Hypersonic Weapons: Vulnerability to Missile Defenses and Comparison to MaRVs

Assessing the utility of hypersonic boost glide vehicles (BGVs) requires comparing their capabilities to alternative systems that could carry out the same missions, particularly given the technical difficulties and additional costs of developing BGVs compared to more established technologies. This paper discusses the primary motivations given for BGVs-most notably countering missile defenses-and summarizes current hypersonic development programs. It finds that evading the most capable current endo-atmospheric defenses requires that BGVs maintain speeds significantly higher than Mach 5 throughout their glide phase, which has implications for their mass and range. The paper then compares BGVs to maneuverable reentry vehicles (MaRVs) carried on ballistic missiles flown on depressed trajectories and shows that MaRVs can offer significant advantages over BGVs in a wide range of cases. Finally, the paper shows that BGV maneuvering during its glide phase can result in substantial costs in range and glide speed.