In article ers.net,
says...

The development has so far been low-cost (about $20 million), but to
make a real Skylon spaceplane the company has said it would need $12
billion!!! Let me put it this way: it will never happen.

People seem to forget the political dimension. The French will never
allow EU money to be used for a British spaceplane, they want to keep
all space-based development in France. Germany is
currently fighting France tooth and nail over the work on the new
Ariane-6, the Germans want at least 50% of the new rocket to be German.
Other EU countries are only allowed to pick up the crumbs
off the floor. How long before these nations start to clamor about this
and demand a much greater role in the rocket's design and production?

The only hope Britain has of seeing the Skylon become a reality is to
team up with the Americans. There's little chance of that succeeding
since U.S. politicians don't like their nation's space
transportation systems being based on foreign tech.

The US is already spending its billions on SLS, which keeps spending
flowing to all the right congressional districts, which is exactly what
US politics dictates. Because of this, from a political point of view,
SLS will be successful even if it never flies. My bet is that it will
fly, but will be too expensive to fly (on average) much more than once
or twice a year.

From a technical point of view, it's too bad that SLS is nothing more
than a warmed over shuttle derived launch vehicle which does little to
nothing to advance the state of the art in reusable launch vehicle
hardware.

:-(

Jeff
--
"the perennial claim that hypersonic airbreathing propulsion would
magically make space launch cheaper is nonsense -- LOX is much cheaper
than advanced airbreathing engines, and so are the tanks to put it in
and the extra thrust to carry it." - Henry Spencer