The Indian development (of successfully testing hypersonic vehicles) is clearly aimed at countering China

Amidst ongoing tensions with China – and on the same day China's ‘secretive’ reusable spacecraft (akin to the US’s X-37B) landed back successfully – Indian Raksha Mantri Rajnath Singh announced (on 7 September) that “DRDO India has today successfully flight tested the Hypersonic Technology Demonstrator Vehicle using the indigenously developed scramjet propulsion system.”

Defence sources added the ‘cruise vehicle’ separated from the ‘Agni’ missile booster at 30 km altitude, and “India will be making its first hypersonic missile in the next five years.”

With this successful test, India joins a select club developing Hypersonic Vehicles. These travel in excess of five times the speed of sound (Mach-5), and presently, there is no known missile system that can defeat them.

Hypersonic Vehicles: A Brief History

Hypersonic technology can be traced to the work done in Germany during World War II. Post WW-II, research continued in the US and USSR/Russia, with the US developing the rocket-powered X-15 (flown-1959; average speed ~ Mach 6.7). Their development got a boost after the 9/11 attacks.

Reflecting on the many missed opportunities to hunt down Osama bin Laden, US military experts began seeking a system that could be launched from ‘fortress America’ to strike a time-sensitive target on the other side of the world in less than an hour. It was premised that even if they aren’t equipped with a nuclear or conventional warhead, just their massive kinetic energy (mass x hypersonic velocity) would unleash terminal effects equal to a small-size nuclear strike, but without the associated radiation and nuclear fallout.

Hypersonic Platforms Can Be Divided Into Two Main Categories:

Hypersonic Cruise Missiles (HCM): This is typically propelled to high speeds initially using a small rocket, and then, powered to the target by a supersonic combustion ram jet (‘scramjet’) for hypersonic flight. This is what India, under its ‘Hypersonic Technology Demonstrator Vehicle’ /Mach-7 BrahMos-II program, has tested.

Hypersonic Glide Vehicles (HGV): The HGV is a ‘boost-glide’ weapon. It is first ‘boosted’ into near-space atop a conventional rocket, and then released at an appropriate altitude and speed. The release height depends on the intended trajectory to the target. Thereafter, the HGV starts to fall back to Earth, gaining more speed and gliding along the upper atmosphere, before diving onto the target.

Why Pick Hypersonic Vehicles Over Ballistic Missiles?

Intermediate Range Ballistic Missiles (range <3,500-5,500 km>) and Inter-Continental Ballistic Missiles (range > 5,500 km) usually rise to a very high altitude (1000-1200 km). After the various stages burn out, the missile, pulled by gravity, falls on a prescribed course (unless it is a Manoeuvrable Re-Entry Vehicle).

Because these missiles rise so high, they can be detected for interception by anti-ballistic missile (ABM) systems particularly in the mid-course and terminal phase of their flight.

An August 2017 assessment by the Nuclear Threat Initiative premises that the President of the US has just 2-4 minutes to render a decision on intercepting incoming ballistic missiles fired by China/Russia and launch its own missiles against the latter. In case of contiguous nations (example: India-Pakistan; India-China), this timeline would get further compressed.

The detection-interception time in case of HCMs and HGVs, travelling at speeds between Mach-5 and Mach-20, would be far less. Besides, HGVs do not rise above 100-110 km altitude; HCMs fly even lower, at about 20-30 km altitude. Their flatter trajectories vis-à-vis ICBMs, along with the Earth’s curvature, further complicates the dynamics of detecting-intercepting.

Hypersonic Tech Development Across The World

Russia, China and the US are fielding both HCMs and HGVs. Russia began researching hypersonic technology in the 1980s. Of its three programs – Yu-71 ‘Avangard’, 3M22 Tsirkon and Kh-47M2 ‘Kinzhal’ – the Avangard HGV (reported speed ~ Mach-20; ‘unlimited’ range)) is currently operational on the SS-19 ICBM.

Russia, however, plans to shift it to the RS-28 ‘Sarmat’ ICBM – this will carry 03 to 05 nuclear warhead-equipped ‘Avangard’ HGVs along with onboard countermeasures.

The under-development ‘Tsirkon’, a Mach-9 ship-launched HCM (range: 400-1100 kms) is expected to reach initial operational capability (IOC) in 2022. ‘Kinzhal’, an air-launched ballistic missile (claimed range > 2,000 kms; speed ~ Mach-10) is expected to be fully deployed by 2023/2024.

China’s medium range DF-17 HGV, first displayed in 2019, is assumed to be operational.

The Xingkong-2 ‘Waverider’ HGV, may see IOC by 2025. China is also mating an HGV to its long-range DF-41 ICBM rocket, and developing an HCM, the Lingyun-1.

The US has been pursuing hypersonic technology since the early 2000s through programs like the US Navy’s Conventional Prompt Strike; US Army’s Long-Range Hypersonic Weapon; US Air Force’s AGM-183 Air-Launched Rapid Response Weapon; DARPA’s Tactical Boost Glide, OpFires, and Hypersonic Air-breathing Weapon Concept. Most US hypersonic platforms are expected to reach IOC between 2022 and 2028.

Strategic Implications of Hypersonic Tech

The huge number of nuclear warheads and delivery systems with the US and former USSR, coupled with their substantial submarine-based ‘second-strike’ capability, had given rise to the concept of ‘MAD’ (Mutually Assured Destruction) during the Cold War. In turn, this had enforced strategic stability.

ABM systems, with their ability to destroy some of the incoming ballistic missiles, were the first to pose a challenge to strategic stability.

Consequently, the US and USSR transacted the ABM treaty in May 1972 as part of the Strategic Arms Limitation Talks. Without ABM systems, each superpower remained deterred from launching an attack first because it faced retaliation (‘second-strike’) which would assure its own destruction. In June 2002, the US withdrew from this treaty, premising that it prevented the development of ABM defences against possible terrorist/ ‘rogue-state’ ballistic missile attacks. And now, the US, Russia and China possess ABM systems, and many other nations (including India) are either developing or acquiring them.

‘Dangers’ of Hypersonic Tech

However, vis-à-vis ballistic missiles, hypersonic vehicles are far more difficult to detect-track-intercept. Former chief of the US Strategic Command General John Hyten admitted even the US has poor defence against them.

Faced with hypersonic weapons threat and reduced warning-response timings, nuclear-armed states are likely to place their nuclear weapons on a hair-trigger readiness/ ‘launch on warning’ status, and/or delegate control to lower levels.

Both steps hold attendant risks of inadvertent, swift escalation. Additionally, a nation may feel encouraged to attack a nuclear weapons state with an HGV-conventional warhead/kinetic energy strike combo, while assuming, rightly or wrongly, nil risk of a nuclear response from the target nation.

Some nations may consider using HCMs/HGVs pre-emptively to severely disrupt the conventional forces symmetry – and China’s Anti-Access/Area Denial (A2/AD) strategy aligns with this.

Thus, hypersonic weapons, with quick-launch, high-speed, massive terminal effects capability, will encourage adventurism, make escalation control very difficult, and generate not only strategic instability but also instability in crisis management at many levels.

The Indian development is thus clearly aimed at countering China. Pakistan, a linear-shaped nation with limited strategic depth, can be tackled with many other weapon systems.

Why The Hypersonic Arms Race Holds Ominous Portents

That said, developing hypersonic weapons is one thing – exploiting their full combat potential is quite another. One main problem is associated with the need for a series of networked sensors-and-feedback mechanisms – to strike a time-sensitive target thousands of miles away in less than an hour, one needs ‘very definitive, near-real-time intelligence with progressive feedback’.

Overall, the hypersonic arms race holds ominous portents. Both HCMs and HGVs involve esoteric technologies. Operationalising them would also require ‘intelligence, surveillance, target acquisition, and reconnaissance’ (ISTAR) assets.

Besides, nations would be forced to re-think ABM systems and develop new ones at monumental cost. This is bound to impose new, multi-faceted, financially debilitating costs that would be in addition to conventional and nuclear weapons. And once operational (France, Japan too are working on them), they would create new and substantial challenges to strategic stability, as also encourage adventurism. Experts thus warn it’s time to ban them.