🚀 go-pugleaf

In <1992Dec29.202546.12526@aio.jsc.nasa.gov> hack@arabia.uucp (Edmund Hack) writes:

>1. The B-777 is one in a series of airliners built by the same
>engineering organization.  No one has built a man-rated space vehicle
>with the design goals of the DC-1 project, and certainly not at MacDac.

No one has ever built an airplane with exactly the same specifics
as the 777 before, either.  Not even Boeing.  You assume that, for
some reason, an aircraft capable of reaching orbit is harder to
build than a 777.  But you can't say why.

BTW, the Boeing 777 is man-, woman-, and child-rated.


>2. There is limited experience with composite airframes in routine
>operational use.  

Really?  I bet the Rutan brothers would be surprised to hear that.


>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 think the 777 will use engines, too.  Airbreathers, in fact.  Potentially
much more troublesome than a simple rocket.


>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.

Ee, gads!  An independent study!  Well, boys, I guess that settles it.
Don't you believe everything you see in black and white?


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

The weight margins are probably tighter on the 777.  It can tolerate
more weight growth and still fly, but if it loses too much of its
payload capacity, no one will buy it.