The Indian move towards MIRVs
India's pursuit of multiple independently targetable re-entry vehicle (MIRV) technology has been variously described as being in the design or technology development phase in recent times. This position was reiterated on the side lines of the second successful test of the Agni V Intercontinental Ballistic Missile (ICBM) last September by officials from DRDO. Of course there had been some confusion in the past as to whether it is the Agni-V itself which will have a MIRVed variant or whether the first Indian MIRV configuration will be exhibited by a new vehicle sometimes referred to as the Agni-VI in the media. Nevertheless, repeated references to India's program for MIRVs has raised the heckles of the usual quarters in the Western hemisphere who either see it as destabilizing or a departure from India's stated nuclear doctrine of credible minimum deterrence(MCD). But truth be told MIRVs are a strategic priority for India precisely because of its deterrence philosophy and the emergence of anti-ballistic missile (ABM) systems in China and elsewhere.
The second test of the Agni-V served to underline the repeatability of a number of new components that contribute towards increasing the payload fraction of Indian missiles (significant for MIRVing) as well as their reliability and robustness. The Agni-V boasts contemporary technology such as wholly carbon composite second and third stages on the materials side and system on chip (SOC) and digitally connected multi-channel communications on the avionics side. Composite stages have greater structural integrity than metallic stages and weigh less for similar size. They are also more corrosion resistant. SOC eliminates the need for PCB based hardware for on-board computers that weigh up to 5 kgs in legacy missiles. SOC based computers weigh just 200 grams and boast 6-7 times higher processor capability while requiring very little power and giving far greater leeway in terms of warhead configuration. SOC's therefore also aid the process of designing MIRVed missiles. Digitally connected multi-channel communications for the control system of missile of course get rid of the miles of cabling that would have otherwise gone into these missiles.
These developments taken together therefore sit very well with the desired aim of deploying the Agni-V in a canisterized configuration. Canisterization requires that a high degree of confidence be held in the dependability of the missile's components so as to make it a 'wooden round' i.e once deployed the missile moves in the canister itself carried by a truck (or even train as in the case of the Russian SS-24 Scalpel) ready to be launched on warning. It also requires shaving of as much missile
weight as possible for improved or comparable mobility to an equivalent non-canisterized road mobile system since the canister's weight also counts, naturally. Given India's second strike posture which puts a premium on survivability, canisterization has become an imperative for the land based missile leg of India's nuclear deterrent.
While India's Strategic Forces Command (SFC) already has rail mobile Agni-IIs and IIIs deployed, it has been deemed that a better cost benefit calculus is possible by making India's newer long range ballistic missiles canisterized road mobile systems. Indeed the next test of the Agni-V, likely to be conducted soon, will be from a canister and the Agni-IV is also likely to be canisterized in the future. But the transporter erector launchers (TELs) deploying these missiles differ from the Russian MAZ series vehicles. While road mobile TEL's deployed by Russia are designed for cross country mobility in that country's vast forested hinterlands and for quick exits from their shelters in case of garrison basing, India's road mobile missiles will be randomly based across India's road network consisting of everything from a highway to perhaps even a Class II road.
The idea is to deploy camouflaged TEL's that would look like every day semi-trailer trucks at least when viewed from above. Thus concealment in addition to road mobility is a cornerstone of India's future land based missile force. As Avinash Chander then Chief Controller Missiles and Strategic Systems, DRDO (and now Director General, DRDO) put it in an interview to Frontline in April 2012.
You can stop on the roadside on the highway, launch from there and go away. You can stop the traffic for five minutes on either side, launch and go away. Your ability to move, your options to launch and your operational flexibility increase manifold. You have a reduced reaction time. Everything is already prepared. Just make the missile vertical in three minutes, and the launching takes another few minutes. So you stop, launch and go off. That does not give the enemy a chance even if he detects you. He does not know from where you are going to launch. Only when you have made the missile vertical for launch will he realise that you are going to launch it. The boost-phase destruction that people are talking of, that is, the missile getting destroyed before it takes off, will not be possible if you have a short reaction time as in a canisterised launch unless you have a space-based radar weapons system. Today, it is non-existent and is not likely to be developed in the next couple of decades at least.
Given that this is the intended pattern for deployment, it is understandable that the actual number of such vehicles transiting India's road network will be kept modest, to ensure water tight protection and manageability. Indeed the greater threat to such systems probably comes from clandestine ground level operations rather than from a targeted first strike. Accordingly an enemy would perceive much lesser gains from a first strike against such systems in MIRV configuration then it would if the same missiles carrying MIRVs were deployed in hardened or even super-hardened silos.
While MIRVed missiles sitting in silos do greatly increase the temptation on the part of the enemy to risk a first strike it is debatable whether the same can be said for randomly based camouflaged mobile missiles carrying MIRVs which even an enemy with very good C4ISR technology will find difficult to locate in time amongst India's clutter. Again, given the need to keep India's land based deployment pattern manageable, the number of missiles themselves will be kept modest and this ties in well with the need to have an affordable nuclear deterrent.
On the other hand limited numbers actually strengthens the case for MIRVing. Since India has opted for stealth rather than sheer numbers for its land based missile force (i.e in terms of boost vehicles), increasing the targeting capability of these missiles is a need and that is precisely where MIRVs prove useful. India's counter-value doctrine requires that its forces survive an enemy first strike and retaliate massively. It is therefore important that whatever percentage of India's modest sized deployed missile force survives an enemy first strike, is able to inflict unacceptable damage in the enemy's perception.
It is here that MIRVs emerge as particularly useful since each MIRV could be used to attack a spread of targets within a certain 'footprint' area. From India's perspective China's urban conurbations at the mouth of its historically settled rivers provide an ideal target for MIRVed missiles. Even a few Agni series missiles carrying 3-5 thermonuclear MIRVs each would be sufficient to put paid to the 'Chinese miracle'.
Now there has been a fair bit of confusion about whether an Agni V variant itself will feature a post boost control vehicle (PBV) on top of its three stages which would allow it to position and deploy MIRVs or a new three-stage ICBM of the Agni series will sport a PBV. This confusion however could also serve to underline that not all of India's modest road mobile force will sport MIRVs and that means that the overall number of warheads deployed by India's land based missile force will also remain modest.
Similarly, India is likely to maintain one or two SSBNs (with about 12 missile tubes on the Arihant follow ons) on constant deterrent patrol in the future and even if all the missiles they carry are MIRVed the total number of warheads at sea won't be that many (assuming 3-5 warheads per missile at the most). So MIRVing doesn't really challenge the 'minimum' part of India's deterrent strategy at all when seen in the appropriate context and away from deliberate alarmism.
It does however bolster the 'credible' part of India's doctrine in an environment where China is moving ahead with mid-course ABM technology. One should note China's first mid-course interception test took place in 2010 prior to the Agni-V being tested for the first time in 2012. As Avinash Chander told this writer in an interview earlier this year, "MIRVs give you a higher leakage probability."
India therefore has the two rationales for deploying MIRVs, increasing targeting ability with a modest number of missiles and easier penetration of ABM systems. Indeed, while treaty limitations initially forced the cold war superpowers to put more warheads on their existing missiles to ensure counterforce potency, India's self-imposed limitations require the same for counter-value targeting against China which is moving ahead on ABMs. In the future, India's MIRVs will also be manoeuvring re-entry vehicles (MARVs) clearly underlining that SFC will ensure that enough deliverable warheads can survive any potential enemy first strike and that these warheads are indeed delivered to their targets.
Saurav Jha's Blog : The Indian move towards MIRVs