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Breaking Barriers in the Era of Hypersonics

With the country currently running two hypersonic programs in its military research and development pipeline, it is becoming clear that hypersonic weapons and systems may very well represent the next major development in military aerospace with immense potential for industries and governments alike. The Hypersonic Technology Development Vehicle (HSTDV) that India is aiming to develop indigenously has already undergone a first phase of testing in 2019 undertaken by DRDO to understand the complexities associated with the development of this system. In addition to the HSTDV, the nation is currently partnering with one of its closest military allies, Russia, in a bid to collaborate for the development of the Brahmos Mark II(K) missiles through its private sector joint venture corporation BrahMos Aerospace. In this Era of Hypersonics that seem to be upon us, the article seeks to undertake an evaluation of the key research and development challenges associated with Hypersonics, along with an overview of an adequate development strategy that the country may need to execute in order to ensure that it can take advantage of the nascency of this particular technological domain.

A. Research, Development and Analysis of Hypersonics: The Challenge

From an execution standpoint, with respect to the key areas of research pertaining to hypersonic technologies, it must be ensured that the ground test facilities are adequate across all the speed ranges that constitute ‘hypersonic’. Whilst it may be achievable for lower speed ranges, but generally it is observed that the availability and efficacy of test facilities is harder to achieve for higher speed ranges in the hypersonic category. The right critical technology areas must be identified for each deployment mechanism utilized, with extensive testing along the identified technical parameters and testing considerations. Though, yet, three main challenges persist.

(i) Material Development

Perhaps the most crucial technical challenge, by far, facing any hypersonic weapon development process is the material it is made of. The defense industry is no stranger to the challenge of creating advanced materials, but hypersonic weapons take it to a whole new level. An object traveling at Mach 5 or higher speeds builds up an intense amount of heat as it travels through the atmosphere from the myriad gases and particles it travels through. As an objective, real-life point of reference, the Lockheed SR-71 “Blackbird” cruising at 85,000 feet at Mach 3 velocity had to deal with temperatures of over 500° F across most of the surface area of the aircraft. Similarly, the X-15 routinely had to deal with temperatures of up to 1,200° F at Mach 6. We know that the X-15 worked, but let’s remember that the hypersonic range goes from Mach 5 to Mach 25. We’ve barely even scratched the surface of the sort of heat a hypersonic weapon needs to be able to withstand, specially when one puts into perspective the fact that lava, when erupting from a vent, reaches temperatures in the range of 1300° F to 2,200° F. We are talking about temperatures incrementally higher than that when approaching at the upper spectrum of low-hypersonic speed range or nearing the high-hypersonic speed range.

For hypersonic weapons to be successful, their material must be robust enough to withstand the rigors that the speed and heat of hypersonic travel while protecting the delicate instrumentation inside. Since range and speed are paramount for weapons like this, it also must be light enough to not add extra weight or hurt the missile’s manoeuvrability. It needs to have an advanced thermal management system. Finally, it needs to be cheap enough to be easily mass-produced. These trade-offs present engaging and intriguing challenges to Hypersonics developers.

At this point in time based on our current technological prowess, such materials are hard, if not impossible, to come across, and the development of such materials presents a range of difficulties and opportunities for the defense and aerospace industries. Material development of this calibre mandates substantial research and funding. Given that most legacy systems are built around legacy materials, much of the technology that goes into hypersonic weapons will likely need to be rebuilt from the ground up to account for the new material. Where this new material will be found, how available it will be, the cost per material all of these are challenges that will need to be overcome.

On the other hand, there is a wealth of opportunity in developing this material, outside of the paradigm of national security benefits. Any material developed satisfying all of the above criteria would be such a massive leap forward in technology that it would all but require an examination on if it should see more widespread adoption across the defense establishments (such as DRDO and the tri-services) and the ecosystem, and even into the civilian community at large. Most such materials would end up falling in the ‘dual use’ technological classification, capable of being utilized across sectors. Any thermal protection systems developed for hypersonic weapons would absolutely have a use in other situations. Developing material and systems for hypersonic weapons is an incredible challenge, but one with a strong possibility of long-term benefits.

The primary need at this point is to maximize DRDO and defense industry’s ability to develop and test new material and to figure out a way to mass-produce it. As noted previously, test ranges capable of rigorously taxing any new material are absolutely essential to this process. The defense industry will need to collaborate, both among themselves and with the scientific community, to quickly come up with the best possible material. Manufacturing processes need to be streamlined and optimized, and when delivering any new material considerations such as whether it is compatible with ground-breaking, transformational technologies within the manufacturing domain such as 3D printing / additive manufacturing techniques, must be considered. This is an opportunity for the defense industry to make extensive use of R&D funds that can be availed from the defense establishments through various initiatives and schemes in order to fuel this innovation.

(ii) Propulsion Systems Development

Along with the development of materials, another aspect is equally crucial to be factored whilst developing or even ideating Hypersonics – how will these weapons be propelled to the hypersonic speeds required? Once again, the defense industry is no stranger to powerful engines, but hypersonic flight mandates a completely new level of engineering. Propulsion systems exist that can reach hypersonic or greater speeds, such as the sort of rockets that propel ballistic missiles. Such systems are enormous, however, and are incapable of sustaining hypersonic speeds for long durations. Current hypersonic propulsion system development efforts are based primarily on theory, with little true actualized development that could yield an efficacious prototype thus far. In short, current technology is still nowhere near what the defense forces need to make hypersonic weapons work feasibly.

There are certain key considerations for the design, research and development of propulsion systems for Hypersonics, and accordingly they must be lightweight, rugged, cheap, and easy to mass-produce. The propulsion systems also need to be perfectly integrated with any navigation systems to allow for these weapons to accurately strike their targets at the necessary speeds.

As was the case for our analysis regarding the development of materials, certain similar considerations arise during the development of propulsion systems as well. Testing ranges and laboratories for developing these propulsion systems and putting them (and the materials they comprise of) are crucial. This level of engineering will necessitate collaboration in the public and private sectors to minimize the timeline for developing the requisite technology in minimal time. Informed acquisition strategies will also aid this process by ensuring that the supply chain is robust enough to cut out unnecessary delays as the Indian defense establishment and industry experiment and research. Moreover, propulsion system development has to work in tandem with materials development in order to safeguard against any late-stage inconsistencies. These systems will require the same material and thermal protection systems as the rest of the missile, yet they are perhaps even more crucial to protect given that the primary benefit of the weapon is derived from the propulsion system.

(iii) Sensors and Communications Development

As part of the developmental cycle, it is also important to identify the infrastructure that will go with Hypersonics. Beyond sheer speed, a major benefit to hypersonic weapons is that they tend to fly significantly lower than ballistic missiles; in the upper atmosphere rather than in the low earth orbit. The vast majority of ground-based radar stations - the core of most air defense capabilities available to nations - simply cannot see a hypersonic weapon at those altitudes until it is extremely close. This provides difficulties for the side launching hypersonic weapons, as incredibly basic operations such as communicating with the missile become a significant challenge.

Developers of Hypersonics must remain cognizant of the fact that Hypersonics are meant to be more than just ballistic missiles, they should be able to change their trajectories in flight based on inputs from the operator, whether to confuse the enemy about their projected calculations regarding the intended target, adjust to hit a mobile target, or to update the aim. Once hypersonic flight is attained, there is very little time to adjust in such a manner, so even a momentary lapse in communication can be the difference between a successful strike or an ill-advised catastrophe. Further, the intent to equip hypersonic weapons with nuclear warheads at this time remains unclear, which means that any Hypersonic weapons developed by India must be more accurate and reliable than any being developed by our peer countries.

The pressing need to solve this key developmental challenge is to create sufficient infrastructural capabilities to guarantee complete control and constant, unfettered, secure communication with a hypersonic weapon throughout the duration of its entire flight. Ground-based stations may prove to be insufficient – true control over hypersonic weapons may require an advanced network of satellites and space-based sensors that are well equipped to maintain communication channels, and seamlessly handoff communications with Hypersonics that are ‘in flight’ to the next satellite, and able to transmit information to and from the Hypersonic in real-time with minimal latency issues and delay. Though India possesses an extensive satellite network, even this could prove to be insufficient for the needs of Hypersonics, especially when we consider long-range strike capabilities that enlarge the theatre of war. Naturally, securing requisite funding is the primary challenge – the defense industry is aware that building a single satellite and putting it into space can be quite expensive, much less installing a network on the scale needed here. In addition, political considerations come into play here as well. The most effective method for ensuring full sensor coverage is to position each satellite into a geosynchronous orbit. This means that a satellite capable of tracking and communicating with an object moving at speeds up to Mach 25 would be permanently parked over a particular area of the earth. Many nations will be skeptical at best and fearful at worst of the possible intelligence collection ramifications that positioning a satellite in such a manner would result in, and would likely refuse to allow us to place satellites over them. As a result, DRDO and the defense establishment must simulate, compute and assess the best places to station these satellites in order to maximize their coverage and communication while respecting all territorial claims, which may, in turn, affect how these satellites are developed.

Therefore, this is another key area that we believe requires significant research so as to enable the stakeholders of the defense and aerospace sector to create an affordable, effective satellite network. Breakthroughs are being made in creating small, cheap satellites constantly, and the defense industry can set itself up to make breakthroughs in this technology. Such breakthroughs will also find cross-sectoral applications owing to the kind of situational awareness these innovations would enable, making the development of such network and communication arrays a lucrative project.

B. A Development Strategy for Hypersonics

India already has a strong foundational base that can prove to be pivotal for the development of Hypersonic technologies, creating an edge as well as maintaining it. We already operate around 13 (thirteen) wind tunnels spread across the country, however not all these facilities are capable of operating or simulating Hypersonics research. With 2 (two) hypersonic projects already in the pipeline for development, expected to attain IOC (‘initial operational capability’, i.e. the point wherein a particular technology reaches a stage when it is in a minimally deployable form) by the turn of this decade, it is imperative for India to build a dedicated Hypersonics R&D strategy in order to generate efficacious results. At the outset it is key to outline that in order to make real progress, there is a strong need to lay down a consistent and disciplined path to close the remaining science and technology gaps, foster adequate conditions for concepts of operation to develop, and to enable a framework that can allow for robust testing and deployment of Hypersonics.

The creation of key, measurable, identified, long-term goals based on the experiences of R&D visionaries must be kept in mind whilst creating a roadmap for development of hypersonic technologies (whether in the form of weapons or in the form of vehicle prototypes), in addition to learning from the historical development that Hypersonics have experienced across the globe. The contents of this section have been outlined with the same long-term goals and translated learnings in the backdrop, to ensure that Indian investment into the Hypersonics industry can, both metaphorically and literally ‘break the barrier’. However, with the right impetus and positioning, the country can both ramp up its hypersonic capabilities from a strategic POV, whilst also ushering a wave of innovation that can give the country’s defense and aerospace industries, across multiple tiers and component levels, the right thrust to capture the constantly growing hypersonics market.

(i) Exploring Academic Partnerships

There are several technological paradigms and areas within Hypersonics wherein fundamental investigations are ideally suited to university and academic research, specially those pertaining to theoretical and numerical predictions, innovative experimental testing and physical modelling.

Such key research areas could be facilitated through partnerships based on promotion of information sharing and engagement, encouraging cooperation with counterparts based domestically across the Hypersonics research community in the country. For instance, some of the Academic Partnerships can be created for formulating inventive ideas for the control and manipulation of a variety of flow and thermal phenomena in hypersonic flows, including, inter alia, research initiatives around shock wave structures, heat transfer and thermal transport, wave drags, shock wave unsteadiness, viscous and dissipative kinetic heating, thermal acoustic heat transfer, wave induced heat flux, rarefaction effects and slip phenomena, gas dissociation and plasma effects.

In addition, funding and bureaucratic arrangements should be undertaken to enable the government funding entities to reach out to more academic institutions, in order to increase their access to new academic leaderships and to arrange more partnerships and interactions within the Hypersonics research community.

A delineation of key technological areas that have not been pursued in a significant manner by the defense research establishment should be well coordinated across multiple academic institutions, with the provision of enabling access to the required facilities necessary for undertaking such experiments and studies. Added value can be realized by expanding the breadth of existing programs in order to encourage faculty and student fellowships, enable laboratory and center visits, along with provisioning research grants and contracts on key thrust areas within Hypersonics.

(ii) Accelerating Test Facility Creation

At the outset, one of the key parameters that policies must be cognizant of is to ensure a consistency in funding and avoid falling into the trap of ‘cyclical funding’ which creates related problems around brain drain, momentum loss and facility degradations. These facilities are intended to simulate the unique conditions experienced by a missile in hypersonic flight including the speed, pressure, and atmospheric heating effects unique to travel at hypersonic velocities. The development of Hypersonics is undoubtedly centred around the premise of having adequate prediction models, based on accessibility to such ground & flight testing capabilities.

If an R&D pipeline for Hypersonics is sought to be created, a very likely roadblock can be a saturation of key hypersonic wind tunnel facilities (“HWT Facilities”) in the country, which would mandate the creation and operationalization of more such facilities as a matter of priority. This is even more critical owing to how most HWT Facilities take anywhere from 5 to 10 years to design, build and operationalize. The window of opportunity to act is ever thinning as China has already put its resources behind creating an entire suite of new HWT Facilities. Further, policies also need to focus on generating an uptick in the present flight test facilities present in the nation, in order to both bring down the cost per flight test in the long run as we master the curve, as well as increase the generation of flight test data and encourage self-dependence.

(iii) Dedicated Simulation and HPC Facilities

In addition, computational simulation must also be leveraged through enhanced focus on simulation facilities available in the country, as it has large untapped potential for improving the technological and research process through verification, validation and vehicle development simulations. In order to bridge the science and technology gap further, dedicated simulation facilities must possess the ability to run hypersonic computation fluid dynamics (CFDs) models for assessing a plethora of factors involved with Hypersonics R&D such as high temperature effects, turbulence, boundary layer transitions, rarefication effects, ablation, shock-on-shock and shock-on-boundary layer interactions, combustion and fluid, thermal, structural interactions.

To be able to adequately address this challenge, policymakers should ensure that dedicated, and modernized High Performance Computing (HPC) programs are undertaken for Hypersonics R&D in order to tackle the most critical mission challenges. There must be a shift from relying on the extant approach of physical tests as the preferred choice for design development and generating actionable engineering data, to a more digital-based model through implementation of the ‘digital twin’ concept to use physics-informed analysis and virtual test simulations in order to continually upgrade design iterations and generate engineering data that can be utilized for cutting down the R&D cycle substantially. The funding for these HPC facilities can be leveraged through partnerships with stakeholders in the defence ecosystem by providing them access to the simulation facilities and creating a repository of verification and validation models undertaken.

(iv) Enhanced Industry Participation

The development of Hypersonics, an area which has long been a rather unexplored concept amongst Indian industries, requires active, prolonged and symbiotic collaboration between the Industry and the defense establishment in order to yield successful results. This industry participation can be facilitated through a wide range of efforts. The chief focus for the nation should be for India to create a robust ecosystem for manufacturing as well as R&D to sustain the entire life cycle of the product whilst creating jobs and export potential. With the upcoming Defence Industrial Corridors in the country, there is immense potential for such integration to be undertaken for the industrial players.

There is also a need for creating and nurturing an ecosystem of industries specialized in various disciplines required for the development of Hypersonics, from propulsion system manufacturers to communication system developers. Dedicated efforts towards ensuring that these industries can maintain their production lines will not only kick-start the domestic industry on their path towards Hypersonics, but also create a stoic industrial supply chain promising incremental benefits in the future.

Further, industry and academic partnerships should be encouraged heavily for Hypersonics, given their highly experimental and research-intensive nature at this point of time. This can be executed through the formation of research facilities that may be shared between the academic institutions and companies, or through the co-location of certain aerospace R&D infrastructure and expertise that can enhance collaborative R&D projects and provide students / recent graduates with practical learning experiences. This would also help in attracting foreign investment into India as foreign-incorporated corporations or their Indian subsidiaries notice the rise and development of the talent pool in the nation catering to a highly sought-after specialization within the larger aerospace and defense domain.