Indian Defence Review

Most of us are made to believe that hypersonic vehicle technology is the latest and modern invention. But a peep into the technological advances made by Germany in 1930s tells a different story. In spite of restrictions imposed on Germany after WW I, German scientists found a loophole in Treaty of Versailles and found a way to continue work on the rocket technology. Hardly known and rarely mentioned ‘Amerika Bomber’ project was one such project, which envisaged striking mainland USA. Conceptual weapon named ‘Silbervogel (Silver Bird) was the first ever concept of a boost glide hypersonic vehicle.

Fast forward to beginning of 21st century. With the break up of erstwhile USSR in 1989, the post 2nd WW ‘cold war’ era effectively came to an end. But the super power rivalry generated weapons race did not come to a close. In fact a third power was taking giant strides riding on concept of ‘reverse engineering’ and was trying to match the earlier super powers. China’s emergence as a major technological powerhouse took wings in early 70s. By the beginning of last decade of 20th century China had arrived and aimed at becoming an aerospace and maritime power simultaneously.

China’s entry into weapons development race has been remarkable. One such platform, which has invited the attention of entire world, USA, Russia and China, in particular is the development of hypersonic vehicles.

Hypersonic vehicles fly through the atmosphere/space at speeds in excess of five times the speed of sound. As on date no operational hypersonic platform exists, although tall claims have been made by few nations. Frenzied development of hypersonic platform is being resorted to because of the belief that this platform will have the following characteristics in addition to being ‘super-fast’;

• Difficult to detect.
• Difficult/nearly impossible to intercept.
• Reduce warning time markedly.

World is currently witnessing hypersonic platforms as weapon delivery system race. Let each issue related to hypersonic platform be examined.

Cost. Although actual costs of hypersonic vehicles is not readily available in public domain but it is reasonably safe to assume that it would be many times more expensive than the existing ICBMs.

Benefits. As on date the benefits of hypersonic platforms appear to be marked reduction in warning time to the target nation.

It would be appropriate to mention few past/existing projects.

Dyna Soar Hypersonic Glider. US space programme specifically related to placing man on the moon was taking shape in early 60s. Unknown to the world USA was also trying to develop a hypersonic vehicle. But the project was shelved for unstated reasons in early 60s in spite of having spent few billion US dollars in the project. The unstated reason appears to be the fact that the then existing ICBMs were deemed superior to unproven hypersonic vehicle, both in terms of cost as well as operational efficacy.

Development of extremely accurate cruise missile systems added substantial punch to armouries of nations possessing cruise missiles. Employment of this platform during Op Desert Storm I in 1991 proved to be a near perfect example of overall effectiveness of cruise missiles.

Limitations of Hypersonic Vehicles

• Disproportionately huge cost vis-à-vis Ballistic Missiles.
• Meagre bnefits by way of reduced warning time to target nation.
• Hypersonic vehicles fly through the atmoshphere creating huge ‘heat’ signature, which is easily picked up by numerous satellites. On the contrary existing Ballistic Missiles are vulnerable for detection during boost phase only.
• No clear objective of deploying the Hypersonic Vehicles.
• Swarm of IR drones in head on mode might be effective weapons to intercept the incoming hypersonic weapon.

Promoters of the new platform have, however failed to clearly establish the advantage of new vehicle. In fact simulation on computer has shown that many perceived claims/advantages of hypersonic vehicle over existing missile is either false or over-stated. Indeed there is a distinct advantage as well; hypersonic vehicles fly low altitude trajectories, hence cannot be mistaken for a nuke attack. In fact using such weapon platform against non-state actors might be more beneficial.

Technical Aspects. Launch of hypersonic vehicle is accomplished in identical manner by rockets as is the case with ICBMs. After launch during the coasting phase an ICBM is flying through ‘no drag/low drag’ region in the vacuum of space, however hypersonic vehicle flies through atmoshphere and is thus subjected to huge drag force. The drag causes skin temperature of hypersonic vehicle to rise. Hot objects emit light in infra red region. This heating becomes the most dangerous threat to the vehicle. Satellite mounted sensors pick up the heat signatures easily and identify presence of the vehicle. China is fast catching up with USA and Russia to develop this technology. Unlike ICBMs, which are visible only during launch/boost phase, the hypersonic vehicles are visible during the entire flight making it susceptible to interception.

Ongoing Projects

USA. Raytheon and UofA have partnered to develop a hypersonic delivery vehicle based on X-51A, Waverider. Department of Defence has sought budgetary support of about USD 10 Billion out of which nearly 100 million has been allocated towards research. In fact limited availability of hypersonic wind tunnels is causing delays in development.

China. Chinese claims of having developed an operational hypersonic vehicle based on DF-21 is in public domain. This is being touted as an ultimate threat to US super carriers with CEP of less than 50 meters, terminal guidance by vehicle mounted radar and high maneuverability in terminal phase.

Russia. Russia claims to have developed and operationalised hypersonic vehicle named AVANGUARD, which can attain speeds in excess of Mach 20 and is nuke capable.

Many military strategists believe that operationalisation of hypersonic vehicles will alter the threat boundaries and will penetrate missile defenses. Yet another aspect of high maneuverability is also under doubt. Even altering directions by few degrees might impinge huge ‘g’ forces on the structure of hypersonic vehicle and might cause structural failure before impact.

From the above it s quite evident that hypersonic vehicles cannot out perform existing SSMs except in the area of reduction of flight time. Therefore claiming it to be revolutionary weapon platform might just by ‘hypersonic hype’.