https://www.bbc.co.uk/news/science-environment-47832920
UK engineers developing a novel propulsion system say their technology has passed another key milestone.
The Sabre air-breathing rocket engine is designed to drive space planes to orbit and take airliners around the world in just a few hours. To work, it needs to manage very high temperature airflows, and the team at
Reaction Engines Ltd has developed a heat-exchanger for the purpose.
This key element has just demonstrated an impressive level of performance. It has shown the ability to handle the simulated conditions of flying at more than three times the speed of sound. It did this by successfully quenching a 420C stream of gases in less than 1/20th of a second.
...
https://www.reactionengines.co.uk/ne...eat-conditions
In the recent tests, the compact precooler achieved all test objectives and achieved 1.5 MW of heat transfer, the equivalent to the energy demand of 1,000 homes; successfully cooling incoming air from a temperature at which hot steel starts to glow. The tests are the first phase in an extensive test programme which will see the precooler test article (HTX) exposed to high-temperature airflow conditions in excess of the 1,000°C (~1800°F) expected during Mach 5 hypersonic flight.
The significant testing milestone occurred at Reaction Engines’ recently commissioned TF2 test facility located at the Colorado Air and Space Port, US. The TF2 test facility has been constructed by Reaction Engines to undertake ground based ‘hot’ testing of its precooler technology. The technology has already passed an extensive range of tests in the UK where its performance was fully validated at ambient air temperatures.
They're apparently at Mach 3.3 conditions and ramping up to Mach 5 conditions and think it's all going better than expected so far.
https://www.reactionengines.co.uk/ap..._Animation.mp4