posted on Feb, 1 2005 @ 01:13 AM
Indian defence scientists have embarked on an ambitious project to develop an active-radar homing (ARH) ASTRA, a beyond visual range (BVR) air-to-air
missile (AAM) capable of destroying enemy targets located at ranges up to 80 kilometres. The missile will be able to outturn a 9g target at that
distance, which means it should be able to engage a non-manoeuvring target in excess of 100 kilometres. The project will be guided and led by the
Hyderabad-based Defence Research and Development Laboratory (DRDL). ASTRA will weigh 150 kg, making it the lightest in its class and thus enjoying a
wide range of applications.
Interestingly some advanced countries and multinational corporations have indicated willingness to join hands for the ASTRA project and this should be
welcomed to ensure rapid development and Initial Operational Capability (IOC) with the Indian Air Force (IAF) and Indian Navy. In the long run the
ASTRA AAM is set to complement the ultra-long-range Ks-172 and long-range RVV-AE (AA-12 Adder) family of BVR AAMs and R-73RDM2 or possibly Python 5
NBVR/WVR (Near Beyond Visual Range/Within Visual Range) AAMs in the IAFs AAM inventory.
The emergence of top quality Phased Array radars in IAF service has made it possible to detect enemy fighter-sized targets at ranges well beyond 100
kilometres. Only high-quality stealth platforms will remain “invisible” at those ranges. The primary concern of the IAF and the ASTRA development
team will be of positive identification of enemy targets at those extended ranges. IFF (Identification Friend or Foe) still remains a challenging
complication and even while the United States Air Force (USAF) tactics are BVR dominated, very few BVR shots occurred in combat prior to Gulf War I
‘Desert Storm’.
During ‘Operation Desert Storm’ the United States Navy (USN) were disallowed the use of their AIM-54 Phoenix BVR AAMs for IFF at extended ranges,
because they lacked two-sources of information. USAF fighters did posses on-board systems to supplement data from Airborne Command Posts (ACP) like
E-3B 'Sentry' airborne warning and control system (AWACS) platforms and were allowed to conduct BVR engagements.
Thus since IFF remains a problem because of incorrect and absent returns and "spoofing", AWACS platforms are presently deployed for reconfirmation
of enemy airborne targets at extended ranges and in this respect the IAF will naturally be benefited by induction of PHALCON AWACS platforms. No more
the fighter pilots need to follow the risky "eyeball/shooter" sequence, where the flight leader comes unacceptably close to the enemy formation for
positive identification and passes the data to other fighters. His associates then fire the BVR missiles. In the long term, development of
electro-optical seeker technology coupled with on-board threat database will let the missiles themselves determine the legitimacy of the target and
this seems to be the logical option. This option should be considered for the ASTRA Project.
ASTRA should also have provisions for the futuristic concept of “Cooperative Fighter Operations” or Mixed Fighter Force Concept (MFFC) that is
essential for future BVR engagements and optimum performance and results. Pairs of aircraft need to be data-linked, allowing one to launch the
missiles against the targets while it is illuminated by another. In such engagements a fighter like our light combat aircraft (LCA) TEJAS, will be
able to impart the greatest kinetic energy to the ASTRA by accelerating up to Mach 2 and then manoeuvring out of the engagement. The illuminator
fighter such as the Sukhoi-30MKI with powerful radar capable of performing like a mini-AWACS would remain firmly subsonic keeping a decent distance
from the target, and providing either command-guidance updates or illuminating the target. The option for an Imaging Infra-Red (IIR) seeker for ASTRA
should remain open, as ARH is effective in one set of conditions and IIR in another. The open choice of different seeker heads also complicates the
problems of the adversary.
The propulsion system appears to be a Rocket/Ramjet because of “dimension and weight constraints”. Adopting a Rocket/Ramjet approach has certain
limitations. The need for controlled airflow to the ramjet ducts means that the “skid-to-turn” manoeuvring of a conventional rocket-powered
missile is not acceptable because it will risk masking an intake. Instead “bank-to-turn” manoeuvring needs to be adopted resulting in a reduced
instantaneous turn rate. Thus close cooperation with the European Consortium MBDA, the manufacturer of Meteor high-performance BVR AAM will prove to
be beneficial. The protracted delay in IOC of missiles like Trishul, Akash and Nag are partly because of absence of joint-cooperation with an
established foreign manufacturing consortium. This mistake should not be repeated during development of ASTRA especially as MBDA now enjoys very close
relationship with the Indian defence industries.
MBDA Meteor is capable of engaging air targets autonomously, whether fighters, bombers, transport aircraft, AWACS or cruise missiles by using its
active radar seeker by day or night and in all weather or dense EW (Electronic Warfare) environments. Meteor’s solid fuel variable-flow
rocket/ramjet propulsion system will ensure a range in excess of 100 km and a speed of more than Mach 4 and high terminal velocity. Even when launched
from extreme stand-off ranges, the missile will have the energy in the end game to defeat fast, manoeuvring targets. To ensure total target
destruction, the missile is equipped with both proximity and impact fuzes and a fragmentation warhead that is detonated at the optimum point to
maximise lethality. Guidance is ISN, two-way datalink and active Ku-band radar seeker. It can receive targeting data after launch from the launching
fighter, another fighter, or AWACS platforms. The two-way data-link partially solves the IFF problem at long ranges. Naturally inputs from the Meteor
project will benefit ASTRA development immensely. Also the control surfaces of ASTRA need to be folded for installation in internal missile bays of
fifth-generation fighters and for self-defence installations as Bomber Defence Missile (BDM) and in internal rotary-launchers of long-range Indian
Navy Tupolev-22M3 ‘Backfire-C’ aircraft.
The “primary carrier” of ASTRA BVR AAM is slated to be the indigenous LCA Tejas, which made its first flight on January 4, 2001. During the year
2001 LCA TD-1 made a total of twelve flights split between Wing Commander Rajiv Kothiyal and Wing Commander Raghunath Nambiar. Now along with two TD
(Technology Demonstrator) a PV (Prototype Vehicle) mor tests are also being conducting with more PVs to follow. The LCA is slated to attain IOC with
the IAF sometime during the year 2007. This can be termed as a remarkable achievement considering a relatively smoother transition from
“first-flight” to IOC. The Fly-By-Wire Flight Control System of the LCA has generated great international interest and LCAs low-speed handling and
low-altitude manoeuvrability at an early flight-testing stage points to emergence of a formidable fighter.
A recent visitor to our website had lamented the inordinate delay in IOC of the Tejas and it will be interesting to see how other such efforts had
fared worldwide. The dates of “first-flight” of few other four-plus or fifth generation fighters are given below:
Company
Aircraft
First Flight
Lockheed Martin/Boeing
F-22 Raptor
September 29, 1990
Dassault
Rafale
May 19, 1991
Eurofighter
Typhoon
March 29, 1994
Saab
Gripen
December 8, 1988
In each case there was a gap of nearly 10 years between the “first-flight” and IOC and so the progress of our LCA project is comparable. The aim
of Indian Defence Research scientists and the IAF should be to field a similarly upgraded LCA before 2010 with upgrades allotted to Swedish Gripen,
which is somewhat similar in size and configuration. These should include Active Electronically Scanned Array (AESA) radar and a formidable defensive
avionics suite, which detects the threats of not only incoming radar guided missiles, but also of missiles that use the infrared and ultra-violet
spectrum. Laser warning should also be an option. Add to all these a laser "device" capable of generating enough directed energy to snap the
guidance of incoming radar and infrared guided AAMs seem to be obligatory on all fighters by the middle of the next decade. It was reported in the
media that a 25 KW to 100 KW laser weapon was being developed for the projected United States F-35 JSF (Joint Strike Fighter).
Considering the fact that LCA is set to serve for a good part of the first half of this century, it should be a highly competitive design in terms of
aerodynamics, engine, radar, avionics, EW suite and weaponry in relation to the JSF. In terms of stealth attributes JSF will retain an advantage, but
LCA will also be low observable and even marginal superiority on other attributes may turn it into a great equalizer.
In some respects a delay in the LCA programme may be a “blessing in disguise” as now it derives or will derive the benefits of incorporation of
the technological excellence of Sukhoi-30MKI and the Russian fifth-generation fighter projects in future. Development in “Block Update Versions”
is now ensured.