JF Mezei wrote:

On 2017-10-27 18:49, Greg (Strider) Moore wrote:

Actually delivers? They've done 15 flights this year and expect at least 4
more (I'm not counting Heavy as I expect that will slip).


What percentage were re-used stage 1s ?


Enough to service all customers asking for them.


Consider commercial aircraft. There is a huge difference between
building the couple of prototypes to do flight tests and going into
production and ramping up production. The prototypes get a lot more
"manual" work to get things to fit/work. But to go into production all
those production glitches need to be fixed otherwise they can't ramp up
production since each plane takes too long to assemble.


The 'used' boosters are the same as the new ones, so all the
'prototype' **** was done long ago. There is very little 'automated
assembly' in aerospace in general and even less when it comes to
rocket boosters.


SpaceX is basically at the "prototype" stage for reflying stages. It
hasn't delivered yet on high rate and quick turn around of reflying stages.


Name a customer who has asked for a 'used' stage and hasn't gotten
one. You don't fly payloads worth hundreds of millions of dollars on
'prototypes', you nitwit.


Just because everyone has confidence that it will deliver, it doesn't
mean that it has delivered.


Also not clear what percentage of landings might cause more than a
easily replaced broken leg (compressed crush zone). Say, for sake of
discussion, only 50% of stages can be reflown, this could change SpaceX
plans to wind down Falcon 9 production to start BFR production because
they would need higher stock of new Falcon 9s to cope with fact they
aren't recyling 100% of stages.


Say, for sake of discussion, that each used stage must be bathed in
magic pixie dust produced by rainbow unicorn farts. It makes about as
much sense as what you're saying. A compressed crush zone is NOT a
"broken leg". This has been explained to you repeatedly, but in true
Mayfly fashion it doesn't seem to stick in your brain for more than a
very short time. Let me try again. The emergency crush core on
Falcon 9 landing legs is there for when the landing is so 'hot' that
the leg would take damage from the impact. In this case, the crush
core, well, crushes and absorbs all that energy. The leg itself is
unlikely to take damage unless the entire crush core is expended,
which has NEVER happened. The crush core is a cartridge that is
designed to be easily inspected, removed, and replaced as needed.

Just what else do you think is being 'damaged' in your 50% 'for
discussion' catastrophic damage rate?


So there needs to be more empirical data on landings, refurbishements
before SpaceX would know for sure how thing will pan out.


You will never think there is enough 'empirical data' to draw a
conclusion because you insist on nitwittery.


or it could be that even with the hard landings, the stages are far from
having any structural damage and fixing legs is the only repair needed,
so it become more of a 1 and 0 (either it lands and can be re-used
easily, or goes kaboom on landing).


Which is where it's at. Just what 'structural damage' do you think
can occur when the energy absorbing crush core hasn't been fully
crushed?


And while "going kaboom" on landing hasn't happened in a while, is this
just stroke of luck, or has SpaceX realy gotten their software to work
reliably enough to conclude that "kabooms" won't happen again? How many
more landings before such a conclusion can be made?


It's rocketry, you nitwit. A 'kaboom' is always possible. Musk said
(back at the beginning of 2016) that he expected about a 70% success
rate with recovery in 2016 (actual rate was 63% and one more success
would have taken it to 75%) when recovery was still billed as
'experimental' and 90% in 2017 (so far it's 100%) when recovery is
considered 'production'. Developmental tests of the capability were
performed in 2014-2015, including both water landings and some barge
attempts. Experimental test was conducted in 2016. 'Production' use
started at the beginning of 2017. Success rate through experimental
test and production use is 19 attempts for 14 successes (just under
74%) with all the failures occurring during the experimental test
phase. That's a pretty damned good record when it comes to rocket
testing.

Musk seems to think he has enough data to declare it 'production use'
starting at the beginning of this year. I believe him before I belief
**** you pull out of your ass.


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