Within the next year, the U.S. Air Force plans to unveil novel spacecraft concepts that would be powered by a potentially revolutionary reusable engine designed for a private space plane.
Since January 2014, the Air Force Research Laboratory (AFRL) has been developing hypersonic vehicle concepts that use the Synergetic Air-Breathing Rocket Engine (SABRE), which was invented by England-based Reaction Engines Ltd. and would propel the company's
Skylon space plane.
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The key SABRE technologies that AFRL, based in Ohio, will start work on later this year, and possibly fly in the future, are related to the engine's precooler. This device precools the air entering the engine at speeds greater than four times the
speed of sound (Mach 4). SABRE's precooler will cool such air from more than 1,832 degrees Fahrenheit (1,000 degrees Celsius) down to minus 238 F (minus 150 C) in one one-hundredth of a second. The oxygen in the chilled air will become liquid in the process.