India’s Ministry of Defence-owned Defence Research & Development Organisation’s (DRDO) Hyderabad-based Research Centre Imarat (RCI( and its associated Sensors Research Society (SRS) has since 2012 accelerated efforts to develop a theatre missile defence (TMD) system using the AAD endo-atmospheric interceptor, which is specifically designed for neutralising the Pakistan Army’s China-supplied solid-fuelled single-stage DF-11 (Hatf-3/Ghaznavi) 280km-range tactical ballistic missiles and the North Korea-supplied liquid-fuelled single-stage Hatf-5/Ghauri-1/Nodong-1 IRBMs, both of which are conventionally armed. Presently, the Pakistan Army deploys two Missile Groups each of the Ghauri-1 and Ghaznavi (grouped under two separate Artillery Brigades, these being the Hyderabad-based Missile Brigade South comprising Missile Groups 25, 35 and 40; and the Sargodha-based Missile Brigade North comprising the 14, 28 and 47 Missile Groups).
Though the IAF had decided to acquire TMD assets way back in 1996, it was the DRDO that first got into the act of proposing a homegrown solution, for which it initiated the development of the PAD/PDV family of solid-fuelled exo-atmospheric interceptor missiles and AAD/AD-1/-2 family of endo-atmospheric interceptor missiles—with the AAD using an active radar seeker sourced from Russia for terminal guidance (and the THALESRaytheon-supplied S-band Master-A MFCR for mid-course guidance) and the AD-1/AD-2 rounds using medium-wave infra-red (MWIR) sensors for terminal homing.
Of the 15 test-firings of such missiles that have been carried out since November 2006, the PAD was test-fired only once, while the two-stage PDV was test-fired on April 20, 2014 and February 11, 2017. The PDV, which will take at least a decade to mature, is designed to intercept MRBMs (with atmospheric re-entry speeds of 5km/second more than 500km away) at an altitude of 150km. Though the PDV will be cruising at Mach 5, it will be required to attain a peak terminal speed of Mach 11—made possible by the divert thruster placed on top of the second-stage. The divert thruster will generate high lateral acceleration for the ‘end-game’. Both the warhead and divert thruster will be fired simultaneously towards the target once they are within the acquisition range of the PDV’s combined ARSEEK Ku-band RF seeker and the MWIR seeker.
Development of the AAD endo-atmospheric interceptor missiles has witnessed greater urgency, with the AAD being test-fired on December 6, 2007; March 6, 2009; March 15, 2010; July 26, 2010; March 6, 2011; February 10, 2012; and November 23, 2012. Following a three-year interval, the AAD’s missile’s test-firings commenced on April 6, 2015 and were followed by test-firings on November 23, 2015; May 15, 2016, March 1, 2017 and December 28, 2017. The Mach 8 AD-1 is yet to be test-fired and it features all-composite rocket motor casing, MEMS-based redundant micro-navigation system (RMNS), as well as a new-generation MWIR sensor that employs semiconductors using indium gallium nitride and aluminum gallium nitride alloys for the RCI-developed 1,024-element staring focal plane arrays. The AD-2 missile’s terminal-guidance sensor will operate in the ultra-violet bandwidth to give better solar radiation rejection. The AAD’s flight trajectory is shaped through aerodynamic control out to an altitude of 35km and a distance of 200km when used for intercepting re-entry vehicles flying at 9km/second. It is able to sustain up to 30 G, thereby making it unstable. at an altitude of 35km. It stands 7.5 metres tall, weighs around 1.3 tonnes and has a diameter of less than 0.5 metres.
India’s ‘desi’ TMD system using the AAD missiles is still another five years away from maturing, pending the availability by 2020 of a full instrumented TMD test range costing Rs.1,000 crores that will be located at Machilipatnam in Andhra Pradesh (from where the AAD interceptors will be launched from underground vertical-launch cells) and at Rutland Island in the Andaman & Nicobar chain of islands, from where the to-be-targetted ballistic missiles will be launched.
The Machilipatnam-based facility will also house one L-band long-range tracking radar (a licence-built clone of the EL/M-2080 Green Pine early warning radar) along with a launch-control centre, plus a five-array S-band EL/M-2248 MF-STAR target illumination/engagement active phased-array radar that will be mounted in a shore-based structure (which will also house two-way SATCOM data-link antennae) that will bear more than a close resemblance to the island of the Indian Navy’s Project 71/IAC-1 aircraft carrier that is now undergoing fitting-out at the Kochi-based Cochin Shipyards Ltd.
In other words, the Machilipatnam-based facility will be similar in design and deployment layout to Lockheed Martin’s AEGIS ASHORE system, which can be reviewed here: