To improve its testing of scramjet engines, the Air Force may reopen Sandusky, Ohio's Hypersonic Test Facility (HTF) at the NASA Neil A. Armstrong Test Facility--known as Plum Brook Station until 2020. An example of such an engine is the one Northrop Grumman [NOC] is building for the Air Force's future Hypersonic Attack Cruise Missile by RTX [RTX]. HTF had its origins in the mid-1960s when NASA established the Hot Hydrogen Test Facility for high temperature analysis of nuclear propulsion…