From the Document: "The U.S. Department of Defense is pursuing two types of hypersonic weapons technologies: boost-glide systems that place a maneuverable glide vehicle atop a ballistic missile or rocket booster, and cruise missiles that would use high-speed, air-breathing engines known as scramjets to travel to hypersonic speeds. This In Focus addresses only the first of these technologies. The Pentagon's FY2021 budget request for hypersonicrelated research is $3.2 billion--up from $2.6 billion in the FY2020 request--including $206.8 million for hypersonic defense programs. This increased funding and statements from Pentagon officials demonstrate growing support for weapons that could attack priority targets promptly and with improved accuracy without facing defeat by an adversary's air or missile defense systems. Pentagon officials have also expressed concerns about advances in hypersonic weapons technologies in Russia and China, and on the potential threats to U.S. forces, allies, and territory."
CRS Report for Congress, IF11459
Congressional Research Service: https://crsreports.congress.gov/