch was carried out from INS Arighaat, a nuclear-powered ballistic missile submarine (SSBN) of the Indian Navy, in the Bay of Bengal.
• Strategic Significance: Enhances India’s sea‑based nuclear deterrence and contributes to the nuclear triad — the ability to deploy nuclear weapons from land, air, and sea. 
• Second‑Strike Capability: The test strengthens India’s second‑strike capability, ensuring that even after absorbing an initial attack, India can respond decisively.
• DRDO Role: The Defence Research and Development Organisation (DRDO) developed the K‑4 missile, which uses solid fuel and advanced navigation systems. 
• Ballistic missiles: They are rocket-propelled weapons that follow a free-fall trajectory after launch. They can carry conventional or nuclear warheads and be launched from land, sea, or air.  
  • Based on range, they're classified as short (< 1,000 km), medium (1,000–3,000 km), intermediate (3,000–5,500 km), or long-range or intercontinental ballistic missiles (ICBMs)( > 5,500 km). 
  • Agni-V is India’s longest-range missile, an ICBM with a range of over 5,000 km.