The United States, Russia and China are developing hypersonic boost-glide vehicles. A simple model of their trajectory is developed by assuming that the vehicle does not oscillate during the transition to equilibrium gliding. This model is used to analyze U.S. Department of Defense data on test flights for the Hypersonic Technology Vehicle-2. This glider's lift-to-drag ratio—a key performance parameter—is estimated to be 2.6. The model is also used to calculate the tactical warning time that a boost-glide attack would afford an adversary. Other aspects of boost-glide weapons’ military effectiveness are explored. Approximate calculations suggest that, compared to existing non-nuclear weapons, boost-glide weapons could penetrate more deeply but would be less effective at destroying silos. The distance at which a boost-glide weapon armed with a particle dispersion warhead could destroy a mobile missile is also calculated; it is expected to be significantly larger than for an explosive warhead....

This article was originally published in Science & Global Security. A supplement to the article can be found here