India and Indonesia on Tuesday reached a significant milestone in their growing strategic cooperation by signing a deal for the supply of the ASTRA Mk 1 ‘beyond-visual-range air-to-air missiles’ (BVRAAM).The development is significant as it marks India’s first export of ASTRA missiles to another country. These missiles will arm Indonesia’s Su-30 fleet. The deal came alongside other key agreements — including the sale of BrahMos supersonic cruise missiles, major defence technology transfers, critical mineral extraction and maritime security. Developed by the Defence Research and Development Organisation (DRDO), ASTRA is a family of indigenous BVRAAMs that will be integrated with the Air Force and the Navy.Beyond-visual-range (BVR) missiles are those capable of engaging beyond the range of 20 nautical miles, or 37 km. Air-to-air missiles are primarily fired from an airborne asset to destroy an airborne target.We explain the features of the ASTRA missiles and their strategic importance.The missile and its variantsThe first in the family, ASTRA Mk 1, has a range of 80 to 110 km, an altitude of up to 20 km and a speed of Mach 4.5 (or 4.5 times the speed of sound). The key features of this missile include inertial guidance, mid-course update and terminal active radar homing.Story continues below this adThe missile is being integrated with the IAF’s Sukhoi-30 MKI fleet and is also planned to be integrated with the indigenous Light Combat Aircraft Tejas Mk 1 A and the French Rafale jets in future.Last year, DRDO and the IAF successfully conducted the flight test of ASTRA Mk1 equipped with an indigenous radio frequency (RF) seeker from a Su-30 MKI jet.A more advanced version of the ASTRA Mk 1 — the ASTRA Mk 2 — has an enhanced range of 200 km, from the earlier decided range of around 160 km.While the ASTRA Mk 1 uses a single-pulse smokeless solid-fuel motor, the ASTRA Mk 2 is reported to be powered by a powerful dual-pulse solid rocket motor, which lets the missile conserve more energy during a flight and also reignite the motor at the terminal phase. This makes it difficult for a target to evade the missiles at long distances.Story continues below this adThis missile variant was granted the Acceptance of Necessity by the Defence Acquisition Council in December last year, indicating the government’s interest in starting the procurement process soon, even as it is still in various phases of testing.Also Read | India, Indonesia sign BrahMos missile, critical minerals deals during PM Modi’s visitAccording to the Defence Ministry, they increased the capability of the fighter aircraft “to neutralise adversary aircraft from a large standoff range”. They will also be integrated into the latest fighter jets of the IAF once inducted.The ASTRA Mk 3 is still under development by the DRDO. Officially named Gandiva, it will be India’s most advanced BVRAAM. It will likely be powered by a Solid Fuel Ducted Ramjet (SFDR) engine, allowing it to maintain continuous thrust mid-flight rather than burning out like conventional rocket motors.Earlier this year, the DRDO had conducted a flight test of its SFDR technology for the ASTRA Mk 3, which could have a range of over 350 km.Story continues below this adWhy is the ASTRA missile critical in the military’s inventory?The missile will be a counter to the long-range PL-15 in use by both Pakistan and China. The PL-15 is an advanced, very long-range, active radar-guided air-to-air missile developed by China.Operation Sindoor, launched by India against Pakistan last year, demonstrated the criticality of longer-range BVRAAM missiles, and ASTRA is India’s indigenous answer to that.A key focus area of the IAF is now to procure more batches of modern BVRAAM missiles. The ASTRA programme will help India build greater self-reliance, instead of depending solely on other imported air-to-air missiles such as the Meteor and R-77.ASTRA’s export potentialStory continues below this adIndia’s deal with Indonesia, signed on Tuesday to supply ASTRA Mk 1 missiles, marking the first export of the missiles to another country, shows that they have good potential for export to other countries as well.India is also set to supply the BrahMos supersonic cruise missiles to Indonesia, as well as to Vietnam and the Philippines. In future, India is likely to explore other friendly countries for the sale of the ASTRA missiles.