Bill,
And you've never disputed the matter with me or anyone else here since?
Okay...
best
Henry
On 4/4/2020 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?
