On 21/06/2011 7:55 AM, Matt wrote:
Skylon, cool as it is, has shown nothing to indicate it has solved the
classic SSTO problem: when you get into building actual hardware and
the design gets toward CDR, the payload mass faction drops rapidly to
zero. There has to be some technological breakthrough to make this
succeed in SSTO while being affordable to build, and I don't see it.

The breakthrough is the SABRE engine.

Sylvia.