Prithvi Defence Vehicle is a two-stage interceptor with an altitude ranging between 50-80 km

INTRODUCTION

One of the greatest threats facing India today is the increasing proliferation of ballistic missiles and weapons of mass destruction in the region. India’s nuclear-armed bellicose neighbors, namely China and Pakistan, have significant cruise and ballistic missile capabilities. China and North Korea continue to proliferate on a wide scale and could increase in the long run as the technology is transferred. A rogue nation like Pakistan make these investments because ballistic missiles provides it with the means to project power both in a regional and strategic context and a capability to launch an attack on India from a distance. However, there are several reasons to doubt that Pakistan will ever launch a ballistic missile at India. Perhaps the most important relates to attribution – a missile launch could be easily detected, and retaliation would be swift and brutal at least as far as the purpose of the Modi government in Delhi is concerned.

DRDO'S ADVANCED AIR DEFENCE SYSTEM

India has initiated a demonstrable indigenous capability in Theater Ballistic Missile Defense development, a step to predominantly protect India from enemy ballistic missile attacks. The Advanced Air Defence (AAD) "Ashwin" Missile defence technology being developed, tested by DRDO is designed to counter ballistic missiles of varying ranges namely short, medium, intermediate and long. Since ballistic missiles have different ranges, speeds, size and performance characteristics, the AAD system has an integrated, “layered” architecture that provides multiple opportunities to destroy missiles and their warheads before they can reach their targets. Due to a realistic threat perception from its chief adversaries Pakistan and China, the need for a comprehensive and convincing protective cover became imperative.


Experts also believe that an effective missile defense infrastructure will provide India space for limited wars against China and Pakistan. China is superior in its ballistic missiles force level while on the other hand Pakistan's ritual flaunting of its nuclear capability and a belligerent 'First Use' policy has left India but with no choice to develop a deterring shield to defuse such a dangerous situation. The program consists of a two-tiered architecture consisting of the Prithvi Defence Vehicle (PDV) missile for Exo-atmospheric (Outside the atmospheric regime) interception and the Advanced Air Defense (AAD) Missile for Endo-atmospheric (within the atmospheric regime) interception. The two-tier system is intended to intercept ballistic missiles at distances of over 600 km. In the Phase-1 Ballistic Missile Defense (BMD) program development, interceptors fly at 4.5 Mach supersonic speeds to tackle hostile missiles with a 2,000 km strike range. The Phase-2 BMD program will intercept Intercontinental Ballistic Missiles (ICBM) with 5,000 plus Km range with interceptors flying at Mach 6-7 hypersonic speeds. The third and the final layer is planned to tackle low-flying cruise missiles, artillery projectiles and rockets in line with the overall aim to achieve “near 100% kill or interception probability”.
The system is designed so that incoming missiles can be tracked and destroyed both inside (Endo) and outside (Exo) the earth's atmosphere
The deployed system will consist of multiple launch vehicles, support equipment such as the indigenous "Swordfish" Long Range Tracking Radar, Launch Control Centers (LCC) and the Master Mission Control Center (MCC). These systems will be geographically distributed evenly to cover vulnerable locations such as metropolises, defense industries, defense bases, nuclear installations, weapons stations etc., and will be connected by a sophisticated secure communication network.

HOW IT WORKS


The AAD interceptor comprises the lower tier, and the higher-altitude, two-stage Prithvi Defence Vehicle (PDV) interceptor currently comprises the upper tier. Like the U.S.Patriot system, both of these Indian systems intercept ballistic missiles in the so-called terminal phase, in which the incoming missiles are descending toward their target. The AAD interceptor uses an explosive warhead to destroy the target missile as the interceptor approaches it. In contrast, most U.S.missile defense systems, including the Ground-Based Mid-course Defense and sea-based Aegis systems, rely on “hit-to-kill” interceptors that destroy a target solely via impact. India first tested the AAD interceptor in December 2007 and has subsequently conducted 8 successful tests.

The Indian Ballistic Missile Defence System is said to be far superior to the US Patriot Missiles

Typically ballistic missiles follow a Three-phased trajectory path: boost, mid-course and terminal:

There are three phases during which this technology could plausibly target a missile - the boost phase (initial rocket launch and ascent), the mid-course phase (while the missile is in sub-orbital flight), and the reentry phase (which is when the missile is diving back into the atmosphere towards its target). The boost phase is theoretically easy to target, but requires close proximity, an extremely fast launch cycle, and an insane amount of acceleration - remember, the system is trying to catch a good-sized rocket headed for Low Earth Orbit within 60-300 seconds. The re-entry phase is a poor option because the missile is already on-target -blowing up a nuclear or chemical rocket might just drop the warhead slightly outside of town as opposed to on the city center. That leaves the mid-course phase, which is the preferred target point.

The system’s architecture includes:

  • deployment of both endo and exo atmospheric kill vehicles, integrate exo and endo-atmospheric systems to offer a hit-to-kill probability of 99.8 per cent;
  • networked sensors (including space-based) and ground and future sea-based radars for target detection and tracking;
  • ground and sea-based (future development) interceptor missiles for destroying a ballistic missile using either the force of a direct collision, called “hit-to-kill” technology, or an explosive blast fragmentation warhead;
  • command, control, battle management, and communications network providing the operational commanders with the needed links between the sensors and interceptor missiles;
  • deployment of key early warning radar installations across the country to protect potential threat perceptions;
  • future sea based radars located in the Indian Ocean to support flight testing and actual defensive operations;

MAJOR SUCCESS

On 23 November 2012 the AAD missile test for the first time was tested in a hit-to-kill mode. During the test, the target missile (modified Dhanush missile) was simulating the final phase of the trajectory of ballistic missiles with a range of 1,500 km, such as Pakistan’s Ghauri missile. At the end of over five minutes of heightened suspense at the Launch Control Center (LCC) on Wheeler Island, the Prithvi interceptor missile cut into the path of the incoming “Enemy” missile, knocked it out and also pulverized it with its new manoeuvrable warhead. Before this test, DRDO had mostly tested, near-miss or zero-miss acquisition of targets. With this system, an ABM missile blows itself up some nine meters from its targets. However, the hit-to-kill capability will enable the interceptor to directly destroy hostile targets. DRDO has indigenously developed key Radio Frequency seeker technologies and sophisticated digital processing software.
India is now only the fourth country after Russia, Israel, and the US to have successfully tested a BMD system
The former Program Director of DRDO Dr. V.K. Saraswat had to say this after the test “Our strength is in the software, in the ballistic missile defence shield, if there are glitches in the software, it cannot be excused. It has to work perfectly. There are a million lines of code. The on-board software runs in real time in the interceptor missile.” The test has proved the capability of DRDO to handle multiple targets with multiple interceptors simultaneously. The complete radar systems, communication, networks, launch computers, target update systems, and state-of-the-art avionics were successfully proven in this mission.
This is a remarkable achievement considering that only five countries have demonstrated this capability
The Advanced Air Defence (AAD) system can provide a permanent presence and discourage Pakistan or China from believing they can use ballistic missiles to coerce or intimidate India.In times of crisis, we can surge mobile missile defence capabilities into specific regions to enhance deterrence and, if a missile is launched, improve protection of critical assets and limit damage over a wide area. The ultimate goal of missile defence is to convince adversaries that ballistic missiles are not militarily useful or a worthy investment and place doubt in the minds of potential aggressors that a ballistic missile attack against India cannot succeed and would be detrimental and would have disastrous consequences.

The Chinese and Pakistani reaction to Indian missile defense developments is not yet clear, the new capabilities and counter-capabilities add to the already vexed issue of arms race in the region, Therefore, ballistic missile proliferation in India’s neighborhood requires the development of a more capable missile defense system. According to DRDO, AAD has already demonstrated a capability to intercept ballistic missiles with a range of 1,500 kilometers.

RARE FAILURE

India's ballistic missile interceptor failed on its tenth test on 6th April 2015 being unable to reach its target, in fact, the missile nose-dived within a couple of seconds after it took off from the mobile launcher. The AAD interceptor missile was fired from Wheeler Island off the coast in Odisha, but plummeted into the Bay of Bengal seconds after lift-off. DRDO can take solace that this failure was not a major setback since the missile did not encounter any technical snags in the sub-systems as the interceptor perished within seconds of the launch. The AAD missile is 7.5 meters tall and weighs around 1.2 tonnes.

"It took off as planned but did not reach the target.We are analysing the data," said MVKV Prasad test range director of DRDO . This test was against an electronic target to validate the missile capability.With the latest mission, the DRDO has tested the missile interceptor 10 times with eight of the tests being successful.The missile had last failed to hit the target missile during a similar test from the same defence base on July 26, 2010.

NOTABLE CHALLENGES

1) The technical challenges related to the development of such a sophisticated system was underestimated by DRDO just as GTRE did for the Kaveri Jet engine program. Hence, it has taken an inordinate amount of time for the system to mature as a credible deterrent system, and it requires a lot of money, time and man-hour effort to see it through before actual deployment. For almost 20 years, the United States has poured money into developing a missile defense system that would be capable of shooting down ICBMs and cruise missiles before they impact their launch targets. Despite the effort, the system has never worked. The Russians have rather primitive systems and the Chinese are not in the game at all. On the other hand, one of the reasons Israel’s Iron Dome system works is because the insurgents it defends against can’t hurl missiles many missiles into Israeli airspace in a matter of minutes and the rockets are also of Soviet vintage. Even so, it’s more of a psychological protective measure than an effective one.

2) Qualitatively it is risky to predict a positive outcome of the current anti missile capabilities since it involves high costs and technological complexities to demonstrate definitive target termination ratification, since a 2000 km range ballistic missile launched in the regular trajectory will have high velocity of more than Mach 9-10, such a scenario has not been tested yet, because unfortunately India at present does not have any missile which would mimic such a target vehicle at this speed and range. It may be also inferred that DRDO may be constrained to conduct such tests on account of range limitations.

3) In all the tests, Prithvi missile was used as the attacker missile which simulated the trajectory of a 600 km range missile. This missile has an actual range of 350 km. Despite the fact that Prithvi’s trajectory was altered to simulate a missile with a longer range, it does not simulate a longer range missile as claimed.. Firstly, the re-entry velocity of Prithvi is very low. Though DRDO claims to have increased the re-entry velocity by adding additional boosters, it is not clear whether it attained the required velocity to imitate a longer range missile.

4) The interceptor should constantly maintain a specific speed of Mach 4.5 or more and the closing speed before interception, should be at 2 km/sec.

5) The ballistic coefficient of Prithvi could be lower due to the larger surface area of the re-entry body unlike that of a separating warhead especially if the system is dealing with Multiple independently targetable reentry warheads (MIRV). The warhead does not separate from the body of a Prithvi missile, which makes it a large target for both ground based radar and the radio frequency seeker to acquire and track. In the Pakistani M-9, M-11 (Chinese) and other Chinese missiles with ranges up to 2000 km the warhead separate from the missile body. According to Jane’s Strategic Weapons System, the warhead of the M-9 and M-11 separates either after burnout or before re-entry.

SUBSIDIARY RISKS

1) To derive the capacity to produce a desired effect more exo-atmospheric interception tests should be done to validate the overall performance of a decisive upper layer termination (PDV) which would proportionately reduce the burden on the lower tire (AAD).

2) Deployment of BMD system should not be done in haste as it would be wiser to deploy after this system is fully tested under various realistically simulated conditions such as inclement weather circumstances, protracted testing profile, automated classification, threat evaluation, prioritization and missile launch functions, clustered air environment (to discriminate actual target) and situational awareness to avoid friendly fire.

3) In the India-Pakistan context, the nuclear blackmail edge, which the latter advocates, will eventually erode as India has made the move to cleverly build a strategically credible redundant terminal defense system to provide effective protection for multiple target probabilities, however the risks still persists. As far as China-India strategic equation is concerned, an all out conventional war is predicted as a convention however, a resultant nuclear conflagration as a hypothesis cannot be ruled out which enforces the need to strengthen India's defense security because of China's qualitative (MIRV capability) and quantitative missile superiority.

CONCLUSION

Testing must account for the ever-changing ballistic missile threat scenarios and the latest technological developments. Ground and flight tests should provide data for highly advanced modeling and simulation activities that allows the scientists to measure and predict the performance of all missile defence technologies. Successful and foolproof flight tests in multiple simulated modes can impart greater confidence in the system’s capabilities. Because of the exorbitantly high costs, it would at best be able to provide protection to only a small number of its high-value politico-strategic assets, considered to be vital for the Nation’s survival. But, contrary to some critics, the very issue of national survival makes it mandatory for India to acquire BMD capabilities, given the policies of two nuclear armed irritants in our neighborhood.

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