"Len" wrote in message
oups.com...
Pete:

Actually, we are not in disagreement with respect to the value,
importance, appropriateness, and timing of conceptual design
versus building something that should never have gotten past
the drawing board/tube.

Having said that, I am currently extremely enthused about our
last two (unpublished) design iterations. If either of these pan
out and live up to my current expectations, then, yes, with
funding, I would be ready to commit to preliminary design,
component testing, followed by prototype detailed design,
fabrication, flight test and initial operation as an operational
prototype based upon one of these new (related) concepts. True,
any design can always be improved (the Wright Brothers
should never have flown until they had a better design).
However, a space transport can be far from perfect and still
clobber the existing way of doing business. Dutch Kindleberger
used to say that at some point you have to shoot the engineer.

Indeed. When it comes time to move beyond the drawing board, engineers
that can not move beyond the drawing board need to be shot... Inability
to cut a design off and let it bleed, (as my wife would say), can be
indicative of too long a design cycle. Some make the mistake of leaping
in and bending metal before they are ready, others make the mistake of
not experimenting enough during the design process because they do not
know how to bend metal.

I find that decisions of bending metal verse more conceptual design are
usually obvious and make themselves, so long as the homework has been
done. When the development path of least resistance becomes to bend
metal, then you know it is time to start bending metal. It sounds very
promising that you have reached such a point.

My reply to Derek's post stems from two emotions:

1) Strong feelings that parallel yours with respect to the
importance of conceptual design and the need for far more
emphasis on conceptual design instead rushing ahead to
build another "white elephant." I have said for many years
that the most important technology of all is system-level
conceptual design--which should be done in many heads
in as decentralized manner as possible. There is no such
thing as "duplication," when it comes to system-level
conceptual design and R&D in general. The tendency of
the bureaucracy to force R&D into planned categories is
folly and very destructive. The best system-level conceptual
design depends only on better packaging of component things
we already know how to do; and this should be open to as
many individuals and companies as possible.

It has always seemed to me with regard to space transports that while
there was considerable clever detailed design, no one really knew what
they should be designing for. Probably because design was always a one
off affair and so they never had the opportunity to learn what really
mattered. Kludgy design speaks volumes, a design should speak with
clarity of purpose. It is as if there has been a lack of singular
individuals directly forging such coherent purpose into space transport
designs.

I would still have to say that I do not think there is a current rocket
engine within the right design range let alone a well developed one.
This is not to say that current engines are not workable, just that no
engine has really hit the spot yet. Specifically, a low cost, reliable,
easy to use engine with high ISP and much higher T/W. While not
necessary, such an engine would significantly ease the development of
space transports. Such rocket engine metal bending is long overdue.

2) My basic agreement with Derek that, at some point, we
need to get on with the show--coupled with my current excitement
over our latest conceptual designs.

Sounds like you are ready. I know that my own thoughts on space
transport design are still bouncing around quite a bit, though I am
starting to get some general design and development principles in place.

Stand by for further (conceptual) definition of these latest
ideas. Perhaps realistic reevaluation will dampen this latest
excitement. But right now, it looks "breakthrough good."
If and when it continues to look good, I'll publish the new
concepts on our web site and let others critique them.

I am looking forward to it. :-)

Pete.