Tempest flies like a plane, then dives and navigates underwater like a submarine, on a single pressure-rated airframe. The mission that needed two vehicles and a coordination layer now needs one.
U.S. Indo-Pacific Command is fielding expendable autonomous systems across every domain of contested water. As operations push past the First Island Chain, the undersea picture degrades exactly when it matters most. Holding it demands persistent, attritable sensing that can reach denied water and operate below the surface.
Tempest launches vertically, covers distance at fixed-wing cruise speed, submerges under control, traverses below the surface, then surfaces and returns to flight. One operator, one asset, no mid-mission handoff and no multi-vehicle coordination.
The mission set maps directly onto how expeditionary and special-operations units already work the near-shore: a repositionable sensor picket one day, a loitering undersea munition or one-way strike asset the next, a rapid amphibious search-and-rescue tool when it's needed.
FY2026 is the first year the Pentagon carries a dedicated autonomy line, a structural shift in acquisition rather than a one-time spike. Inside a $13.4B total, the undersea slice is the beachhead.
Small unmanned aircraft have reshaped how forces find, fix, and strike. Undersea vehicles are following the same proliferation curve. The littoral is where those two trends converge, and operating there demands an asset that can cross the surface on demand.