In mid-October, China shocked the world with a hypersonic missile test that surpassed US capabilities. Reports claim that this nuclear-capable Chinese hypersonic missile could enter orbit and circle the Earth before changing trajectory to reach its target. This test has raised serious questions about what hypersonic missiles are and why they are dangerous. This article seeks to address questions typically left out of mainstream conversations. Namely, these weapon systems’ potential anti-satellite, or ASAT, capability is left out of the conversation because the fear of possible nuclear capabilities often overshadows more realistic strategic threats.
What are Hypersonic Missiles?
Hypersonic missiles are a relatively new technology built from a continuation of improvement from other ballistic missile programs. However, this evolution in technological advancements is what gives these missiles their “newness” that fundamentally threatens strategic stability because they appear unstoppable, anti-satellite (ASAT), and nuclear-capable. They can travel at around five times the speed of sound (Mach 5) and are highly manoeuvrable, meaning these weapons can change their course mid-flight. The ability to manoeuvre these weapons mid-fight allows them to avoid existing missile defence systems, rendering them almost wholly unstoppable. Two types of hypersonic missiles exist; one is developed, and another is still underdeveloped. The first is glide missiles. Glide missiles are the most common missiles in the US, Chinese, and Russian arsenals. These missiles work by being launched from a rocket, an intercontinental ballistic missile (ICBM), or other airborne systems, letting hypersonic missiles “glide” to their intended target. Cruise missiles, the second type of hypersonic missiles, are self-powered, bringing in the idea of using scramjets or engines that utilise oxygen as fuel. Scramjets are a type of ramjet that is capable of reaching supersonic speed. These engine types operate by compressing air by the pressure of the forward momentum of the aircraft, or in this case, missiles, for fuel combustion.
Who has Hypersonic Missiles and Who Wants Them?
The United States, Russia, and China are the only nations to develop and currently have combat operational hypersonic missile systems. With each having varying levels of capabilities and different stated intentions for producing such weapons.
The United States claims to have hypersonic missile systems designed to strike strategically important targets with conventional instead of nuclear capabilities. In addition, the US arsenal has operational glide missiles with the DARPA program seeking to develop cruise missiles or Tactical Boost Glide Systems capable of reaching Mach-7 through scramjets.
China’s programme has glide missiles launched from ICBMS and their Long March rockets, a fractional orbital bombardment system. In addition, the Chinese possess the most advanced hypersonic missile system capable of successfully launching a missile into space and achieving orbit. The Chinese government has stated that they seek to use hypersonic missiles in conventional warfare with regional targets, citing fears of the development of Russian systems.
Russia’s programme is currently underdeveloped, relying on only ICBM launched, specifically nuclear-capable glide missiles. However, in response to the October 2021 Chinese test, President Putin declared a Russian interest in developing hypersonic missile capabilities further.
The United States, Russia, and China are not the only countries with interest in hypersonic weapons. A host of other nations claims to seek the development of these capabilities for strategic defence purposes, creating a silent proliferation of a destabilising weapons system. I use the term “silent” because the acquisition of these weapons is happening outside the coverage and scrutiny of media and global security discussions. Germany, France, the United Kingdom, Israel, Japan, Australia, and North Korea are nations interested in acquiring such systems. The Germans and French focus on purely defensive capabilities by integrating these weapons into pre-existing air defence systems and future space-based interception systems. While also focused on defence capabilities, Britain, Israel, and Japan expressed interest in hypersonic weapons development to stay up to date with the most modern technological advances and use it for revenue purposes.
The Uniqueness and Importance of Hypersonic Missiles
So what makes these weapon systems so potentially destabilising? Hypersonic missile systems are unique due to two specific capabilities. First, these weapons are highly manoeuvrable. Manoeuvrability in this sense means that while these weapons have a preset target, they can adjust their flight path while mid-air en route to the target, allowing them to dodge and avoid currently existing missile defence systems. Second, the ‘’unstoppable’’ element of hypersonic missiles enables these weapons to have multiple strategic purposes. One of these purposes commonly focused on by the US, China, and Russia is that these missiles can carry out preemptive strikes on military targets. This ability to conduct preemptive strikes can escalate conflict because the ambiguity of these missiles means that they can target systems that other weapons cannot, such as defence networks, command communications, and satellite systems. Moreover, the wide-ranging possible systems these missiles can target increases the potential for successful preemptive strikes that allow further military action.
The second factor that makes hypersonic missiles unique is the cross-domain reach. This means that these missiles apply to discussions of conventional, nuclear, and space capabilities. First, nuclear-capable means that these missiles can carry nuclear warheads to a specific target. These nuclear capabilities, along with conventional capabilities, allows for multiple strategic purposes, such as preemptive strike capability, which has been previously mentioned, and the ability to break through hardened defences. These weapons can enter the Earth’s low orbit, making them also space capable. In theory, these missiles can target and destroy satellites. This satellite targeting capability is not a new concept but is quickly increasing globally with possibly dire consequences to the strategic stability calculations.
The nuclear capabilities of hypersonic weapons should be the least concerning aspect of these weapons. In reality, atomic powers remain, thankfully, unlikely to be used. There are also international laws about which nations can have nuclear weapons, the uses of nuclear capabilities, and what testing can be carried out. Because of these legal restraints, the actual strategic threat from hypersonic missile development comes from the ability to use such missiles to target satellite arrays in low-Earth orbit (LEO).
Hypersonic Missiles as LEO ASATs
The anti-satellite capability of hypersonic weapons represents their most pressing security concern. However, much remains unknown around the legality of ASAT utilisation and what proportional responses could emerge. Satellites are essential to military operations and everyday life, yet the potential risk of harm to these systems is under-reported in mainstream conversations despite legitimate threats. Therefore, it is critical to understand the nature of LEO and the satellite arrays that occupy that space in order to fully understand the potential risks of developing hypersonic missiles.
LEO is a synchronous orbit where satellites and other space-based infrastructures maintain a nearly fixed orbital path, causing them to cross the equator of the Earth at the same local time each cycle. LEO is also home to military satellite systems used for defence systems, military surveillance, arrays for telecommunication, data processing systems, and science installations such as the International Space Station (ISS) and the Hubble Space Telescope. LEO is not the only orbital range that contains critical satellite infrastructure. Geosynchronous Orbit (GEO) is another orbital plane that holds communication, data storage, and mapping capabilities. However, no confirmed GEO ASAT missile capability is reported, so that I will focus on LEO satellites.
Hypersonic missiles capable of entering LEO can damage and destroy any of these satellite arrays or scientific installations, causing immense damage. When it comes to proportional responses, however, significant questions remain unanswered. Taking out civilian satellite arrays can be incredibly disruptive to communication networks but not directly damaging to life, making these attacks similar to cyber attacks. However, in theory, these sorts of attacks make it more possible for an adversary to launch a life-threatening conventional or nuclear attack. Still, an invasion and destruction of a satellite itself are not directly life-threatening. Therefore, most considerations focus not on how to retaliate to such an attack but rather on defending against it. Responding through conventional means to non-loss of life assault on satellite systems may not be a proportional response, especially to avoid further escalation. There is also the risk of indirect attacks when dealing with orbital space. The destruction of satellites within military tests of hypersonic missiles can create debris fields that damage other space installations in the same orbital plane.
An example of this indirect threat of ASAT attacks is the Russian ASAT test on 16 March 2021. In this test, the Russians targeted and destroyed one of their satellites, which, in turn, created a large debris field that directly threatened the ISS. In response, NASA had to advise the astronauts and cosmonauts stationed on the ISS to take emergency actions to ensure their safety in case of a collision with space debris. Both NASA and the US Department of Defense openly condemned this Russian test, calling it reckless and dangerous. Examples of the indirect threat caused by ASAT capabilities brings up a series of questions. How do countries deal with the possible consequences of ASAT tests? What form of retaliation, if any, would be proportional and necessary to hold governments accountable for such reckless and dangerous tests? Does the possibility of proliferation of hypersonic missiles make such threats more likely to occur? The ability to answer these questions is essential for policymakers worldwide to maintain a plan for controlling possible escalation caused by hypersonic missile ASAT capabilities.
What to do about Hypersonic Missiles
Hypersonic missiles are no longer a thing of science-fiction. They represent a real threat to strategic stability. Hypersonic missile systems are nuclear-capable, and they pose a more significant threat to space-based installations in LEO. However, unlike nuclear weapons, conventional attacks against satellite and space installations are still in a legal grey zone because there are no clearly defined limits of development and use. In addition, there is no proper understanding of what a proportional response to such attacks would be. Because of this development and interests in consequence of these capabilities, governmental and military officials must start leading conversations about the real threats about these systems so, as a global community, we can create legal boundaries to address and curb the real danger of hypersonic missile use.