[island911]

Nah.

Perhaps a bridge too dangerous or too expensive (pick one)

SS1 made it a couple times with one pilot.

And, of course, the many space men of decades past hwho have gone much further.

A Ramble on materials: rocketplanes of the past used super high-end metal alloys (Inconel, Titainium..) Here, Burt Rutan's company, Scaled Composites, has had lots of success with composites for regular planes ... but does this scale well to the brutal environment of Maching into the mesosphere? Are composites the best choice here? ... or simply the old adage of When the only tool you have is a hammer, every problem becomes a nail. ?

I will note that CF has some great structural stability handling sharp thermal gradients, but.... seems, at best, they are not using enough of it.