Since the last flight of the15 years ago, plenty of aerospace companies have been trying to keep the dream of faster-than-sound flight alive in one way or another.
One of those firms, UK-based Reaction Engines, got a boost Thursday when Boeing, Rolls-Royce and BAE Systems invested £26.5 million (about $37.4 million) in its hybrid aircraft engine that would operate both as a super-fast jet and a space-bound rocket.
Still in development, the SABRE engine would breathe air at lower altitudes for a top speed of around Mach 5 (generally, hypersonic flight is at least five times the speed of sound), but then switch to a Mach 25 rocket mode when it reaches thinner altitudes at the edge of space.
Set for ground testing by 2020, SABRE (it stands for Synergetic Air-Breathing Rocket Engine) could be used in several ways, including powering hypersonic passenger airliners and reusable space vehicles and launching satellites into orbit.
In its press release, Boeing's investment arm, HorizonX, didn't state how it might use SABRE, except that it expects "to leverage the revolutionary technology to support Boeing's pursuit of hypersonic flight." Rolls-Royce, which makes conventional subsonic jet engines in addition to cars, was equally cagey, saying it plans "to incorporate this technology into future products."