The Indian Drive towards Weaponization: the Agni Missile Program
By Michael Kraig, Consultant to Federation of American Scientists
After failing to reverse-engineer a SA-2 Guideline SAM as a viable ballistic missile under Project Devil in the 1970s, India formed the Integrated Guided Missile Development Program IGMDP in 1983 with the aim of achieving self-sufficiency in missile development & production. The Department of Defense notes that "the space program supports New Delhi's missile efforts through shared research, development and production facilities." The two systems produced under the IGMDP that are most likely to be a delivery vehicle for nuclear warheads are the short range tactical missile, Prithvi SS-150 (Army) and SS-250 (Airforce), and the Agni-II Intermediate Range Ballistic Missile (IRBM).
Agni (Fire) is an Intermediate-Range Ballistic Missile (IRBM) which began development in 1979. It became part of India's Integrated Guided Missile Development Program (IGMDP) in 1983 and has a tested range of 1400-1500 km. The Agni was developed principally by the Indian Defense Research and Development Laboratory (DRDL) under the Defense Research and Development Organization (DRDO), at the Defence Research Complex at Kanchanbagh, on the periphery of Hyderabad's Old City. The Agni is built by Bharat Dynamics, which has its primary facility in Hyderabad Defense Research Complex. A second Bharat Dynamics facility in Bhanoor is probably responsible for the manufacture of the Agni's solid rocket motors. Also at the Hyderabad Defence Research Complex, the Defense Metallurgical Research Laboratory (DMRL) and the government-owned special metals industry Mishra Dhatu Nigam Ltd. (MIDHANI) provide assistance in the research and fabrication of special metals used in missile construction.
Agni I Technology Test Bed, 1979-1994
The purpose of the Agni I was primarily to test reentry vehicle technology for military use. There were three flight tests of the Agni I before the BJP came to power: 22 May 1989; 29 May 1992; 19 February 1994. The second test was a partial failure, and in 1995, India indefinitely suspended the flight test program under pressure from the United States. The suspension of production and testing might also have been due to indecision regarding the future directions of India's nuclear program, especially the pursuit of thermonuclear weapons. However, Prime Minister Gowa said in 1997 that India had no intention of giving up the program permanently.
Results: Not Fit for Efficient Weaponization. The Technological Test Beds achieved a maximum range of 1500 km, covering all of Pakistan and large areas of Southwestern China, but the combination of first-stage solid fuel and second-stage liquid fuel propulsion systems made deployment and launch operations clumsy and immobile, requiring half a day of preparation. The liquid fuel was volatile, requiring loading just before launch. Also, the rocket was fairly inaccurate (Circular Error Probability of 100 meters) and had an inefficient launch control system. The CEP of 100 meters meant that the missile would only strike within 100 meters of its target 50% of the time.
Agni II: Operational Improvements for Weaponization, 1994-1999
After the BJP renewed the program in 1998, the Agni-II was tested on 11 April 1999 to a range of approximately 2000-2200 km. The range of the missile could be altered by appropriately configuring the payload mass (i.e., constructing different size warheads). At a length of 20 meters and weight of 16 tons, the Agni-II is an improvement over its predecessor, which had a length of 21 meters and a weight of 19 tons.
At the time of the April 1999 test, Indian Defense Minister George Fernandes said the Agni missile was ready to go into production, though he did not specify the production or deployment schedule. Similarly, then-DRDO Director A.J.P. Abdul Kalam asserted that no more tests were needed to operationalize and weaponize Agni-II. This indicates that the re-entry vehicle had already been rigorously tested in its previous Agni-I technology test bed flights. However, given that two new launch pads for flight testing have been constructed in Balasore district, including the IC-4 pad at Wheeler Island that was used for the April 1999 test, it is highly likely that several more tests are being planned. It is doubtful that deployment would occur without further verification of missile accuracy and reentry vehicle performance.
Launch operations and internal missile computations have been streamlined. If inducted, Agni-II will reportedly always be in a ready-to-fire mode and can be launched within 15 minutes. Over 600 communications channels inside the rocket and in ground launch control, with 24 km of wiring, have been eliminated to allow for a single control system. There are now only 10 pairs of communications channels with one-eighth the original wiring.
The Agni-II incorporates a far more accurate terminal navigation and guidance system which constantly updates information about the missile flight path using Global Positioning System information provided by ground-based beacons. DRDO's Chief Controller of R&D (Missile division), A.S. Pillai, stated after the Agni-II test, "We have improved accuracy by a factor of at least three. It is a far more lethal missile now." A Japanese newspaper report stated that Agni-II achieved a Circular Error Probability of 40 meters, although future tests would be required to substantiate the computer simulations that India used to produce this figure.
Both stages of the Agni-II have a solid-fuel propulsion system, which allows the missile to be relatively mobile and flexible. The second-stage system was taken almost directly from India's Polar Satellite Launch Vehicle (PSLV) program and has already been extensively tested and used by the Indian Space Research Organization (ISRO). Computer simulations can draw upon ISRO's data to further refine the Agni-II.
The Agni-II would be deployed via a rail-based missile launcher, which demonstrates a potential capability for dispersal in time of a crisis for maximum survivability of the deterrent. The rail launch system disguises both the missile launcher and the separate mobile launch control center under "bogie" covers on a regular commercial goods cargo train, which can be used in most parts of the Indian commercial rail system.
For adjustments to missile trajectory during flight, which allow for higher accuracy, the second stage booster has a flex nozzle which enables alterations in the thrust vector direction. Previously, the flex nozzle has been used only in the third-stage motor of the Polar Satellite Launch Vehicle. Also to increase accuracy, the re-entry vehicle employs a terminal guidance radar operating in the C- and S-bands. Also, last minute/second adjustments have been optimized through on-board software which allow reentry velocity trimming. The data bus for the on-board navigation system has been changed to off-the-shelf commercial digital technology to allow for flexible software upgrades in future versions of the missile.
