[AR] Re: SpaceX
- From: Matthew JL <prmattjl@xxxxxxxxx>
- To: arocket@xxxxxxxxxxxxx
- Date: Thu, 29 Dec 2022 22:25:32 -0500
If you assemble from individually tested modules or solutions
your failures should be in detail progressing/testing and thus limited.
( IMU the Apollo programm worked a lot on that path.)
For what it’s worth this is general systems engineering in a nutshell.
That’s a major problem Starship has at a high level - it is a very tightly
coupled system that management cannot decouple, and the end result is
delays on delays as problems linearize.
Example: Just to get aerodynamic data the vehicles depended on tank
development, engine development, and GSE development. Delays on any one of
those caused delays for the whole test program - took almost a year to
resolve the kinks in manufacturing and GSE and get an engine in flight, and
a further year to get a satisfactory result with landing (which oddly was
not repeated).
A more general systems approach might have recycled existing hardware
(i.e., Merlin and F9 tank tooling) to produce a scaled down aerodynamic
test vehicle and prove out the handling characteristics while another team
resolved the tank welding issues and while yet another team brought
Raptor/GSE up to an acceptable level of reliability for an integrated
flight test.
Instead the program has largely ground to a standstill as immature elements
(Superheavy, the launch/catch tower and GSE) are becoming the pacing
items. It’s a great example of trying to put software dev principles into
hardware without fully understanding how to translate between the two.
On Thu, Dec 29, 2022 at 5:10 PM Uwe Klein <uwe@xxxxxxxxxxxxxxxxxxx> wrote:
Am 29.12.22 um 20:10 schrieb roxanna Mason:
True, "if you're not failing you're not progressing - fast enough".
depends.
If you are progessing with fullsize fullfunction samples that might be
the case. ( like SpaceShip, the run of major structural Ooopses ..)
If you assemble from individually tested modules or solutions
your failures should be in detail progressing/testing and thus limited.
( IMU the Apollo programm worked a lot on that path.)
in the end it is an optimax thing.
apropos: why did they weld the tanks together from rectangular sheets?
One Mr Mannesmann invented spiral welding using sheet tape ( or what is
the proper name for longer sheet metal bales?)
and it has been used in rocketry couple of decades ago already.
Uwe
--
Uwe Klein [mailto:uwe@xxxxxxxxxxxxxxxxxxx]
Habertwedt 1
D-24376 Groedersby b. Kappeln, GERMANY
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