Skylon and SABRE: your questions answered

We had a fantastic response for our call for questions to the Reaction Engines team working on Skylon and its propulsion system, the SABRE engine. We collated your questions, sent them to Culham, and the RE team have kindly supplied answers. We’ll be continuing to cover Skylon, and hope to feature an update on the engine testing programme soon.

What additional technical challenges are presented by the deep cryo precooler tests, as opposed to the “warm” cryogenic tests that have been performed to date?
Suggested by Duncan Law-Green

To date over 200 pre-cooler test runs of varying purpose and duration have been undertaken, including sustained sub-zero operation of the pre-cooler for time periods in excess of six minutes. As part of this testing process we have had to address several technical challenges associated with the test rig (i.e. the equipment that we use to provide the pre-cooler with the desired operating conditions for a given test) but the pre-cooler itself continues to meet expectations and has proved to be robust. The items on the test rig equipment that have required rework were not meeting expectations due to the impact of the unique operating conditions, including very high pressures and very low temperatures.