"We know it [the pre-cooler] can take debris, insects, leaves," Bond said.
Working with the U.S. military Bond estimates that the pre-cooler is now at a technology readiness level (TRL) of about 5. NASA and AFRL use a 1-to-9 TRL scale to describe a technology's stage of development. According to NASA's TRL descriptions, 5 represents "thorough testing" of a prototype in a "representative environment."
The AFRL work is being carried out under a Cooperative Research and Development Agreement (CRADA) with Reaction Engines that was announced in January. AFRL officials told Space.com that they are using computers to model SABRE.
"The Air Force research laboratories in the States have carried out some modeling to verify that the SABRE does actually work, that it is a real engine, and so I am hoping they are going to confirm that very soon," Bond said.
"This is obviously opening doors in the United States, and again, I can't say a great deal about that, but we have very good dialogue going across the Atlantic," he added. "In the next couple of years, it's going to be quite exciting."