ALEXANDRIA, Va., April 15 -- United States Patent no. 12,601,314, issued on April 14.
"Reusable upper stage rocket" was invented by Andrew Lapsa (Seattle) and Thomas Feldman (Kent, Wash.).
According to the abstract* released by the U.S. Patent & Trademark Office: "A reusable upper stage rocket or other atmospheric re-entry vehicle includes a nose, a base opposite the nose, and a propulsion engine toward the base. The propulsion engine includes a high pressure chamber and a nozzle configured to exhaust gas generated by the high pressure chamber. The nozzle includes an initial nozzle portion, a secondary nozzle portion downstream of the initial nozzle portion, and a nozzle exit at a downstream end of the secondary nozzle portion. The second...