Hypersonic Missiles

The write-up

Mach 5 isn't the new part. Maneuvering is. Ballistic missiles fly that fast too; hypersonic weapons can change course.

1. Exhibit A

   Two kinds

   Hypersonic weapons fly at Mach 5 or faster. Boost-glide weapons release a maneuverable glide vehicle from a rocket booster, and hypersonic cruise missiles use air-breathing scramjet engines.

2. Exhibit B

   Speed isn't the difference

   Missiles with ballistic warheads also reach Mach 5, about a mile per second. The key difference is that a glide vehicle can maneuver and change course after release, often on a flatter, lower path.

3. Exhibit C

   Detection

   Because of line-of-sight limits, most ground-based radars can't see a hypersonic weapon until late in its flight, leaving little time to launch interceptors.

4. Exhibit D

   Survivability debate

   CBO concluded that hypersonic missiles probably wouldn't be more survivable than ballistic missiles with maneuverable warheads, unless the ballistic missiles faced highly effective long-range defenses. CRS notes that critics say the weapons lack defined mission requirements.

5. Exhibit E

   Heat

   GAO says the exterior can exceed 2,000 °F. CBO cites sustained temperatures as high as 3,000 °F, which require extensive flight testing.

6. Exhibit F

   Who has them

   Russia reportedly fielded its first hypersonic weapons in December 2019, and China likely did as early as 2020. The U.S. Defense Department requested $3.9 billion for hypersonic weapons in FY2026, down from $6.9 billion in FY2025.