JF Mezei wrote:

On 2016-09-02 20:07, Rick Jones wrote:

Perhaps, but SpaceX's history to date hasn't suggested they want to
have two versions of the Falcon 9 going at the same time.

Depends on definition of "man rated". If it requires things are
properly tested before manned flight,


It sort of does, but not what you're thinking of.


... then it makes sense to implement
changes/improvements on cargo rockets first and once they have flown
enough, you then implement those changes to man rated rockets.


No, it doesn't. You don't seem to understand that engineering is not
just "let's cobble a bit and see what happens".


This is more of a logistics issue than one of keeping 2 models in
production.


Except you only have the 'logistics problem' because you are keeping 2
models in production.


You build your V1.2 rockets for cargo, but keep parts to build a V1.1
for manned flight, but after V1.2 has flown enough, manned flighst use
V1.2 as well. So it is a staggered impememntation instead of keeping 2
models.


You can't define away the fact that you are talking about keeping two
models in production.


Also, with re-usability, SpaceX will have to deal with inventory of
stage1s of different versions. So it has to deal with those logistics
anyways.


Well, no, it doesn't.



In fact,
their payload user's guide touts how the Falcon 9 is going to be even
safer for customer payloads because it has been built around the idea
of man-rating the launcher.


The design may have all the features needed for man rated flight, but if
the design is constantly tweaked to improve it, then this introduces
uncertainties for launch (as with those tank struts that caused
catastrophe last year).


Which part of the following statement is it that is confusing to you?

THEY DON'T CONSTANTLY TWEAK THE ****ING ROCKETS!!!!!!!!!!

You make changes in 'blocks', not rocket by rocket. If you're
constantly mucking about with the rocket, how do you ever establish
the reliability of the thing? Every ****ing one is different under
your scheme. NOBODY does that ****. We don't do it with airplanes,
either.



information) kept showing the launch dates of various customers
slipping, and the way things continue to seem to slip (even prior to
this recent anomaly) suggests that anyone currently a SpaceX customer
isn't worrying much about schedules. Yet anyway.


Customers can't do much but wait. It isn't as if they can go to Wendys
if the lineup at McDonalds is too long. Their satellite is designed for
launch on a specific rocket (structural attachments etc) and it will
take longer to book on new launcher and modify satellite for it.


Well, actually they can, if the delay is long enough.


If you're liuanching a new GPS satellite, and you already have 30 in
orbits that work, a delay isn't a big deal. But if you have already
started to sell internet to a remote community and your sattelite is
delayed by a year, then you have problems. Different customers have
different needs and priorities.


Only a huckster like Mook would sell something he doesn't have.


--
"Some people get lost in thought because it's such unfamiliar
territory."
--G. Behn