Last Sunday morning’s canisterised launch of the Defence Research and Development Organisation (DRDO) developed Agni-V Intercontinental Ballistic Missile (ICBM) marks the arrival of India as a missile power. With a range of ‘easily more than 5,500 km’, one finds that India now has the ability to hold all of China’s Eastern Seaboard cities at risk from Peninsular India.
But again, there is more to this missile than its range capability. In technological terms, this missile represents the coming of age for India of a very long range payload delivery capability that is both rather accurate as well as survivable. It has a contemporary guidance package that utilises an indigenous ring laser gyroscope inertial navigation system (RLG-INS) coupled with a micro-inertial navigation system or MINGS.
Both the RLG-INS and MINGS are capable of receiving multi-constellation updates from satellite navigation systems such as the American GPS and the Russian GLONASS as well as India’s own IRNSS to remove accumulated errors in their measurements. However, IRNSS will not be able to provide coverage to the Agni-V over all of its trajectory, and foreign SATNAV systems cannot always be relied upon for targeting purposes as the signal itself may be switched off especially on the home stretch.
The superior accuracy of the Agni V can also be attributed to the incorporation of a system on chip (SOC) based on-board computer (OBC) that weighs just 200 grams and boasts 6-7 times greater processor capability than legacy PCB based systems. The embedded SOC concept requires very little power and gives far greater leeway in warhead configuration besides enhancing efficiency.
Agni-V is not just more accurate but is also more reliable and indeed survivable. While its 2.0-m-diameter, first stage motor is the same as that of the Agni III and made of 250 grade maraging steel, its second and third stages have carbon composite casings.
It thereby facilitates greater fuel fraction, enhancing range capability. In future, even the first stage of Agni-V will use carbon composite motor casings and that would take care of the issue of corrosion altogether and enhance overall structural integrity. The Agni-V also relies on digitally connected multi-channel communications within its body for the control system, thereby reducing a lot of the cabling that would have otherwise gone into such missiles. This serves to reduce the risk of failure in the missile system and increases dependability.
And this has been validated by Sunday’s launch, which was the fourth consecutive successful test of this missile. The use of corrosion-resistant composites and digital connectivity within the missile makes it easier in some sense to turn the Agni-V into a classic ‘wooden round’ – that is a canisterised missile system transportable by road and rail ready to launch on demand, with an almost maintenance free stowage and storage life of 10 years or so.
Cold launch scheme
Agni-V in canisterised configuration consists of a mission ready missile, a gas generator for ejecting the missile out of the canister to a height of about 30 metres at which point the Stage-I motor ignites, and the canister itself that provides protection besides serving as a cold-launch tube. This cold launch scheme allows the missile to be launched from relatively unprepared strips.
The missile canister sits on the Agni-V’s Transport-cum-Tilting vehicle-5 (TCT-5), designed and developed by DRDO’s Vehicle Research and Development Establishment, Ahmednagar. The Agni-V itself is 17 metres long and has a launch weight of about 50 tonnes with a 1.5 tonne payload which is adequate to carry fusion boosted fission warheads with a yield of 200-300 kilotonnes.
Now, while an Agni-V locked and loaded sitting in a canister somewhere in India is not exactly what China likes to hear first thing in the morning, the middle kingdom could actually have more to worry about. The Agni-V's re-entry vehicle shown in previously released pictures may turn out to be rather manoeuvrable making things difficult for emerging Chinese terminal anti-ballistic missile (ABM) defences. Incidentally, the third stage of the Agni-V is a conical motor which allows greater acceleration in flight and makes it more difficult for mid-course interceptors to tackle it as well.
All three stages of the Agni-V in any case have flex nozzle control systems which enhance manoeuvrability during flight. Two more ‘user assisted trials’ by the Strategic Forces Command will be done before the Agni-V is considered deployable. It may also serve as a baseline for a longer ranged and heavier missile that will carry multiple independently targetable re-entry vehicles (MIRV) and this missile may be designated Agni-VI. Despite, the Agni-V’s current potency, a MIRV Agni-VI will be needed to guarantee penetration against China’s ABM system in the decades ahead.
(The writer is a New Delhi-based commentator on security and energy issues)