India’s indigenous BVRAAM
Evolution of the Astra
Self-reliance in air launched missiles, particularly Beyond Visual Range Air-to-Air Missile (BVRAAM) systems is of strategic importance considering the new paradigm of air superiority warfare. With the service entry of an indigenous hypersonic (Mach 4 plus) Active-Radar Homing (ARH) Astra BVRAAM, India’s Defence Research and Development Organisation (DRDO) seems to have produced a missile that is arguably capable of matching – or outmatching – similar class of missiles of United States, Russian and European origin.
As part of its development, this missile was first tested on 18 March 2015, launched from an Indian Air Force Su-30MKI fighter against a simulated live target to verify the control system and missile stability during flight. Prototype of the missile was first tested on 9 May 2003 from the Integrated Test Range (ITR) at Chandipur-on-Sea off the Odisha coast. On 27 March 2007, vertical launch of the missile was carried out, suggesting possible development of a Surface-to-Air Missile (SAM) variant as well. Following further tests, dual-mode guidance was proved during May 2009 followed by captive flight tests on a Sukhoi
Su-30MKI, carried out from Pune in November 2019 when several sorties were conducted. The series of numerous tests initiated on 20 May 2011, also from the ITR at Chandipur focussed on evaluating performance of the smokeless nonmetallised high specific impulse propulsion system, rocket motor, and configurations of the vehicle. Aero-dynamic evaluation with the missile incorporating significant changes and incorporating advanced technologies was also done in due course.
The project is led by the Hyderabadbased Defence Research and Development Laboratory (DRDL). The single stage, smokeless, solid fuelled Astra with a length
of 3570 mm, body diameter of 178 mm weighs 154 kg, is powered by high energy lithium thermal batteries, making it the lightest in its class and thus having a wide range of applications. The BVRAAM will be capable of destroying 9g manoeuvring enemy targets at high altitude in the head-on mode at a range of 80 km and in tail-chase mode at 20km, thanks to its redesigned cropped delta (replacing low drag low aspect ratio) wings and capability to pull a lateral acceleration of 40g in both yaw and pitch planes which means it should be able to engage non-manoeuvring targets well in excess of 100km and capable of operating in the altitude bracket from sea level to 20km.
The all-important seeker was initially provided by Russian’s Agat (possibly more advanced than 9B-1348E integrated on R-77 variants) with an autonomous homing range of 25km plus, which enables offbore sight launches up to an angle of 45 degrees and produced in India through a transfer-of-technology process. Prior ARH homing during terminal stage, Astra follows Fibre Optic Gyro (FOG)-based Inertial Navigation System (INS) during midcourse with high g accelerometers along with secure data link to allow midcourse re-tasking. While autopilot and guidance software uses Artificial Intelligence (AI) for accurate guidance and optimised trajectory, the on-board Electronic Counter Counter Measures (ECCM) capability allows it to stay on course in spite of enemy Electronic Counter Measures (ECM) procedures.
The 15kg high explosive warhead is pre-fragmented and radar proximity fuse armed plus directional to enhance lethality and Single Shot Kill Probability (SSKP). Additionally, the DRDO is currently working on a new laser fuse. The choice of an Agat seeker is interesting as this establishment is highly reputed for development of infra-red seekers and indicative of an Imaging Infra-Red (IIR) version of the Astra. As ARH is effective in one set of conditions and IIR in another, the open choice of different seeker heads complicates situation of the adversary.
In continuing development, on 15 September 2017 an Astra BVRAAM was test fired from a Su-30MKI from Kalaikunda Air Force Station with an indigenous Kuband pulse Doppler radar seeker developed by Research Centre Imarat (RCI). With an antenna diameter of 140 mm and weight of 12.5kg, the lock on range is well in excess of 12km and gimbal angles of plus/minus 55 degrees. The same indigenous seeker is also set to arm the Akash-1S Surface-to-Air Missile (SAM) variant and also the QRSAM, with final development trials completed the same month. During user trials in 2019, the Astra BVRAAM decimated a manoeuvring target at a distance of 90km.
Projected to be a game changer at the tactical level, Astra BVRAAMs are reportedly to be integrated with all frontline Indian Air Force fighter aircraft including the Sukhoi Su-30MKI, MiG-29, Mirage 2000 and the indigenously developed
Tejas LCA, and can be launched both in autonomous and buddy-mode operation. Reportedly, the Mk.2 version of Astra will have a maximum range in excess of 150km and tail chase range of up to 35km propelled by a dual-pulse rocket motor similar to the AIM-120D AMRAAM.
The DRDO is also looking at rocket/ ramjet propulsion to provide greater range and enhanced kinematics performance to the BVRAAM. However adopting a rocket/ ramjet approach has certain limitations as the need for controlled airflow to the ramjet ducts means that the ‘skid-to-turn’ manoeuvring of a conventional rocketpowered missile is not acceptable (because it will risk masking an intake) yet ‘bankto-turn’ manoeuvring results in a reduced instantaneous turn rate.
Even more ambitious, the Astra Mk.3 is projected to be a Solid Fuel Ducted Ramjet (SFDR) powered missile with ranges in excess of 300 km. Under such circumstances, the primary concern of the IAF and the Astra development team will be of positive identification of enemy targets at those extended ranges since Identification Friend or Foe (IFF) remains a problem because of incorrect or absent returns and ‘spoofing’. Hopefully in the long term, development of electro-optical seeker technology coupled with on-board threat database will let the missiles themselves determine legitimacy of the target!