It is not unusual to see news of a Pakistani ballistic missile launch close on the heels of an Indian ballistic missile event. The launch of Agni 5 took place on 26 December last year followed by the launch of Agni 4 a week later. For the Pakistani missile establishment, the year 2016 was a comparatively quiet year and one did expect a response to the Agni launches. Sure enough, Pakistan carried out a missile test – it was not another training or pre-deployment test of Shaheen 2 or Shaheen 3, but the test of a new missile called Ababeel on 24 January 2017. The missile is claimed to have a range of 2200 km and is said to be capable of carrying Multiple Independently Targetable Re-entry Vehicles (MIRV).
Unlike the Shaheen 2, the new missile has three stages. The Ababeel thermal fairing (heat shield) has a larger diameter than its core vehicle. The extra volume thus available is consistent with the requirements for MIRV capabilities. It must however, be noted that there are a number of technical constraints that have to be overcome before one can infer that Pakistan has succeeded in developing MIRV capability.
MIRV, as the name implies replaces a unitary warhead with a larger number of smaller warheads, with each of them programmed for different targets. It is therefore a more potent and powerful attack system. In a global scenario where a number of countries are developing Ballistic Missile Defence (BMD) Systems, MIRV capability is needed to overwhelm such defences. Many BMD systems have capability limitations when it comes to dealing with multiple incoming warheads and may fail to engage all of them. By increasing the number of warheads along with decoys deployed with the real ones, BMD systems can be saturated. The US and Russia field such MIRV weapon systems and the numbers they field are governed by the strategic arms limitation treaty between them. The Chinese are also said to have incorporated MIRV in their DF 5, DF-31 and the JL 2 (the submarine launched version of the DF-31) ballistic missiles.
Over the last several years India has carried out a number of tests related to terminal phase BMD. These involve the interception of the warhead outside the atmosphere just before the re-entry of the incoming missile. For a country confronted with such an adversary, developing MIRV capability is the logical technology growth route to follow. One is therefore not surprised if Pakistan were to adopt such a route.
The rhetoric in the Pakistani establishment against Indian ABM capability is indicative of this. Sartaj Aziz, Pakistan’s advisor on Foreign Affairs is reported to have commented in June last year that India’s testing of anti ballistic missile system could lead to ‘unexpected complications’. He is further stated to have told the Pakistani senate that Pakistan has serious concerns over these developments and will take ‘all necessary measures to augment its defence capabilities’.
Has Pakistan really overcome the technological challenges?
Though it is easy to express a need for the development of MIRV capabilities realizing it requires significant advances in a number of key technologies. The question to ask before we come to any conclusion is ‘Has Pakistan been able to master and overcome all the technical issues?’ In this regard, a critical assessment of the following issues is particularly necessary.
- Weapon miniaturization: For MIRV requirements both the warhead and the re-entry vehicle (RV) need to be smaller and lighter. The US Minuteman-3 missile warhead had three Mk-12A RVs. The RVs had a base diameter of about 0.5 metre (m) and a length of approximately 1.81 m. Three such RVs could be accommodated within the missile shroud, which had a diameter of approximately 1 m.
- Ababeel has a bulbous fairing at the top with a diameter estimated to be 1.7 m in which it may be physically possible to house three to four MIRVs of the Mk-12A type. The warhead fitting into this RV must have dimensions lower than that of the 0.5 m diameter. Has Pakistan managed such a miniature design and if so, how reliable is it?
- The tests carried out by Pakistan on 28 and 30 May 1998 were all based on highly enriched uranium. Pakistan till-date not carried out any plutonium based weapon tests. The Plutonium route for warhead design is needed for developing smaller warheads required for MIRV. Without testing such a device the design confidence, performance repeatability, as well as system reliability is likely to be low. This raises the question of credibility behind Pakistan’s claims of MIRV developments.
- A major requirement for a MIRV system will be the Post-Boost Control Vehicle (PBCV). The MIRV’s need to be supported on top of the PBCV, which houses a bank of liquid thrusters for 3-axis stabilization and for providing the axial thrust needed for maneuvers. In addition, each MIRV has to be positioned and released at different times during the trajectory based on the various targets that need to be reached. The MIRVs also act as a thermal protection system for their miniature warheads and protects them from the heat generated during reentry into the atmosphere.
- The PBCV is essentially a missile stage housing liquid propellant tanks, pressurization tanks and banks of thrusters with intricate plumbing. Though Pakistan has exposure to liquid propulsion technology through the Ghauri missile, the same cannot directly be applied to PBCV. PBCV related developments require expertise in design and fabrication of small thrusters, fabrication of propellant and gas tanks, precision fabrication of valves, high-pressure plumbing, quality control and storable liquid propellants.
From media reports, it would appear that Pakistan has been working on liquid propulsion systems for use on missiles. The coverage of the successful launch of Shaheen-1A in the Dawn Newspaper of 25 April 2012 included a statement that suggested the missile possessed a ‘post-separation attitude control system’. The post-separation attitude control system (PSAC) is essentially a liquid propulsion package used for providing thrust in the axial direction as well as for stabilizing the RV. RV of Shaheen-2 by extension would incorporate this system. Shaheen-3 flight-tested twice in 2015 is said to have a range of 2750 km. The additional range seems to have been achieved by combining in the PSAC the functions of a third stage as well as stabilization. System engineering from this to a PBCV therefore seems doable.
As argued above, the technical feasibility of a liquid propulsion package is possible, but the possibility of external help either from China or North Korea cannot be ruled out. The fact that design-engineering, testing, qualification and incorporation in three missile systems has been achieved in record time is also indicative of external support including material, component and sub-system supply.
- The Notice to Mariners issued by the Pakistan Navy earmarks the missile flight range safety zone and in this case the farthest points of the safety zone are located at 1100 km from the launch range at Winder and far short of the claimed range of 2200 km. This could mean that the Ababeel flight of 24 January was a proving test of a new missile system. The lower range was the result of achieved design parameters (e.g. higher inert mass, lower propellant energetics) or by trajectory shaping. One usually expects to test a missile to its the full potential on the first developmental flight and not for a shorter range.
In summary, it would appear that Pakistan is in the process of putting together the building blocks for a MIRV capable missile. However, their assertion of possessing miniaturized warheads is open to doubt. The Chinese transfer of the CHIC-4 nuclear weapon design to Pakistan , which even involved orchestrating a test of the system for Pakistan in 1990, is well documented. According to Thomas Reed, co-author of the book ‘The Nuclear Express – A Political History of the Bomb and Its Proliferation’, the speedy response by Pakistan to the Indian nuclear tests of May 1998 was on account of the fact that they had a ‘carefully engineered device in which they had great confidence’. This confidence emanated from the receipt of the CHIC-4 design, training received by them and the test carried out by China for Pakistan in 1990. China’s interests today are economic; China is close to achieving big power status; and has no major stake in furthering Pakistani nuclear weapon capability. Pakistan may therefore have to depend upon itself for achieving the required miniaturization of weapon systems for use in MIRVs.
The US has built and tested a large number and variety of weapon systems. Consequently, when they undertake a re-design or reliability upgrade programme, they have reams of test data to back their design effort. In spite of this they have had number of problems and many issues related to safety. The description of accidents during carriage and other near-miss situations that US nuclear weapons have been involved in is lucidly described in the book ‘Command and Control’ authored by Eric Schlosser. Seen in this light, the reliability of an untested weapon system is open to question.
While one can question whether the recent Ababeel can deliver on all the claims made by Pakistan there is no doubt that Pakistan will move towards maneuverable and MIRV missiles to counter Indian BMD systems. From an Indian perspective, it is necessary to continuously monitor and assess the evolution of Pakistan’s capabilities and the connections these capabilities have with Pakistan’s war-making and deterrence strategies. This will ensure that Indian responses are measured, responsible and aligned with Pakistan’s true capabilities.
Missiles from Pakistan, irrespective of the type of warheads they carry pose a problem for India. Their very short flight times make it imperative that India develop systems for the early detection of missile launches for activating Indian countermeasures.. India will need to supplement its ground-based detection with space-based detection systems to better manage shortcomings in early warning capabilities.
Rajaram Nagappa is Professor and Dean of the International Strategic and Security Studies Programme, National Institute of Advanced Studies, Bengaluru. A noted expert on missile technology, Prof. Nagappa has specialized in aerospace propulsion and has worked extensively in the design and development of solid propellant rockets. He has made major research contributions to the analysis of Pakistani ballistic missile production capability. His recent work includes an assessment of Pakistani cruise missiles and an assessment of the Iranian satellite launch vehicle Safir.
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