Would this be an application for SABRE? If this is only operating at 60,000ft then the SABRE would still be in air-breathing mode, although the performance would still be impressive.
I'm assuming cost is a factor, as is the readiness level of SABRE - I'm sure I've heard somewhere that the general principle is either a new airframe or new engine, not both at the same time. It would be very interesting though if REL launch an air-breathing only version of SABRE and managed to make it affordable enough to compete with conventional turbojets.
Either way, I'm glad that this is even happening alongside Skylon etc!
I'm assuming cost is a factor, as is the readiness level of SABRE - I'm sure I've heard somewhere that the general principle is either a new airframe or new engine, not both at the same time. It would be very interesting though if REL launch an air-breathing only version of SABRE and managed to make it affordable enough to compete with conventional turbojets.
Either way, I'm glad that this is even happening alongside Skylon etc!