Bear in mind, this project is a descendent of HOTOL, and thus has about 30 years of work behind it. Contrary to what some people seem to think, its not an few cool rendered movies and an engineering drawing.

Consider, for instance, that part of the motiavtion for beginning Skylon was because HOTOL had insurmountable engineering problems (crappy payload fraction, and a centre of mass whose motion would make the rocket dangerously unstable as its tanks emptied.) This is essentially a iteration of the air-breathing rocket plane design,

Hopefully, decades of paper simulation have spotted enough of the pitfalls that the hardware development won't turn up any major impediments to this being realised. ESA felt this was the case when they reviewed the projects, and if they thought this it was a non starter they would not have been shy about saying so.

The air intakes are closed on re-entry (and whenever else they aren't being used.) There is a cone shaped 'plug' at the front of each engine that can be used to vary the intake for different speeds/altitudes, or close it altogether.

He might be. Reaction Engines doesn't name its investors (or the ones who have pledged much larger sums of money, contingent on technology milestones like this precooler test being completed successfully

I agree, he won't put his brand on something this unready, but he might put his money into it.

People have been concerned about the possibility of a Clathrate gun for a while. Is this another potentially lethal feedback loop?

And if it fires, or has already fired, will we notice immediately?

You can wish all you like, but the Universe is not under any obligation to give you a neat solution.

The intelligent response is to be skeptical of anyone who comes out with some flashy bit of research claiming to have overturned the consensus. The moment you claim an entire field of natural science is suppressing some obvious insight, you are a conspiracy theorist.

"Interesting" for the same old knuckle-headed response that any resident of mount stupid gives whenever the phrase "dark matter" is mentioned? Clearly the mods are fellow mountaineers.

Dark matter is not a 'fudge factor' to make the sums work. Dark matter is an interesting component of the universe we are only just learning about. Anyone who sits there and thinks that dark matter only exists to make rotation curves work clearly understands nothing about astrophysics.

People who actually study this sort of thing don't find MOND to be "blasphemy" they find it to be "stupid".

The thing is, you've dismissed the dark matter theory (no, it doesn't need scare quotes) clearly without understanding it. You seem to be laboring under the delusion that rotation curves are the only evidence for this matter. They are not. Most aspects of large scale cosmology invoke dark matter in some way - and what is more, they do so in ways that cannot be predicted by your favorite hypothesis.

I suggest you actually learn some cosmology before making pronouncements on it, based purely on some wikipedia browsing.

Magic fairies pushing the stars around galaxies faster can be parametrized to explain rotation curves. You throw enough parameters at something, you are certain to get a solution.

There is more to it than that, and to be frank the 'alternative' theories are not good. To call the accepted theories 'populist' is, by the way, a red flag that you can kind of a crank.

This is a "hmm" results at best. What you have to understand is that this measurement is pretty local. They are very far from getting the big picture on this one despite being oversold in a press release.

Also, why rushing to break the consensus on dark matter might not be the best idea: http://edgepenguin.com/content/darkmatter.html

Sounds like Chinese whispers to me (pardon the pun.)

In any case, which Long March rockets is this (supposedly authoritative) guy allegedly talking about? The current ones, or the ones that are in development?

China's rocket fleet currently uses hypergolic propellants, which are expensive to buy, use, and clean up. Their next generation use LOx/RP-1 like sensible people, and will utilize the industrial base of modern China rather than legacy ICBM manufacturing from the 1970s.

I'm fairly skeptical of this claim.

I'm a physicist too.

The middle does spin, just not with such a great tangential velocity. Unless you have some kind of joint, at which point we are into the realm of some extremely tricky engineering (you want people on this station right? So how are you going to stop air getting out? Can you make this triply, quadruply redundant, like a good space system should be?)

And for what? Making something sci-fi like in LEO gets us not one iota closer to colonising Mars or any other world.

My point is, it isn't likely. More likely is a successful but unremarkable existence as a LEO launch service provider.

Launching satellites, and even manned spacecraft, IS just engineering. That is not meant in a dismissive way, by the way. I just object to the ideological spin (only a fraction of which emanates from Musk himself.

We are talking about manned spaceflight. I am well aware that SpaceX has attracted commercial clients for satellite launches; that you can make money putting communication satellites up is not news.

But their flagship program, the one that is being discussed here and touted as evidence that the glorious Invisible Hand will take us all to the stars, is what I am saying is completely dependent on NASA, and I'm, right.

Furthermore, the development of SpaceX launch technology, whilst commercial in its operation, would have been far more difficult or impossible without technological inheritance from NASA (e.g. pintle injector) and their support and facilities (remember where the first Falcon 9 was launched from...)

SpaceX is just an engineering company. They are a pretty decent one, so far. The fanboys (with a little subtle encouragement from Musk himself, unfortunately) are blowing them up to be a lot more than they are, and claiming that their Final Ideological Victory is at hand. It simply is not.