Questioning the ‘Disruptiveness’ of Hypersonics

Recent reports suggest that China has tested hypersonic glide vehicle (HGV) based missile.[1] Though China has denied it, the US security establishment has also acknowledged the test.[2] Previously, Russia had also carried out the test of Avangard HGV.[3]

Hypersonic glide missiles are manoeuvrable weapon systems that move faster than five times the speed of sound. Unlike a ballistic missile that follows a fixed projectile trajectory, glide vehicles use pull-up and re-entry trajectories to manoeuvre.[4] It is claimed that this not only can increase the range and accuracy of a missile but can also deceive the enemy’s air defences.

CC: ucsusa.org

A majority of public reportage are uncritically fascinated by the extraordinary claims made about the capabilities of these weapon platforms. They have been termed as “nearly invisible”, “game-changer”, “unstoppable”, “enabler of next-gen warfare”, etc.[5] In academic circles, many scholars have predicted this as the start of an arms race under the paradigm of a new Cold War between the US and China, having implications for global stability and security.[6] One of India’s top experts on China recently commented that "China has taken the arms race to a different level” upsetting the strategic balance of power.[7]

This essay presents a critique of these opinions and argues that HGV-based long-range missiles' potential in terms of invincibility and instability factors is vastly overstated. At the most, the development of this technology is incremental and not disruptive. Hence, it is vital to separate substance from erroneous perceptions. The first two sections deal with the physical limitations faced by the HGVs followed by the limits of their impact on systemic stability.

The Physics

Using computational modelling, a recent experimental study on hypersonic glide vehicle flight by Cameron L. Tracy and David Wright gave surprising results, contrary to the widespread anticipations. Their analysis shows that these vehicles travel inter-continental ranges more slowly than ballistic missiles flying in low-altitude trajectories. Even though most of their flight is in outer space, the glides are performed within the atmosphere while facing proportional air drag. This reduces the average speed, range, and manoeuvrability. Compared with ballistic missiles, hypersonic glides provide only a modest advantage, which too is inversely related to the range required to be covered.[8]

There are also other constraints to what hypersonic missiles can do. Though it is said that they combine the best of speed, range, and manoeuvrability, however, there is a sought of trilemma formed between these three variables. There are trade-offs involved, and removing these trade-offs is easier said than done.[9] Given the high speeds, it is very difficult to manoeuvre such a missile, especially if targeting a small and fast-moving target.

Similar technical assessments on the effectiveness of HGV warheads had been made before as well.[10] They are best suited for large and slow-moving or fixed targets not situated in intercontinental ranges.[11] The challenges are such that they either are almost impossible to address or require massive pouring of investments in research and development.[12]

Detection and Destruction

Their research also shows that these systems are not entirely invisible for detection technologies, especially space-based infrared (IR) sensors and over the horizon (OTH) radars.[13] They also produce strong and intense heat signatures on launch and while gliding through the atmosphere, thereby detectable by early warning systems.[14] Hence, it is within the capabilities of military powers like the US, Russia, and China to detect hypersonic missiles and even the fractional orbital bombardment systems (FOBS).[15]

Currently, directed energy weapons are being explored to counter hypersonic warheads.[16] These weapons include lasers and high-power microwaves.[17] Electronic circuits onboard hypersonic missiles that are used for control and guidance can be rendered ineffective by high-power microwaves.[18]

From a ballistic missile perspective, it is important to note that even these can bypass air defence systems.[19] This is because the current air defence technologies are in their formative stage, which is best at detecting and destroying comparatively rudimentary ballistic missiles with no counter-measures.[20] With the advancement of multiple independently targetable re-entry vehicles (MIRVs), the evolution of ballistic missile technology is a few steps ahead of air defence technology.

The defence penetration advantage of hypersonic missiles compared to ballistic missiles appears large enough only when one ignores ballistic missiles' well-evolved penetration capability and tactics, like the terminal manoeuvre.[21]

Global Stability and Arms Race

Despite the limitations explained above, the novelty of offensive character of these weapons’ systems cannot be denied. However, the perceived global instability and strategic imbalance of power resulting from these will be short-lived. This is understood when we look at the technological change and the evolution of weapons on a long time horizon.

Historically, we notice that the development of offensive and defensive weapons moves cyclically, i.e. the advent of a new and potent offensive weapon is followed by the invention of a more potent defensive technology against it.[22] Every offensive development is followed by doomsday predictions of being the next 'unmatched' weapon, only to be proved wrong by subsequent defensive development. For example, the invention of tanks and fighter aircrafts has been followed by rapid advancement in anti-tank missiles and radars and sophisticated surface to air missiles (SAM), respectively.[23] Once defences against hypersonic systems emerge, the discourse of instability will evaporate to a large extent.

It is true that arms races are a massive drain on state resources and can even contribute to the collapse of the state. However, given the anarchy in the international system where there is no “911” actor, paradoxically, it is the “delicate balance of terror” that provides a way out to ensure stability by increasing the incentives for the states to have an arms control agreement (AMA).[24]

In a bipolar system, AMAs among the great powers are difficult to reach when only one of the great powers enjoys a technological advantage. It is only when there is a kind of rough technological parity or when the great powers are confident of their defensive capabilities that they participate in arms control talks and subsequently bind themselves. Hence, arms control of hypersonics is most likely to be negotiated and enforced once the US and China have similar technological capabilities or have defences ready against each others' capabilities.

Scholars often warn the policymakers about the risk of getting trapped in the rhetoric leading to bad analysis of the situation and subsequently to poor policy responses. Yes, hypersonic weapons do offer some unique capabilities; however, it is vital to critically assess their capabilities beyond the hype.

Evidence-based scrutiny is important for policymakers to take rational and well-evaluated decisions regarding the value of HGV to global (in)security and this needs to be done alongside all other available alternative platforms. Over-estimating the threat posed by them can result in unintended negative consequences for global stability, risking escalation of competition into a conflict.

Notes

[1] Financial Times. (2021). China tests new space capability with hypersonic missile. https://www.ft.com/content/ba0a3cde-719b-4040-93cb-a486e1f843fb/ .

[2] Reuters. (2021). China denies report of hypersonic missile test, says tested space vehicle. https://www.reuters.com/world/china/china-disputes-report-hypersonic-missile-test-says-tested-space-vehicle-2021-10-18/.

Business Standard. (2021). United States concerned over China's hypersonic missiles: Joe Biden. https://www.business-standard.com/article/international/united-states-concerned-over-china-s-hypersonic-missiles-joe-biden-121102200133_1.html/.

[3] Missile Threat. (2021). Avangard. https://missilethreat.csis.org/missile/avangard/.

The New York Times. (2019). Russia Deploys Hypersonic Weapon, Potentially Renewing Arms Race. https://nytimes.com/2019/12/27/us/politics/russia-hypersonic-weapon.html/.

[4] Congressional Research Service. (2021). Defense Primer: Hypersonic Boost-Glide Weapons. https://sgp.fas.org/crs/natsec/IF11459.pdf/.

[5] Smith, R. Jeffrey. (2019). Hypersonic Missiles Are Unstoppable. And They’re Starting a New Global Arms Race. The New York Times Magazine. https://nytimes.com/2019/06/19/magazine/hypersonic-missiles.html/.

Simon, Steven. (2020). Hypersonic Missiles Are a Game Changer. The New York Times. https://nytimes.com/2020/01/02/opinion/hypersonic-missiles.html/.

Statement for the Record. World Wide Threat Assessment. Robert Ashley. (2018). Armed Services Committee United States Senate https://armed-services.senate.gov/imo/media/doc/Ashley_03-06-18.pdf/.

Thompson, Loren. (2019). Defense Against Hypersonic Attack Is Becoming The Biggest Military Challenge Of The Trump Era. Forbes. https://www.forbes.com/sites/lorenthompson/2019/07/30/defense-against-hypersonic-attack-is-becoming-the-biggest-military-challenge-of-the-trump-era/.

[6] Lewis, Jeffrey. (2021). China’s Orbital Bombardment System Is Big, Bad News—but Not a Breakthrough. Foreign Policy. https://foreignpolicy.com/2021/10/18/hypersonic-china-missile-nuclear-fobs/.

CNBC. (2018). Russia and China are ‘aggressively developing’ hypersonic weapons — here’s what they are and why the US can’t defend against them. https://www.cnbc.com/2018/03/21/hypersonic-weapons-what-they-are-and-why-us-cant-defend-against-them.html/.

[7] Kondapalli, Srikanth. (2021). China has taken the arms race to a different level. Deccan Herald. https://www.deccanherald.com/opinion/china-has-taken-the-arms-race-to-a-different-level-1057727.html/.

[8] Tracy, Cameron & Wright, David. (2021). Modelling the Performance of Hypersonic Boost-Glide Missiles. Science & Global Security. 28. 1-27. https://doi.org/10.1080/08929882.2020.1864945/. https://scienceandglobalsecurity.org/archive/sgs28tracy.pdf/.

[9] Tracy, Cameron & Wright, David. (2021). Modelling the Performance of Hypersonic Boost-Glide Missiles. Science & Global Security. 28. 1-27. https://doi.org/10.1080/08929882.2020.1864945/.

Oelrich, Ivan. (2020). Cool your jets: Some perspective on the hyping of hypersonic weapons. Bulletin of the Atomic Scientists. https://thebulletin.org/premium/2020-01/cool-your-jets-some-perspective-on-the-hyping-of-hypersonic-weapons/.

[10] Acton, James M. (2015). Hypersonic Boost-Glide Weapons. Science & Global Security. 23:3, 191-219. https://doi.org/10.1080/08929882.2015.1087242/.

[11] Venable, Heather and Abercrombie, Clarence. (2019). Muting the Hype Over Hypersonics: the Offense-defense Balance in Historical Perspective. War On the Rocks. https://warontherocks.com/2019/05/muting-the-hype-over-hypersonics-the-offense-defense-balance-in-historical-perspective/.

[12] Leyva, Ivett A. (2017). The relentless pursuit of hypersonic flight. Physics Today. 70, 30-36. https://doi.org/10.1063/PT.3.3762/.

Taylor, Laurence and Barrie, Douglas. (2018). Hypersonics and hyperbole: the marathon to develop very-high-speed cruise missiles. International Institute for Strategic Studies. https://www.iiss.org/blogs/military-balance/2018/03/hypersonics-and-hyperbole/.

[13] Missile Threat. (2021). Space-based Infrared System (SBIRS). https://missilethreat.csis.org/defsys/sbirs/.

Radar Tutorial. Over-The-Horizon-Radar (OTH). https://www.radartutorial.eu/07.waves/wa51.en.html/.

[14] SatelliteObservation. (2018). Detecting hypersonics. https://satelliteobservation.net/2018/11/15/detecting-hypersonics/.

[15] Grego, Laura. (2021). Twitter. https://twitter.com/LauraEGrego/status/1449806803764748291/.

FOBS are orbital bombardment systems where the attacker uses a rocket to place a warhead in orbit. This warhead has an attached rocket motor which is fired to slow down the speed of the warhead, thereby de-orbiting at the place of choice over the enemy's territory. To be fair, these do avoid radars when doing low-altitude glides since the curvature of the earth's surface blocks radar's line of sight.

Pollack, Joshua. (2019). Hypersonic Glide Vehicles: What Are They Good for?. Arms Control Wonk. https://www.armscontrolwonk.com/archive/1208662/hypersonic-glide-vehicles-what-are-they-good-for/.

Pollack, Joshua. (2021). Twitter. https://twitter.com/Joshua_Pollack/status/1449512387678191618/.

[16] Obering, III. Henry. (2020). Directed Energy Weapons Are Real . . . And Disruptive. Prism, Vol.8, No.3. https://ndupress.ndu.edu/Portals/68/Documents/prism/prism_8-3/prism_8-3_Obering_36-46.pdf/.

Harper, Jon. 2019. Special Report: The Pentagon Could Put Directed Energy Weapons in Space. National Defense. https://www.nationaldefensemagazine.org/articles/2019/4/25/special-report-the-pentagon-could-put-directed-energy-weapons-in-space/.

[17] Lockheed Martin. https://www.lockheedmartin.com/en-us/capabilities/directed-energy.html/.

[18] Office of Naval Research. Directed Energy Weapons: High Power Microwaves. https://www.onr.navy.mil/en/Science-Technology/Departments/Code-35/All-Programs/aerospace-science-research-351/directed-energy-weapons-high-power-microwaves/.

Military & Aerospace Electronics. (2019). Air Force deploys B-52 missiles that could disable enemy military electronics with high-power microwaves. https://www.militaryaerospace.com/rf-analog/article/14033453/air-force-deploys-b52-missiles-that-could-disable-enemy-military-electronics-with-highpower-microwaves/.

McGonegal, Jack. (2020). High Power Microwave Weapons: Disruptive Technology for the Future.Defense Technical Information Centre. https://apps.dtic.mil/sti/pdfs/AD1107488.pdf/.

[19] Verschuren, Sanne. (2021). China’s Hypersonic Weapons Tests Don’t Have to Be a Sputnik Moment. War On The Rocks. https://warontherocks.com/2021/10/chinas-hypersonic-missile-tests-dont-have-to-be-a-sputnik-moment/.

[20] Sessler, Andrew M. et al. (2000). Countermeasures: A Technical Evaluation of the Operational Effectiveness of the Planned US National Missile Defense System. Union of Concerned Scientists. https://www.ucsusa.org/sites/default/files/2019-09/countermeasures.pdf/.

[21] Oelrich, Ivan. (2020). Cool your jets: Some perspective on the hyping of hypersonic weapons. Bulletin of the Atomic Scientists. https://thebulletin.org/premium/2020-01/cool-your-jets-some-perspective-on-the-hyping-of-hypersonic-weapons /.

[22] Venable, Heather and Abercrombie, Clarence. (2019). Muting the Hype Over Hypersonics: the Offense-defense Balance in Historical Perspective. War On The Rocks. https://warontherocks.com/2019/05/muting-the-hype-over-hypersonics-the-offense-defense-balance-in-historical-perspective/.

[23] Thompson, Loren B. (2012). “The Bomber Will Always Get Through” — 80 Years Later, A Prophecy About Emerging Threats Is Coming True. Lexington Institute. https://www.lexingtoninstitute.org/the-bomber-will-always-get-through-80-years-later-a-prophecy-about-emerging-threats-is-coming-true/.

[24] Mearsheimer, John J. (2001). The tragedy of Great Power politics. Chapter 2. New York: Norton.

Wohlstetter, Albert. (2008). The Delicate Balance of Terror. Survival: Global Politics and Strategy. 1. 8-17. https://doi.org/10.1080/00396335908440116/.

Pic Courtsey-https://www.military.com/equipment/weapons/why-russias-hypersonic-missiles-cant-be-seen-radar.html

(The views expressed are those of the author and do not represent views of CESCUBE.)