Indian Defence Review

On 11 March 2024 the Indian Defence Research and Development Organisation (DRDO) successfully test fired an indigenously developed missile with multiple independently targetable re-entry vehicle (MIRV) technology from Dr. APJ Abdul Kalam Island in Odisha. This test conducted by India as part of Mission Divyastra demonstrated the advancement in missile technology and is an important step towards strengthening India’s nuclear deterrence triad.

Divyastra is a Sanskrit portmanteau formed by two words. Divya meaning “divine,” “celestial,” or “heavenly”, and Astra meaning “weapon” or “missile.” Therefore, the literal meaning of Divyastra is “divine weapon” or “celestial weapon.” In Hindu mythology, divine weapons are powerful armaments wielded by gods and goddesses. They often possess extraordinary capabilities beyond ordinary weapons.

The primary objective of Mission Divyastra was the first flight test of Agni-5 missile equipped with MIRV technology. The MIRV technology allows a single Agni-5 missile to carry multiple warheads, each capable of hitting separate targets for a more effective coverage of the target. The test was conducted with three warheads; however the operational version is likely to have 10-12 warheads. Mastering MIRV technology symbolizes India’s ability to miniaturize nuclear warheads, which is a complex feat. The Agni-5’s extended range, coupled with MIRV, bolsters India’s deterrence capabilities.

Mission Divyastra is seen as a significant advancement towards India’s self-sufficiency (Atmanirbhar) in defense technology. The recent test is an extension of the Agni V intercontinental ballistic missile (ICBM) successfully test-fired by DRDO on 19 April 2012. The Agni V intercontinental ballistic missile can carry a nuclear warhead over a distance of 5000 km and strike any target in both China and Pakistan.

Multiple Independently Targetable Re-entry Vehicle (MIRV) technology involves delivering multiple warheads to hit multiple points over the large strategic target with a single missilecausing more damage than a single warhead – akin to a conventional cluster bomb. MIRV is a complex technology that significantly amplifies the destructive potential of a single ballistic missile. A MIRV-equipped missile carries multiple warheads within a single body. During the final stages of flight, these warheads separate and re-enter the atmosphere on independent trajectories, allowing them to strike at different points of the strategic target.

The main components of the MIRV-equipped missile include:

• • Missile Bus: The main body of the missile that carries the warheads and releases them at a designated altitude.
  • Re-entry Vehicles (RVs): These house the individual warheads and navigate towards their assigned targets. MIRV technology involves miniaturizing warheads to fit multiple RVs within the bus.
  • Guidance System: A sophisticated guidance system on the bus and individual RVs ensures accurate targeting of separate locations.

Some of the key technological bottlenecks behind developing MIRV-equipped missiles include:

• • Miniaturization of Warheads: Shrinking nuclear warheads while maintaining their destructive power.
  • Complex Guidance System: accurate and elaborate guiding systems in the RVs and bus to neutralize multiple warheads.

The MIRV Challenge:

With the introduction of MIRVs, a single missile could launch multiple warheads, making it significantly harder for existing missile defense systems to intercept all incoming threats.

The strategic implications of this technology are increased destructive power as a single MIRV missile can destroy and damage multiple targets.

On the other end defending against MIRV missiles requires advanced radar and satellite technologies and missile defencesystems capable of detecting missile launches, intercepting multiple warheads   and tracking their trajectories. There is also need for faster and more accurate interceptor missiles which have a quick response time to engage incoming threats as well as better chance of successfully hitting and destroying incoming MIRV warheads.

Technological Arms Race:

The history of MIRV technology dates back to the Cold War days when both the US and the Soviet Union started pushed the boundaries of missile technology. The idea of equipping missiles with multiple warheads emerged during this period. However, technological limitations like bulky warhead size and guidance systems hindered its realization.

Several crucial scientific breakthroughs paved the path for the development of MIRVs in the 1960s when the scientists were able to design smaller thermonuclear warheads, allowing for multiple warheads on a single missile.

Another landmark technological achievement was development of space vehicles like ABLE-STAR and TRANSTAGE which served as precursors to the “bus” system used in MIRVs. These vehicles could propel multiple payloads on separate trajectories.

The US is credited with deploying the first operational MIRV system. The Minuteman III missile, successfully tested in 1968, carried three W62 warheads. This was a significant improvement over the single warhead on previous models.

Not to be left behind, the Soviet Union started actively pursued MIRV technology and joined the race to develop and deploy MIRV-equipped missiles, raising concerns about increased nuclear destruction.

By the late 20th century, both the US and the Soviet Union had incorporated MIRVs into their intercontinental ballistic missile (ICBM) and submarine-launched ballistic missile (SLBM) arsenals.

The Shadow of MAD Arms Race:

As missile offence and defence capabilities continue to evolve MIRV technology can lead to development of missiles carrying even more warheads or employing decoys to confuse interceptors.

Intercepting multiple warheads from a MIRV is a complex and challenging task as even the most advanced missile defencesystems are not fool proof or perfect.

There is a growing concern that uncontrolled proliferation of MIRV rivalry can eventually lead to a situation of “mutually assured destruction” (MAD) where both sides possess the capability to inflict devastating damage on the other.  It relies on the concept that a full-scale nuclear attack by one country on another would result in the complete annihilation of both countries.

Mutual assured destruction (MAD) is a doctrine of military strategy which suggests that a full-scale use of nuclear weapons by an attacker on a nuclear-armed defender with second-strike capabilities would result in the complete annihilation of both the attacker and the defender. It is based on the theory of rational deterrence, which holds that the threat of using strong weapons against the enemy prevents the enemy’s use of those same weapons.

This raises a concern about nuclear arms race and the potential for devastating destruction in case of conflict.

The primary purpose of MAD is to deter a nuclear attack. By possessing the capability to inflict unacceptable damage in retaliation, even if attacked first, a country discourages others from launching a nuclear attack against them.

MAD is based on a precarious balance of power between nuclear-armed nations. Each side possesses enough nuclear weapons to destroy the other, even if their defences manage to shoot down some incoming warheads.

Critics argue that MAD is a dangerous and unstable strategy, as it relies on the assumption that rational decision-making will always prevail during times of crisis.