4 ms·

Yeah, I've kept a close but unfortunately deeply skeptical eye on that technology. Seems that all the tolerances are razor thin and all the failure modes catast

Yeah, I've kept a close but unfortunately deeply skeptical eye on that technology. Seems that all the tolerances are razor thin and all the failure modes catastrophic. Like, water vapour in the pre-cooler tubes? This is waaay out there in engineering terms IMHO. Reading the recent heat exchanger news [1] the are very careful to talk about Mach 5 airflow temperatures, not velocity. Surely it the product of these two that produce the mind-boggling heat flux that the pre-cooler is tasked with cooling. It feels like they're going to keep carving out smaller and smaller targets until they run out of money. [1] https://reactionengines.co.uk/reaction-engines-test-programme-fully-validates-precooler-at-hypersonic-heat-conditions/ https://reactionengines.co.uk/reaction-engines-test-programm...

panick21_ 5y ago
If you look at the cost the calculated originally for the Skylon, it doesn't actually beat Falcon 9 even. And when I listened to some presentation with the people involved, it seem they had no real understanding of some of the complexity involved. Their history is mostly in academic and British space industry, and all the project they worked on before are canceled paper studies that were kicked around in Britain. When asked about the structure of Skylon the answer was vague hand waving about some new materials that might exist. Nothing at all concrete that has even begun being tested for high complexity air frames and high requirements. Elon himself was asked about this when he presented in Britain. And he answered by saying that investing massive amount of complexity in the easiest part of your flight was counter productive. Pushing the thrust of your traditional rocket engine a little bit higher, is far, far easier then engines. And if you are really optimizing to that kind of extreme, doing even more advanced version of second stage engines and structural optimization on the second stage would likely always have a higher pay off per complexity invested.
- DrBazza 5y ago
  SpaceX vs Skylon/Sabre, feels a bit like the Henry Ford quote about "faster horses". I do appreciate the scale of the engineering problems and neither is easy, but SpaceX and rocketry just seems like another "faster horse", whereas Skylon/Sabre is something totally new. But I don't have much hope given how long it's taken to get to where we are now. It's the space equivalent of tech - get to market first with something that works, not something that's a tech tour-de-force.

panick21_ 5y ago

If you look at the cost the calculated originally for the Skylon, it doesn't actually beat Falcon 9 even. And when I listened to some presentation with the people involved, it seem they had no real understanding of some of the complexity involved. Their history is mostly in academic and British space industry, and all the project they worked on before are canceled paper studies that were kicked around in Britain. When asked about the structure of Skylon the answer was vague hand waving about some new materials that might exist. Nothing at all concrete that has even begun being tested for high complexity air frames and high requirements. Elon himself was asked about this when he presented in Britain. And he answered by saying that investing massive amount of complexity in the easiest part of your flight was counter productive. Pushing the thrust of your traditional rocket engine a little bit higher, is far, far easier then engines. And if you are really optimizing to that kind of extreme, doing even more advanced version of second stage engines and structural optimization on the second stage would likely always have a higher pay off per complexity invested.

DrBazza 5y ago
SpaceX vs Skylon/Sabre, feels a bit like the Henry Ford quote about "faster horses". I do appreciate the scale of the engineering problems and neither is easy, but SpaceX and rocketry just seems like another "faster horse", whereas Skylon/Sabre is something totally new. But I don't have much hope given how long it's taken to get to where we are now. It's the space equivalent of tech - get to market first with something that works, not something that's a tech tour-de-force.