New Delhi, 28
November 2003
Prasun
K Sengupta is a defence analyst based in Malasia who writes
regularly in TEMPUS magazine. His detailed analysis for a viable
ballistic missile defence (BMD) system for India, to counter the
threat of attack by WMDs, is both relevant and thought provoking. As
always the author's views are his own and we do not necessarily
subscribe to them. Comments on the article through our Feedback page
or by email to idc@ispone.net
are more than welcome.
Which
Way Is India’s BMD/AEW System Headed?
By
Prasun K. Sengupta
How
does one conceptualise an India-specific ballistic missile defence (BMD)
system? According to senior officials of the Indian Army’s
Directorate of Field Artillery and the Indian Air Force’s
Directorate of Offensive Air Operations (these two Directorates have
now become integral ‘operational’ components of India’s
Strategic Forces Command), this is how things are envisaged: Since
there is no way to distinguish between the types of warheads of
attacking tactical/theatre ballistic missiles (TBM), it is
impossible to know if an incoming warhead is nuclear, chemical,
biological or conventional. Consequently, from the moment a country
such as Pakistan possesses nuclear, chemical or biological warhead
delivery capabilities with TBMs, India will be forced to assume that
the TBMs aimed at its territory are carrying warheads of mass
destruction (WMD), and will have to respond accordingly.
In
such an environment of ‘mutually assured destruction’ in South
Asia, there will be a need for an immediate lethal response, in
order to preserve the credibility of an Indian second nuclear
strike. In all cases, India will have to absorb a lethal blow,
because of its geographical and demographic characteristics.
However, a deadly riposte by India will not save it. It will only
inflict a deadly blow on the aggressor, so that both sides will be
hit, but the targeted Indian sites will still be wiped out.
Therefore,
in the centre of Indian strategic thinking lies the obligation to
neutralize the risk of a WMD first-strike initiated by the
belligerent, be it Pakistan or anyone else. If India succeeds in
doing so and at the same time possesses the potential of destroying
the enemy, the enemy’s motivation to destroy India by using WMDs
will be eliminated. The planned India-specific BMD system, which is
designed to eliminate the danger of a first strike with WMD-equipped
TBMs, is intended to achieve this aim and provide India with a
‘Strategic Depth of Time’, which would allow the Government of
India to act, free of apocalyptic threats.
This
then brings us to defining the operational and qualitative
requirements of an India-specific BMD system. In order for such a
system to be able to meet the expectations described above, it must
be capable of intercepting a salvo of TBMs attacking from distances
of up to 1,500km away, and do this with a maximum leakage rate of
one in a thousand, or 0.1%. There is no BMD system existing today
that can guarantee an interception probability of 99.9% (which is
equivalent to a leakage rate of 0.1%). However, it is possible to
achieve an interception probability of 90%.
The
transition from 90% to 99.9% can, however, be performed by using a
multi-tiered approach, and by incorporating into the BMD system’s
guided-interceptor missile and its fire-control radar (FCR) the
attributes that support such a multi-tier operation. The
multi-tiered approach can be implemented by providing a minimum of
three independent discrete opportunities of interception. The first
opportunity is in the first layer at the highest altitude possible.
In this case the FCR will monitor the results of the encounter with
a single interceptor missile and provide the optimum kill
assessment. If there are no kills, two additional interceptor
missiles will be launched at short time intervals. These constitute
the second and third layers. Using this technique, three independent
interception possibilities can be provided, which raise the
interception probability of an incoming TBM from 90% to 99.9%, thus
satisfying the leakage rate requirement.
Indian
defence planners (civilian and military) involved in developing an
India-specific BMD network estimate that the capability of existing
TBMs currently operated by countries like Pakistan will not exceed a
total salvo of 50 TBMs armed with WMD warheads during the next 10
years. On the assumption that India will have to counter an attack
on a scale totalling 50 WMD-equipped TBMs, there will be a need for
60 interceptor missiles (the 1.2 ratio mentioned earlier). With an
additional assumption that there will be a need to guarantee the
overall defence of India in three distinct theatres (the Indo-Gangetic
plain, western India and south-western India), the overall number of
interceptor missiles required will reach 180. To this number, a
technical reserve of one third has to be added, so that the final
number is 240 interceptor missiles for a functional and effective
India-specific BMD network.
In
order to achieve the deterrent effect based on an active defence
strategy which finds expression in the capability of an
India-specific BMD system, India needs to publicly declare that any
attack made against her by ballistic missiles will be interpreted as
an attack using nuclear, chemical or biological warheads, with the
intention of annihilating India. To this end, an India-specific BMD
network must be seen as an extension of India’s ‘no first-strike
with WMD’ policy. Thus, a White Paper on India’s proposed BMD
system is long-overdue and needs to be tabled by the Government of
India without any further delay.
As
far as R & D efforts undertaken thus far by the state-owned
Defence Research & Development Organisation (DRDO) to develop an
India-specific BMD system are concerned, the only credible step
undertaken so far has been the acquisition of two EL/M-2080 ‘Green Pine’ radar systems from Israel Aircraft Industries (IAI).
Ordered in 1998, both the radars were delivered in 2001. The Green
Pine is an L-band active phased-array search, acquisition and FCR
all rolled into one, which can
detect and track incoming TBMs as far way as 500km and can guide the
Arrow 2 hypersonic interceptor
missiles within an engagement envelope of 16km and 48km.
The complete radar system comprises the trailer-mounted radar
and antenna array, power generator, cooling system, and a radar
control centre. It
is similar in concept to the Raytheon-built Theatre High
Altitude
Air Defence (THAAD) radar, which is an X-band, active phased-array,
solid-state radar system. Based on operational inputs from the
Indian Air Force (IAF), the DRDO has been tasked with developing a
complete integrated BMD system, including missile launchers,
missiles, multi-purpose radar, computers, and associated battle
management command-and-control elements, all of which are required
to work in concert to detect, identify, assign, and destroy incoming
TBMs.
Clearly,
based on the operational requirements and the available
military-industrial infrastructure available within India, it is
obvious that a ‘domestic/indigenous’ deployable solution is out
of the question in the foreseeable future. The DRDO’s Akash
surface-to-air missile (SAM) and its associated ‘Rajendra
Battery-level active phased-array FCR, the 3-D Central Acquisition
Radar (CAR), and associated engagement control centres, which have
been frequently touted by many as one with potential BMD
capabilities, is at best a SAM system capable of engaging hostile
airborne combat aircraft and air-breathing/subsonic land attack
cruise missiles, provided the Rajendra and CAR systems are
supplemented by an integrated network of ground-based passive
optronic search-and-track systems. Here too, the necessary core
technological competencies have yet to be attained by the DRDO.
Originally
conceived as a SAM to counter manned, manoeuvring airborne
platforms, the medium-range Akash, which was first test-fired in
1990, underwent developmental test-flights till March 1997.
Operational tests and evaluations are still continuing. The
27kg-range missile, armed with a 60kg blast-fragmentation warhead
with an effective radius of 20 metres, uses an integral ramjet
rocket propulsion system to give a low-volume, low-weight (700kg
launch weight) missile configuration, and has a reaction time (from
detection to missile launch) of 15 seconds. The SAM’s
solid-propellant booster accelerates it within 4.5 seconds to Mach
1.5, and is then jettisoned. The ramjet motor is next ignited for 30
seconds to propel the SAM to a top cruising speed of Mach 3.5 at 20g
and up to a service ceiling of 15km. The SAM is equipped with four
long, tube-ramjet inlet ducts mounted mid-body between four clipped
triangular moving wings for pitch/yaw control. Forward of the tail
are four inline clipped-delta fins with ailerons for roll control.
All flight control surfaces are operated by pneumatic actuators. The
fuse is of the Doppler radar proximity/contact type. The missile has
tail-mounted G/H-Band transceivers to assist its tracking by the
Rajendra multi-purpose FCR. Boost-phase guidance is inertial, with
mid-course correction updates coming from the Rajendra using the
track-via-missile guidance technique, with an on-board semi-active
radar taking over for the terminal phase (the final 3-4 seconds).
The
Rajendra FCR, being developed by the DRDO’s Hyderabad-based
Electronic Research & Development Establishment (LRDE), comes
mounted on a modified BMP-2 tracked armoured infantry fighting
vehicle chassis, like that of the Akash SAM launcher. Rajendra,
whose early warning antenna array contains 2,000 ferrite phase
shifters (operating in the G/H-Band or 4-8GHz), can track 64
airborne combat aircraft at medium-altitude out to a range of 60km
in the sector-scan mode. The radar’s engagement antenna array with
1,000 phase shifters operating in the I/J-Band (8-20 GHz), and a
16-element IFF array, can engage four airborne targets
simultaneously with 12 SAMs. A typical Akash SAM Battery will
comprise three SAM launch vehicles (each containing one triple-round
swivelling launcher on a modified BMP-2 chassis), a Rajendra FCR
vehicle, a TATRA 8 x 8 vehicle mounting the 3-D CAR, and an armoured
command vehicle, also mounted on a TATRA 8 x 8.
Consequently,
the only viable and ‘proven’ solution, and one preferred by the
IAF, is the ‘Homa’ (Fence) system developed by IAI’s MLM
Division, which has been operational since 2000. The entire system
comprises the Green Pine radar, Citron Tree battle management centre
(built by Tadiran), 1.3-tonne Arrow-2 interceptor missile, and
Tadiran’s containerised ‘Hazelnut Tree’ launch control centre.
The Homa system is designed to simultaneously intercept as many as
14 incoming TBMs. Citron Tree, which is trailer-mounted, downloads
data from Green Pine along with data from other sources (like
long-endurance unmanned aerial vehicles such as the IAI-built HERON
and manned airborne early warning & control platforms like the
PHALCON, both of which India is acquiring), using powerful signal
processing tools to manage the interceptions automatically,
including against single and multiple threats. The Citron Tree has
workstations for the Sky Situation Coordinator, Intelligence
Officer, Post-Mission Analysis Officer, Resource Officer and Senior
Engagement Officer, as well as the Commander’s workstation. The
workstations display a large electronic map showing the area of
battle. Predicted and confirmed launch sites are colour-coded to
show priority sites. When a TBM launch is detected, its launch site,
the TBM’s position and trajectory, and the predicted impact point
are displayed on the electronic map. The predicted impact point is
displayed as an ellipse on the map. The size of the impact ellipse
shrinks as the TBM’s trajectory stabilises and the trajectory data
becomes available. The trajectory image is colour-matched to the
image of its launch site. The optimum intercept point is also
displayed.
The
two-stage Arrow-2 interceptor missile, equipped with
solid-propellant booster and sustainer rocket motors, uses an
initial burn to carry out a vertical hot launch from the container,
and a secondary burn to sustain the missile’s trajectory towards
the target at a maximum speed of Mach 9, or 2.5km/second.
Thrust-vector-control is used in the boost and sustainer phases of
flight. At the ignition of the second stage sustainer motor, the
first stage assembly separates. The Arrow-2 is launched before the
hostile TBM’s trajectory and intercept point are accurately known.
As more trajectory data becomes available, the optimum intercept
point is more precisely defined and the Arrow-2 is guided towards
the optimum intercept point. The kill vehicle section of the
Arrow-2, containing the RAFAEL-built high-explosive, directed
blast-fragmentation warhead, fusing and terminal dual-mode seeker
(incorporating a Raytheon-built passive infra-red sensor containing
an indium antimonide focal plane array for the acquisition and
tracking of TBMs, and an active radar seeker used to home on to
air-breathing targets like land attack cruise missiles at low
altitudes), is equipped with four aerodynamically-controlled moving
fins to give low-altitude interception capability. The warhead is
capable of destroying a target within a 50-metre radius.
As can be seen
from the above-mentioned data, essential elements of a functional
‘Homa’ derivative specific to India are already in place, i.e.
the Green Pine and HERON, with up to six PHALCON AEW & C
platforms to be delivered by IAI to the IAF between 2006 and 2010.
Financial and operational prudence therefore demands that the
remaining elements of ‘Homa’ be acquired and deployed in the
near future by India’s Strategic Forces Command. The only
‘indigenous’ mission-critical inputs required to make an
India-specific ‘Homa’ BMD system with truly Indian
characteristics are in the areas of network-centric data fusion and
aerospace battle management solutions--areas in which the DRDO and
India’s private-sector Information and Communications Technology (ICT)
corporate entities already have considerable core technological
competencies.
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