Hypersonics: tests and hype

The Navy is starting a new hypersonic program built for the launch cells many U.S. warships already carry, not just a few modified destroyers. (onr.navy.mil) Hypersonic flight starts above Mach 5, or five times the speed of sound, and the engineering problem is heat as much as speed. A boost-glide weapon uses a rocket booster first, then releases a glide body that rides the atmosphere toward its target. (nasa.gov) (britannica.com) (dote.osd.mil) The new effort is called Flight Advancement of Structures for Hypersonics, or FLASH. In an April 2026 solicitation, the Office of Naval Research said FLASH will design, build and flight-test prototype vehicles for a “surface-launched, tactical range” strike capability compatible with the Vertical Launch System and the Virginia Payload Module used on submarines. (onr.navy.mil) The launch-cell detail is the point. The Mk 41 Vertical Launch System has been in Navy service since 1986 and is installed across the cruiser and destroyer force, including Arleigh Burke-class ships. (navy.mil) (usni.org) That is a different path from the Navy’s current Conventional Prompt Strike weapon. The Pentagon’s 2025 test report says CPS uses a two-stage booster and Common Hypersonic Glide Body, with fielding planned first on Zumwalt-class destroyers in fiscal 2027 and later on Virginia-class submarines. (dote.osd.mil) The Navy cleared a major CPS milestone on May 2, 2025, when it announced a successful end-to-end flight test using its cold-gas sea-launch approach. That method ejects the missile clear of the ship before the first-stage motor ignites. (war.gov) FLASH is framed more narrowly and more cheaply. The Office of Naval Research said the program will focus on structural performance, aerodynamics, thermal protection, controllability and affordability, and it is explicitly asking industry for options in high-temperature structures, thermal protection systems and flight-test demonstration capability. (onr.navy.mil) Public discussion of hypersonics often runs ahead of what officials actually say. A YouTube video posted April 20, 2026, claims a U.S. “hypersonic jet” broke long-standing speed limits from a regular runway, while YouTube also labels the video with a notice that “sound or visuals were significantly edited or digitally generated.” (youtube.com) The Navy’s own documents are much more specific than that genre of video. They describe prototype testing, compatibility with existing launch hardware, and a tactical-range boost-glide concept meant to widen deployment beyond the three-ship Zumwalt class. (onr.navy.mil) (dote.osd.mil) So the near-term story is not a mystery aircraft or a record sprint. It is a Navy procurement and engineering bet that a smaller boost-glide weapon can fit the launchers already sitting below deck on much of the fleet. (onr.navy.mil) (navy.mil)