How much of a future do you think the Skylon project has? A couple of friends in the aerospace industry have told me they think SpaceX will effectively "win" now that they can land the Falcon. Are they too optimistic about SpaceX?
Which, as it turned out, was anything but trivial and took 14 years. Their main competitors – ULA and Arianespace – already announced they won't be able to manage similar capabilities this decade; and their plans for the next decade are still not as sophisticated as SpaceX's approach (they only want to recover the engines and build a wholly new stage around them).
Skylon is a massively more ambitious undertaking compared to that – if it works, it'll be the first practical SSTO, the first horizontal takeoff spaceplane, the first vehicle to use multi-mode engines, the first practical space plane to use a novel heat shield technology, …
That's an awful lot of challenges to tackle. If it turns out to work, and if it then turns out to be as re-usable as hoped (something that did never panned out for the Shuttle, and which SpaceX will only learn over the next years for their Falcon), then it could beat SpaceX… in a decade or two.
The main advantage Skylon would have over the Falcon 9 is the fact that the Falcon 9 is not fully reusable because they don't and can't recover the second stage, while the entire Skylon is recovered.
That's significant, of course. The second stage makes up about 25% the cost of the rocket, so that places a ceiling of about 75% on how much Falcon 9 reusability can save..
But then, starting from where the Falcon 9 is now, building a new rocket that can also recover the second stage doesn't seem too difficult. It's a big challenge, to be sure, but relative to Skylon it's not too bad.
Skylon is certainly much more ambitious in terms of how it works, but it doesn't seem to be very ambitious in terms of what it can do, which is not a promising combination.
Plus, payload fraction is another thing like SSTO, horizontal takeoff, novel heat shields, and all the rest that are cool but just don't matter except for how they affect the end result. All that matters in the end is how much you can launch, and how much it costs.
That's the critical point. Skylon is still vaporware, and they've really assumed the best case in published numbers.
So, afterwards, it needs another 8000 m/s Δv on rocket engines to reach LEO.
Skylon is a neat trick, but it's not magical.
NASA on the other hand had lot's of issues.
Challenger: "[W]e're only qualified to 40 degrees ...'what business does anyone even have thinking about 18 degrees, we're in no man's land.'"[2]
Columbia had 27 successful missions and went though several redesigns one of which resulted in failure.
How, when the cost was limited by the refurbishing costs after each launch?
https://en.wikipedia.org/wiki/STS-61-B Had a 54 day turnaround time which is not 'great' still. That's 6+ short missions per year per orbiter call it 5 including missions and some unscheduled down time.
They started with 6 orbiters * 5 missions a year ~= 30 missions per year. The shuttle actually did 135 over 30 years or 4.5 per year * (~0.75 per orbiter per year).
PS: At even 1/2 that 30 mission per year rate they would have finished 135 missions in under 10 years.
If your engines burn out after 5 instead of the planned 55 flights, I damn well hope you're going to invest into more R&D on them!
> Had a 54 day turnaround time which is not 'great' still.
And the pressure to keep up that break-neck pace directly led to the Challenger disaster.
Still, the point is they did not need to wait over a year reusing launches from design constraints. Instead, NASA simply did not need that many manned launches per year.
Now, I am not saying it was a great or even that good of a design. It was simply a poor fit for what they used it for. NASA would have been better off with either a much smaller shuttle that only sent crew up, or an unmanned system for hauling cargo. Instead, they tried to do both which caused a lot of problems.