From: pgf@srl03.cacs.usl.edu ("Phil G. Fraering")
Newsgroups: sci.space
Subject: Re: DC vs. Shuttle capabilities
Date: 4 Jan 93 03:44:20 GMT
Article-I.D.: cs.C0B93G.Ksx.1
Distribution: sci
Organization: [via International Space University]
X-Added: Forwarded by Space Digest
Original-Sender: isu@VACATION.VENARI.CS.CMU.EDU

\2. There is limited experience with composite airframes in routine
/operational use.  Certainly less with composite cryo tanks, if that
\route is taken. (The exceptions to this lie in the B-2 program and the
/kitplane market, but the B-2 is very early in the flight programs. There
\may be some data from "black" programs that MacDac has access to.)

Actually, you forgot the F-22/F-23 program as well. And the F-20.
I would also note that the kitplane market bit seems to indicate
that composites are *better* understood than you think, and aren't
being used more widely because of stodgy industry. It sounds like
they're more innovative than Boeing/MacDac et al. Perhaps they are.
After all, who flew around the world unrefuelled first?

THANKFULLY _someone_ had the presence of mind to get Scaled Composites
involved on DC-X...

\3. The throttled RL-10 with nozzle extender is a new and essentially
/untried engine. Engine development is more art than science and has a
\history of being subject to delays.

I don't think so. There were no changes in any of the "wet" parts of
the engine, just the uncooled part of the nozzle. The stupid part
of the nozzle, as it were. If we can't do that, we should stay on
the ground.

\4. The servicing goals and rapid turnaround requirements of the vehicle
/are doable on paper, but have been held out as very risky by an
\independent study.

An independent study which apparently had an axe to grind of its own,
if you're talking about the TAC study.

\5. The weight margins on the vehicle are very tight, a historical source
/of problems in spacecraft and aircraft design.

Hmmph. Maybe you should repeat this a couple more times for the people
who started this, you'll help them make everyone else think it's true.

\Even given all that, the DC-X, DC-Y, DC-1 progression is a valid and
/prudent way to develop this class of vehicle.  There is one other source
\of risk that is hard to quantify at this point: MacDac is an ailing
/company, in substantial risk of major cutbacks.  Given that the company
\is throwing a lot of IR&D money into the project, it could founder on
/the rocks of a major financial crisis in the company.  I also give
\MacDac high marks for the management approach, which I have heard the
/project manager give a talk on.  It is modeled on the Lockheed "Skunk
\Works" approach.

I think people were saying the same thing about Apple at about the time
they were developing the Mac. Everyone was talking about how they were
going to lose out to IBM. But who's in financial trouble now?

Also, "we better not give them the project, they're a troubled
company" is the sort of self-fufilling prophecy that's kept many
many many good alternatives from being tried.

\Hopefully, the incoming administration will see the value of the
/vehicle, there will be a safe and successful flight test this summer and
\it will proceed with the DC-Y.  I consider the DC development program a
/prudent use of the government's risk capital.  However, we need to keep
\an eye on alternatives in case the DC program stubs its toe.

You say that as if DC isn't one of the alternatives instead of one of
the 200-million-a-year-on-design CAD queens.

\Edmund Hack - Lockheed Engineering & Sciences Co. - Houston, TX
/hack@aio.jsc.nasa.gov - I speak only for myself, unless blah, blah..
\"You know, I think we're all Bozos on this bus."
/"Detail Dress Circuits" "Belt: Above A, Below B" "Close B ClothesMode"

Phil Fraering          |"...Who in the valley shed the poison tear
pgf@srl02.cacs.usl.edu | no one knows
318/365-5418           | An old legend of a mythical hero..."
Newsgroups: sci.space