Are hypersonics all hype?
A new article by Dr. Cameron L. Tracy of the Union of Concerned Scientists’ Global Security program and Dr. David Wright of Massachusetts Institute of Technology’s Department of Nuclear Science and Engineering in the journal Science and Global Security calls into question whether hypersonics have the technical qualities to make an impact on the strategic balance of power. These questions come at a time when China, Russia, and the United States have all loudly embarked on hypersonic programs, the latter promising to install hypersonic weapons on an array of surface warships and submarines. In part because of this, the manuscript has received serious attention from mainstream media institutions such as the New York Times, which published a summary and interpretation of its findings.
Analysts, abetted in some cases by military personnel, have worried about the impact that hypersonics could have on nuclear and conventional readiness. The name implies a speed of attack that reduces reaction time, and the novelty of the platform suggests that the weapons can evade existing defenses. Hypersonic weapons have also been decried for their destabilizing effect on nuclear security, as onlookers cannot discern the launch points and targets of the weapons as easily as ballistic missiles. China, for example, might misinterpret the launch of a hypersonic weapon targeting Iran as a first strike, based on the weapon’s unpredictable behavior.
But the enthusiasm for hypersonics has resulted in some conceptual slippage. Ballistic missiles, of course, already approach their targets at hypersonic velocities. And no country can reliably defend against existing sophisticated ballistic missiles, notwithstanding continued improvements in missile defense technology. According to Tracy and Wright, “misperceptions of hypersonic weapon performance have arisen from social processes by which the organizations developing these weapons construct erroneous technical facts favoring continued investment.”
The authors argue that hypersonics, as currently conceived, represent an evolutionary rather than revolutionary improvement over existing delivery systems. They use technical data and computer simulations to demonstrate that hypersonics do not travel at speeds in excess of already existing ballistic missiles, and are detectable for most of their flight paths by conventional means. Their analysis focuses mostly on boost glide vehicles and excludes hypersonic cruise missiles, which pose their own problems for air defenses but clearly do not constitute a transformative technological change.
To say hypersonics aren’t revolutionary is hardly to say that they’re irrelevant; the decision of the U.S. Navy, for example, to deploy hypersonic strike vehicles on its many destroyers is more akin to the deployment of sea-based ballistic missiles on surface ships than a truly transformative development. The prospect of hypersonic delivery vehicles emerging from multiple launch sites and approaching targets from unpredictable trajectories remains bad for crisis stability, even if the vehicles can be identified in flight and defended against. Still, the Tracy and Wright article is a useful corrective to the often breathless discussion of hypersonics in many contemporary accounts.