Conventional Prompt Global Strike and Long-Range Ballistic Missiles: Background and Issues [January 8, 2019] [open pdf - 1MB]
"Members of Congress and Pentagon officials have placed a growing emphasis on U.S. programs to develop hypersonic weapons as a part of an effort to acquire the capability for the United States to launch attacks against targets around the world in under an hour. Hypersonic weapons can travel faster than Mach 5, or about 1 mile to 5 miles per second. This interest is driven by both the perceived mission need for conventional prompt strike systems and concerns about falling behind Russia and China in the development of these technologies. The United States is pursuing two key technologies for this purpose: boost-glide systems that place a hypersonic glider atop a ballistic missile booster or shorter-range rocket systems, and hypersonic cruise missiles that would use scramjet technologies. This report focuses, primarily, on the Pentagon's ongoing program to develop ballistic missilebased conventional prompt strike systems. This effort has been underway for about 15 years. The George W. Bush Administration demonstrated an interest in the use of conventional weapons for precision, long-range strike missions in the 2001 Nuclear Posture Review (NPR). This study called for the integration of precision conventional weapons with strategic nuclear forces in a new category of 'offensive strike' weapons. Several other Pentagon studies published during the Bush Administration also called on the United States to develop the capability to attack targets around the world, in under an hour, with conventional warheads."
CRS Report for Congress, R41464
Congressional Research Service: https://crsreports.congress.gov/