SpaceX is betting on technological stagnation

This isn't exactly a new thought, but I don't think I've ever consciously framed it in just these words before. As we've observed before, SpaceX is making real and important advances, but it is incremental  progress built on technology that is, at its core, over a half century old.

Not only was SpaceX never really the disruptor it was billed as; its position depends on no real disruptor entering the industry. Now it may be facing two, and if both should come through, it is not entirely clear how much of a niche would be left between them.

It is difficult to know for certain how much progress those Russian engineers are making on nuclear rockets, work on a workable spaceplane seems to be moving along at a nice pace.

Not only would Sabre power units enable rapid, point-to-point transport inside the atmosphere, but they would also allow reusable vehicles to make the jump straight to orbit without the need for multiple propellant stages - as is the case now with conventional rockets.

Sabre would work like an air-breathing jet engine from standstill to about Mach 5.5 (5.5 times the speed of sound) and then transition to a rocket mode at high altitude, going at 25 times the speed of sound to get into space, if this is the chosen destination.
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The essential innovations include a compact pre-cooler heat-exchanger that can take an incoming airstream in the region of 1,000C and cool it to -150C in less than 1/100th of a second.

REL proved the pre-cooler's efficiency at taking an ambient air stream to low temperature in 2012. Now it must do the same in a very high-temperature regime. This is the purpose of the Colorado tests.

"To have a very high-temperature, high-volume flow of air to test the pre-cooler - we needed a new facility. That is now complete," explains Shaun Driscoll, REL's programmes director

"We will be running tests in the next month or two. We will be using re-heated aero engines to drive air through the system. We will drive air into the pre-cooler at up to 1,000C."
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REL is a private venture with the backing of aerospace giants BAE Systems, Rolls-Royce and Boeing. It has also received significant R&D support from the UK government. Esa's propulsion specialists act as technical auditors, assessing each step in the development of the Sabre concept.