Remember VenurStar? http://www.fas.org/spp/guide/usa/launch/x-33.htm It
was built by Skunkworks in the late 1990s. The project was canceled after
the propulsion tank failed the test. The tank had to have very complex
shape because it had to fit with in the airframe that resemble flattened
cone. To cut weight, they had to used Graphite composite. The Graphite
composite simply didn't work too well at the liquid Hydrogen temperature.
I mean they had to push the envelop of technology in every area to achieve
single stage to orbit. To date we don't have the material to build such
space ship.

The most efficient single stage vehicle ever built was in 1960s. It was
Atlas. It had 1% throw weight and the tank was made out of .030 inch
stainless steel. Unless the tank was filled with fuel or pressurized the
whole thing would crumple down to scrap metal!

Emilio

"Walt BJ" wrote in message
om...
The real seemingly inescapable problem (I haven't seen an answer in
some fifty years) is that all the real sharp 'Skunkworks' types retire
or get elbowed aside by career bureaucrats whose main thrust in life
is never having to make a single-handed decision, because it might be
wrong and oops there goes the career. Better to place the action in
the hands of a committee (share the blame), wait for someone else to
stick their neck out, or temporize (wait) and hope the problem goes
away or is overtaken by events. In the meantime relie on dubious
statistics to show the problem really isn't that serious in the first
place. Both Shuttle losses can be attributed to this kind of thinking.
- "It's only a few degrees colder . . ."
- "We haven't had any problems with pieces of foam so far . . .
A personnel staffing problem that needs fixing - the question remains
- how? Mybe private industry could do it, but the bean-counters and
short-term bottom-line thinking from the Harvard Business School
eventually killed the Skunkworks . . .
Walt BJ