Agni-II (IAST: Agnī ""Fire"" also the Vedic fire god in Hinduism), is the second strategic ballistic missile of Agni (missile) family envisaged to be the mainstay of the Indian missile-based strategic nuclear deterrence. The Agni-II is a medium-range ballistic missile (MRBM) with two solid fuel stages and a Post Boost Vehicle (PBV) integrated into the missile's Re-entry Vehicle (RV). The Agni's manoeuvring RV is made of a carbon-carbon composite material that is light and able to sustain high thermal stresses of re-entry, in a variety of trajectories. The Agni-IIA is a more advanced version of Agni-II, albeit with more sophisticated and lighter materials, yielding a better range and operating regime. Agni-IIA was later renamed as Agni-IV plugging the gap between Agni-II and Agni-III. While the first test of Agni-IV in December 2010 was a failure, the second test flight in November 2011 was a success Agni-II, developed as part of medium- and long-range Agni series of missile systems, has already been inducted into the Armed Forces.