JF Mezei wrote:

On 2016-06-19 11:45, Fred J. McCall wrote:

Non sequitur. Go back and read what I said.

Your assumptions are based on sending the barge to a failed landing and
refurbiushing it after the explosion being minimal costs.


I note that when called on a non sequitur response, your 'answer' is
to start snipping out context. Cost of sending the barge is DIESEL
FUEL. That's pretty much down in the noise. Have you LOOKED at one
of these barges? Just what do you think there is for an explosion to
damage? There are two cargo containers with 'support equipment'.
That's it.


My statement is that only accountants know this now. They have
experience in how much it costs to run the barge and support ship, and
they have had a few crashes to know what sort of damage is involved and
how many man hours/equipment this costs.


A lot of these numbers are public or easily inferred.


Elon Musk in an interveiw a while back even admitted that they don't yet
have all the numbers and enough data points to know whether refurbishing
will be good business.


The expectation is that they won't have to 'refurbish' anything. Just
inspect and refly.


Note that yesterday, he tweeted that he now expects 70% of landings to
be succesful. But IF those statistics were broken down to 95% of
ISS/LEO meissions being succesful and only 30% of GTO missions being
successful, you can see that this would affect whether they bother
trying to recover GTO missions to begin with.


Why?


I am not stating that they should or shouldn't bother. What I am saying
is that they need to have statistics on how each type of mission affects
recovery chances and run the numbers to see if this is a paying
proposition in the long term.

(and to get those numbers, they have to try as many landings as possible
which is what they are doing now.) Hopefully it does turn out that the
costs are low enough and success rate is high enough that they try to
recover all of them. But they don't have enough numbers yet, and since
the software is still evolving, the cutover between reliable landing and
unreliable landing is also moving to include more "reliable" landings.


Well, doh!


Falcon 9 isn't a 'paper bird'. It's flying hardware.

The landing part is still very much R&D. And the refurbishing of the
stage 1 is also R&D.


Non sequitur. But you cut all the context.

The idea is that you don't need to 'refurbish' the stages. You do a
quick inspection and then refly them.


--
"Ignorance is preferable to error, and he is less remote from the
truth who believes nothing than he who believes what is wrong."
-- Thomas Jefferson