Hypersonic Weapons: A War-Changing Technology, or an Excessive Capability?

Hypersonic weapons, in their truest form, are capable of speeds above mark five, have in-flight maneuverability controls, and can perform these tasks while maintaining a low altitude through boost, midcourse, and terminal phases of their trajectory.¹ If such ambitious goals can be achieved by the countries in pursuit of these weapons, there are admittedly few currently operational capabilities to reliably defend against these weapons, whether conventional or nuclear-armed. They can hold hostage carrier strike groups, missile and air bases, or critical infrastructure worldwide.² Advertised as a generational leap in missile technology, governments are investing billions of dollars in R&D to develop hypersonic capabilities, threaten their adversaries, and gain an unquestionable advantage in future conflicts.³

The above paragraph reads not unlike those put out by militaries and their governments around the world and has served as the basis for the overwhelming amount of attention that hypersonics have received in the last several years, as they moved from science fiction to “theoretically operational,” depending on the source. Yet there are real and credible uncertainties regarding the capabilities of these weapon types. Whether it be the shooting down of “hypersonics” in Ukraine, the simple physics challenges of creating an object capable of true hypersonic flight, or most importantly, the question of whether they will pose a greater threat to targets than existing missile technologies already do.⁴

The Basics

Two distinct categories of hypersonic weapons systems are recognized worldwide. The first is the hypersonic glide vehicle (HGV). This system is attached to long-range rocket boosters exactly like Intercontinental Ballistic Missiles (ICBMs). These booster rockets propel the missile to high altitude and then separate from the missile, leaving the warhead to descend to the target via “gliding.”⁵ The difference from traditional ICBMs is that after separation from the boosters, the HGV can maneuver and completely change course while maintaining speeds greater than Mach 5 (many are much faster). This maneuverability allows for missiles to be launched at a flatter, and ultimately lower, trajectory than ballistic missiles, and fly under ground-based radar detection systems for a much greater period before impact.⁶

The second type is a Hypersonic Cruise Missile (HCM), which has more traditional low-altitude launch systems from ground, sea, or air launch vehicles. These missiles, unlike HGVs, never enter high altitudes making them even more difficult to spot over the horizon as opposed to HGVs. HCMs are powered by scramjet engines, allowing them to achieve hypersonic speed while following a similar trajectory to a traditional cruise missile. While scramjet technology is still largely in its preliminary testing phases, they have a theoretical capability to travel at speeds from Mach 5 to Mach 25. For a note of context, the US Tomahawk Cruise Missile, one of the most widely used modern combat missiles, has a top speed near 885 kph (about 550 mph), less than Mach 1, and several times less than that of any future HCMs.⁷

Problems

It would be remiss to speak on the capabilities of these two hypersonic designs without mentioning that these are stated future capabilities, not current testbed results. Russia has tested the largest number of hypersonic weapons, yet their lack of success in Ukraine with their Khinzal missiles, (simply a modified conventional missile if researched with a skeptical eye toward government claims), has cast doubt on hypersonic missiles being introduced into combat any time in the coming years. Problems such as the heat experienced when traveling at high Mach speeds can cause plasma sheathing around the body of hypersonics, causing sensor malfunctions and computer and communication blackouts. While this is not an insurmountable problem, it is just one extra hurdle that adds time, and cost, to development. Furthermore, there are physical and material science limitations to creating an object that is durable enough to endure high G-forces, and still be light enough to perform efficiently in either gliding HGV or scramjet HCM form.⁸ World governments are quickly investing in anti-hypersonic technology, such as satellites that can detect their heat signature and hardening of targets. Lastly, with the intense cost of creating even single hypersonic weapons at the moment, their mass-use capability without bankrupting a state comes into question if current manufacturing economies do not improve.⁹

However, looking through history, there are many instances where new air or space technology was claimed to be impossible. Be it the Wright brothers’ first flight, or the launch of the first satellite Sputnik. World governments would be wise to recognize the intense engineering, control, and physical challenges facing even the most advanced nations in developing hypersonics, yet stay well aware of the powerful consequences if any nation(s) become successful in that endeavor.

A Threat to Mutually Assured Destruction?

Mutually assured destruction, a doctrine of thought that came to prevalence during the Cold War, is predicated on survivable forces on all sides of a nuclear conflict, as well as being able to penetrate a country’s defensive systems with one’s offensive capabilities. Hypersonic weapons were first developed to bypass improved defensive capabilities of nations, particularly the building up of US missile defenses.¹⁰

Hypersonic weapons are an inherent risk to this system according to many experts, as these weapons in their full form would be able to evade current missile defense systems, and their precise targeting systems may be able to take out some of a country’s nuclear weaponry, removing much of the consequence for striking first and creating an inherently unstable system that rewards the aggressor. The current missile defense system is primarily reliant on spotting current ICBMs when they are in the upper atmosphere, tracking their predictable flight pattern, and striking them while in the air. Hypersonic weapons, however, can maneuver much closer to the ground. This means ground-based radar stations are late to alert when one is approaching, and their speed and maneuverability make them nearly impossible to strike out of the sky when in full boost traveling several dozen times the speed of sound.¹¹

All of this makes analytical sense, hypersonic weapons have obvious technical benefits over previous generations of missile systems. However, in the larger scheme of how they affect strategic stability, it seems they do much less than their overwhelmingly grandiose capabilities suggest. Firstly, it does nothing to combat the survivability of nuclear-armed submarines, something that no missile, no matter its speed or maneuverability can target.¹²

Furthermore, despite advancements in anti-ICBM technology in the US and elsewhere, there are no strategic theater mission sets that can uniquely be achieved only through hypersonic weapons systems. The current generation of missiles is more than capable of threatening any current targets either through lone capabilities or the capabilities of combined weapons systems through coordinated strikes. This projected offensive/defensive mismatch in capabilities is widely expected to persist for the next decade if not further, which begs the question as to why so much investment would be poured into a program that has such questionable capabilities, a high cost of development, and performs a task that can already be accomplished, and would only be used in a world-ending scenario nonetheless.¹³ One answer is national pride, another is their capabilities in conventional warfare.

Conventional Risk Factor

The conventional risk factor emerges when you look at the deployment of conventionally armed hypersonic missile systems against conventional targets. As of March 2023, the Pentagon was especially concerned with hypersonic systems being deployed in an anti-navy type of warfare.¹⁴ Current aircraft carrier, destroyer, and cruiser U.S. Navy and their Chinese counterparts’ ships are equipped with sophisticated antimissile defense systems.¹⁵ Still, these have been built and designed for traditional anti-ship offensive weapons, not at HCM/HGV speeds above Mach 5 to Mach 20. While there are some capabilities the US Navy has to defend against hypersonics, SM-6 missile defense systems, these are newly deployed or retrofitted fixes. Countries like the US, Russia, and China rely heavily on force projection through ship presence in international and territorial waters and use aircraft carriers as floating airports for their airpower launches in any type of conflict.¹⁶ One cause for concern is the war-fighting effects between the great three powers of Russia, China, and the US, and the damage-causing capabilities that these weapons systems can have on each other’s navies in the future.¹⁷

The second cause for concern would be the use of hypersonics in conventional ground-based conflict, as has been done in Ukraine with little success, which can in part be attributed to the newness of the weapons systems, an overstating of capabilities on the part of the Russians, and the ability of US defense systems to track “hypersonics” in their slower moving phases.¹⁸ All this being said, in the future where many of the newer issues with hypersonics have been ironed out, ground-targeted hypersonics threaten to change some of the various tactics that are already being shifted by emerging technologies such as drone warfare. Spacing of bases, hardening of targets, radar warning stations and their locations, and the actual missile defenses themselves are all at risk of becoming antiquated by a successful hypersonic program in the future. Additionally, while tank warfare and slow-moving armored columns are already proving to be less than decisive in the Ukraine conflict, their ease of “targetability” could make them even more vulnerable with the creation of hypersonic weapons systems en-masse.¹⁹

Conclusion

If you fast forward several decades, it is possible that hypersonic weapons will be in the arsenal of many militaries around the world. It is also equally likely that defense capabilities will have evolved alongside hypersonic weapons to attempt and keep pace with their new fast strike capabilities. The threat lies in the interim, in which the development of these weapons has, and will continue to, outpace the defensive capabilities of nations around the world. There is currently little threat to the strategic stability of the MAD doctrine because of these weapons, thanks to hardened targets, and especially submarines, yet there should be cause for concern about their ability to better pierce missile defenses in the future, especially if technology emerges that makes tracking and detecting submarines easier, in which case effective hypersonic missiles may pose a threat to MAD.

The strategic stability question lies mainly in debate and conjecture, yet the conventional capabilities of hypersonics and their effect on conventional targets are more steadfast. In the coming years, the development of hypersonics by powerful militaries around the world could pose a threat to traditional land and sea-based slow-moving targets, such as ships of all types, tanks, and other armored battalions. They also pose a threat in air-to-air or air-to-ground combat. In the coming years, countries around the world should spur development into studying the evasive capabilities of hypersonic Weapons Systems and develop defense techniques to defend against them. Whether that be through the strategic placing of targets, deciding what ships/armored divisions to deploy (or not deploy), or conventional/new military missile defenses. These include lasers, microwave weapons, and space-based detectors.²⁰

Lastly, hypersonics should be targeted as a new opportunity to pursue Arms Control agreements between major players in the field, to close the gap between their offensive capabilities and the current defensive capabilities of Nations around the world to ensure some level of stability.²¹

Riley Worth

Riley is an Undergraduate at the University of Southern Maine obtaining a Bachelors degree in both Political Science and Economics. He is a past attendee of the John's Hopkins Kissinger Academy, and conducted an Undergraduate thesis on US/China military comparisons. He has been involved in United Nations conferences in the Northeast and has also Chaired the UNSC council for Maine's Model UN. He is currently beginning his term as the Student President of his University, and plans on entering domestic politics after further education and experiences.