One of the great advantages of the SABRE propulsion concept is that it is totally modular from both design and operational perspectives. This means in practice that all of the key parts in the engine can be developed and tested individually before being integrated into the rest of the machine. Applying this principle to the whole propulsion system itself, it becomes apparent that the complete engine ‘core’ can be tested at ground-level static conditions, right up to its operational design condition of Mach 5, and 25 km altitude. This is only possible because of the unique operational characteristics of the Pre-Cooler, which sits in front of the main engine core. The Pre-Cooler ensures the core sees cool ambient air conditions, right up to that high speed operating point. There is thus no need to test the SABRE core at actual Mach 5 conditions.
A major programme was launched in October 2016 to design, build and demonstrate a complete SABRE engine core, which is the whole engine minus the Pre-cooler and rocket nozzle (these systems are being developed separately). This Core design and development activity is a major undertaking, and will start delivering results in 2019, culminating in full system testing in 2020, at which point the world’s first air-breathing engine capable of accelerating from zero to Mach 5 will have been demonstrated.
Naturally this demonstrator engine has been designed at a scale that is totally representative of a SABRE flight engine and is completely consistent with the design of the new test facility, TF1 at Westcott.