India has successfully completed the critical static testing of the K-5 submarine-launched ballistic missile (SLBM) Stage-2 rocket motor, marking a major milestone in its strategic defence capabilities. The test, conducted on 12 September 2025 at the Advanced Centre for Energetic Materials (ACEM) in Hyderabad, validated the advanced composite motor technology and large-scale casting capabilities developed indigenously. The K-5 SLBM, designed with a three-stage solid-fuelled system and composite materials, is set to enhance India’s undersea nuclear deterrence by providing a credible second-strike capability from Arihant-class nuclear submarines. The successful static test confirms the reliability of the propulsion system, including stable combustion, precise thrust-vector control, and robust structural integrity, all monitored through over 250 sensors. This achievement underscores India’s progress in missile propulsion and materials engineering, reducing dependence on foreign systems and strengthening the sea-leg of its nuclear triad. The K-5 missile is expected to carry a nuclear payload and support Multiple Independently Targetable Reentry Vehicle (MIRV) technology, further bolstering India’s strategic reach and deterrence posture.