I wasn't blaming Bill, just pointing out that apparently Mike hadn't
understood the lesson.
On 4/4/20 2:09 PM, Henry Vanderbilt wrote:
Now, Rand. Blaming Mr. Griffin's later excesses on Bill hardly seems fair.
His excesses from back when they worked together, perhaps. And no, not who I'd first choose either, were I attempting argumentum ab auctoritate.
Henry
On 4/4/2020 11:51 AM, Rand Simberg wrote:
And then he came up with Constellation a decade later.
On 4/4/20 11:46 AM, William Claybaugh wrote:
Henry:
You really need to revisit your assumptions about me. Griffin and I proved that in 1994.
Bill
On Sat, Apr 4, 2020 at 12:44 PM Henry Vanderbilt <hvanderbilt@xxxxxxxxxxxxxx <mailto:hvanderbilt@xxxxxxxxxxxxxx>> wrote:
Ah! We agree that reuse is a benefit!
This is progress...
best
Henry
On 4/4/2020 11:21 AM, William Claybaugh wrote:
Henry:
Have it your way if you wish.
I am certain that Elon will tell you that the first benefit of
reuse is in spreading depreciation; and, that spreading
amortization is a very second order effect.
Bill
On Sat, Apr 4, 2020 at 12:10 PM Henry Vanderbilt
<hvanderbilt@xxxxxxxxxxxxxx
<mailto:hvanderbilt@xxxxxxxxxxxxxx>> wrote:
Bill,
Terminological quibbling aside, what I'm talking about is
something alien to the cost-plus trad space industry:
Commercial businesses ferociously controlling their costs,
both upfront and ongoing.
Up-front costs are like poison, while ongoing operating
costs are merely like heroin. Both are worth considerable
effort and ingenuity to minimize. And SpaceX, in
successfully going for reusability, has avoided both a big
initial chunk of poison and a fair-sized heroin habit, both
implicit in the trad cost-plus approach to eventually
flying circa sixty booster cores a year.
Given we once again seem to be talking past each other -
it's good to be back! - perhaps best we simply continue to
disagree about this being a significant part of why SpaceX
is cleaning the trad industry's clock.
cheers
Henry
On 3/24/2020 8:19 AM, William Claybaugh wrote:
Henry:
Terms matter: what you are talking about is depreciation,
not production savings.
I’m will to be educated but I would be shocked if making
1/5 as many vehicles resulted in a production system 1/5
the previous size: that is simply not how production works.
There are high fixed costs in any production line as well
as minimum costs.
Bill
On Tue, Mar 24, 2020 at 8:49 AM Henry Vanderbilt
<hvanderbilt@xxxxxxxxxxxxxx
<mailto:hvanderbilt@xxxxxxxxxxxxxx>> wrote:
Bill,
The long-term production difference in question, by
definition, is a factor of five times. Not 2:1 either
way around a base of 12/year.
SpaceX knew this going in. Being sensible people /not/
locked into the established way of doing things, they
likely would have set up a production establishment
for sixty expended cores a year very differently than
they did the plant for ~12 5X reused cores. Twelve a
year, as you say, is pretty much craft production -
modest production tooling and a lot of very skilled
hand labor, low plant investment but relatively high
ongoing personnel cost. 60X a year is still not
exactly Willow Run, but sensible people planning that
would very likely invest considerably more in plant
and tooling so as to not require5X the skilled
personnel plus 2nd and 3rd shift differentials,
working in
~2X the modest 12/year plant (assuming it was
originally run one-shift).
Yes, I oversimplified by saying "1/5th the size of
production establishment". Thought I'd allowed for
that sufficiently with "(to a first approximation)",
oh well. And yes, "size" was not quite the mot juste;
"cost" might have been closer to what I was driving at.
My basic point: SpaceX gambled on 5X reusability to
greatly reduce their up-front investment in, and
ongoing cost of, F9 booster production. And they seem
to have won. By a quick count, 92 F9 booster core
flights so far, and already over half of those (51)
have been used boosters. The used proportion will
only rise from here. And they did this on the
up-front investment for a dozen a year.
In other words, one of the reasons they're so far
ahead of the game now is they gambled and won bigtime
on a major-capital saving shortcut at the start. I
hope that's clearer.
Henry
On 3/23/2020 2:00 PM, William Claybaugh wrote:
Henry:
It isn’t clear to me that there is all that much
difference between making 12 per year and making 6 or
24.
One saves the material costs and the marginal labor
cost but the infrastructure doesn’t (or at least
shouldn’t) change much over that range of production.
That said, if you optimize your system for four units
per year you will find making 24 more costly than a
line optimized for twenty-four.
But rates of a few dozen per year—or a few
hundred—all fall into “craft production” and are not
going to show economically significant variation on
production costs. The benefit of even a few reuses
is in the depreciation of the hardware cost over
multiple launches.
Bill
On Mon, Mar 23, 2020 at 2:24 PM Henry Vanderbilt
<hvanderbilt@xxxxxxxxxxxxxx
<mailto:hvanderbilt@xxxxxxxxxxxxxx>> wrote:
Another way of looking at this that I think is
relevant: 5-reuse boosters allows SpaceX to
support a given flight rate with (to a first
approximation) 1/5th the size of production
establishment they'd need for fully expendable
operations.
Henry
On 3/23/2020 8:12 AM, William Claybaugh wrote:
Robert:
There is too little data to make any assertion
about stage longevity at this point.
However, ignoring propellant and launch
operations costs, five flights per booster would
indicate a cost per booster at 20% of the
manufactured cost, not including refurbishment
between flights. The former is around $30-35
million, so $6-7 Million per flight, again, not
including refurbishment. If an overhaul costs
more than about $6 million, it would make more
sense to simply build a new five launch lifetime
stage.
We may note that compared to a $50 million
price, these depreciated stage cost estimates
suggest either a good deal of profit or that
other costs (launch operations, refurbishment)
are high.
Bill
On Mon, Mar 23, 2020 at 8:51 AM Robert Steinke
<robert.steinke@xxxxxxxxx
<mailto:robert.steinke@xxxxxxxxx>> wrote:
From hobbyspace.com <http://hobbyspace.com>
about the latest Falcon 9 launch:
" A first stage engine shut down prematurely
(just before staging) but had no effect on
the mission as the other 8 engines made up
the difference. The booster also failed to
make a successful landing on a sea platform.
This was the fifth flight of this booster."
That was after a previous launch attempt
aborted due to slightly high power.
Wonderful demonstration of engine-out fault
tolerance, but it does look like the rocket
is showing some wear and tear after 5
flights. What does this do to their
economics if stages need an overhaul/have an
increased chance of loss of vehicle after
only 5 flights?
