SpaceX has been doing a lot of rebuilding and pad mods for the past
couple years (and will continue, with upcoming crew flights).
On 2018-02-17 14:24, William Claybaugh wrote:
Henry:
For launch vehicles, ops begin when it arrives at the launch site
(lands, for Shuttle; ferry flights are included in ops).
I’ve bundled the data here, but in some cases I also have a breakout
for “moves from processing to launch pad”. More efficient
vehicles obviously—in the data—minimize launch pad time.
Words have meaning: dry weight—in this case—means exactly that. No
propellant was included in the mass estimate.
I have no ops data on F9; I have counted cars at the launch site which
has not proven helpful: there are pretty consistently more cars at
that site than at ULA’s Atlas pad, go figure.
Bill
On Sat, Feb 17, 2018 at 3:09 PM Henry Vanderbilt
<hvanderbilt@xxxxxxxxxxxxxx> wrote:
Bill,
"Obviously incorrect" is overdoing the mea culpa. Too cryptic and
context-deficient, perhaps. A hazard of posting late and tired -
but
we've all done that at some point.
My apologies in turn for perhaps once or twice visibly enjoying
myself
too much during my guessing-what-you-might-mean responses. (Mind,
even
guessing wrong I found them useful; I hadn't revisited those numbers
in
too long.)
But now that you've posted that chart, there's obviously an
interesting
point here: Adjusting labor-hours per flight for overall vehicle dry
mass does lead to some interesting and instructive clusterings, and
potentially clarifies things in the search for factors affecting
vehicle
ops costs.
Though I do have two questions about your assumptions there:
- For expendables, where did you draw the line between
manufacturing
man-hours and support man-hours? The logical divide would be at the
point where the stages get delivered to the launch site and begin
pre-launch erection and processing. (Mind, on an expendable, I
could
see a defensible argument for counting manufacturing hours too.)
- For vehicles with fixed-size large solid boosters associated -
Titan
4, Ariane 5, Shuttle - did you include the dry mass of the solid
casings?
Hmm, make that three questions: What do you have on where Falcon 9
comes
down on this chart? You did mention some such. (And, where might
F9
reuse flights fit into that?)
Henry
On 2/17/2018 7:22 AM, William Claybaugh wrote:
All:attached
My sincere apologies for this obviously incorrect post.
There is a four order of magnitude difference in *Labor Intensity*
between subsonic aircraft and space launch systems (see the
chart), not in cost per pound.in some
By way of explanation (but not excuse), let me admit too putting
fairly long hours lately on this SSTO study and being in themiddle of
writing about labor costs when I dashed off this stupid post.about
My apologies to all,
Bill
On Fri, Feb 16, 2018 at 2:49 PM, William Claybaugh
<wclaybaugh2@xxxxxxxxx <mailto:wclaybaugh2@xxxxxxxxx>> wrote:
Henry:
To first order and to date, stuff that goes to orbit costs
four orders of magnitude more than subsonic stuff, per pound.that,
SpaceX has pulled about half an order of magnitude out of
leaving the difference—in their case only—at almostexactly four
orders of magnitude.<mailto:hvanderbilt@xxxxxxxxxxxxxx>> wrote:
Bill
On Fri, Feb 16, 2018 at 1:28 PM Henry Vanderbilt
<hvanderbilt@xxxxxxxxxxxxxx
higher
Cost-per-airframe/engine pound certainly scales up with
vehiclerelationship with raw
performance.
Development cost per project has a less linear
vehicle performance - other significant variables alsoapply.
achieving a
See my previous remarks about the different demands of
profitable performance increment over existingmature-technology
ailinergenerally avoid.
competition, versus developing a Good Enough version of a
radically new
space transport approach that inherently brings with it a
significant
performance edge.
And on the gripping hand, setting up for economic serial
production of
hundreds-to-thousands of copies of a big state-of-the-art
airliner is a
major expense that developers of advanced rockets
as
In fact, SpaceX's investment in reusability can be viewed
primarily aindustry)
way to support their high (for the old expendable
flight rateshelp
with a much smaller/cheaper booster core production
establishment than
they'd otherwise need.
To a first approximation, a successful Mark 1 version
fast-turnaround
SSTO space transport will not immediately require mass
production. More
like single digit numbers of hand-built copies.
Later marks, as the market radically expands, will be a
different story.
But the revenue from the early marks will be there to
supportfunding the
establishing higher-rate production. Not an issue for
initial push to market.much
Henry Vanderbilt
On 2/15/2018 3:15 PM, William Claybaugh wrote:
Rick:
Productivity gains in the aerospace sector have pretty
matchedestimate.
inflation over the period since the 747 was developed;accordingly, a
large passenger aircraft should cost—in today’sdollars—pretty much the
same as a 747 cost in then dollars. $1 Billion by your
aircraft is not
The other glaring issue here is that a subsonic
one tocomparable to a Mach 25 spaceship; trying to use the
estimate the<willsrw@xxxxxxxxx
cost of the other guarantees underestimating.
Bill
On Thu, Feb 15, 2018 at 1:42 PM Rick Wills
<mailto:willsrw@xxxxxxxxx>wrote:
<mailto:willsrw@xxxxxxxxx <mailto:willsrw@xxxxxxxxx>>>
vehicle
Henry
I'll throw my 2 cents in here.
$20B should be an upper limit for spaceplane/launch
reusabledevelopment. My estimate is $14B to $17B. A
orbitalto be 100%
launch vehicle may or not be an SSTO but it needs
spentreusable. My rational for the estimate is Boeing
$1 BillionToday,
to develop the 747 with first flight in 1969.
that's roughlycost;
$7B. Rough order of magnitude is double Boeing's
than addmight
20% for cost overruns. I can see why some people
argue $20B$30B
to $40B; Boeing Dreamliner is reported to have cost
to develop.reusable
However, SpaceX could hit 100% reusable with a
upper stage.and
On Monday afternoon, I spoke to freshman mechanical
aerospacethe
engineering students at the University of Dayton on
subject oflearned"
the Engineering Profession. In my "lessons
section, Iexample, I
discussed bias. Yep, we all got them. As an
discussedvehicle
my bias about what a reusable orbital launch
would like. Mybe
long held view was a reusable launch vehicle would
"aircraftpilot.
like": wings, landing gear, etc, and of course a
(fullfar
disclosure, I hold a commercial pilot rating and amengineer). In
preparing for the talk, I realize this bias when as
back as mySpaceship
childhood looking at Pratt & Coggins book "By
to thesolid for
Moon". It's 1950 technology but the science is
the time.off
In it, there is a nice drawing of a large wingedvehicle, they
called it a supply ship. The vehicle was taking
horizontallylooked
with a rocket powered sled. My five year old self
at thattechnical,
and thought, "that's neat". I now understand the
thesedevelopmental, political, and financial issues with
sorts ofNow
system configurations but the bias was implanted.
Space Xundamaged
comes along and shows how recovering an intact
first stageit's hard
can return a profit. Biases do die hard, but
to argue<mailto:arocket@xxxxxxxxxxxxx>
with success.<mailto:arocket-bounce@xxxxxxxxxxxxx>
Take Care and Be Safe,
Rick Wills
Still waiting for Buck Rogers
-----Original Message-----
From: arocket-bounce@xxxxxxxxxxxxx
<mailto:arocket-bounce@xxxxxxxxxxxxx<mailto:arocket-bounce@xxxxxxxxxxxxx>>
[mailto:arocket-bounce@xxxxxxxxxxxxx<mailto:arocket-bounce@xxxxxxxxxxxxx>
<mailto:arocket-bounce@xxxxxxxxxxxxx<mailto:arocket-bounce@xxxxxxxxxxxxx>>] On Behalf Of Henry
Vanderbilt
Sent: Thursday, February 15, 2018 1:54 PM
To: arocket@xxxxxxxxxxxxx
<mailto:arocket@xxxxxxxxxxxxx<mailto:arocket@xxxxxxxxxxxxx>>
technicallySubject: [AR] Re: SSTO fuels (was Re: SSTO)
On 2/13/2018 7:14 PM, William Claybaugh wrote:
> I have seen that paper. For something as
(much lesslittle
> economically) difficult as SSTO it seems a
light: even muchmuch
> more detailed analysis doesn’t often lead to
confidence that Ion one
> ought to recommend dropping $20 or $40 billion
solutionsomething
over another.transport is
My two cents worth: If fielding a useful SSTO space
costing you $20 to $40 billion, you're doing
very wrong.out to the
That's the sort of price tag you get by farming it
ofexisting cost-plus government aerospace houses,supervised by an
existing high-overhead government R&D bureaucracy.useful space
At the end of that process you may or may not get a
transport, but lots of people will have had decades
low-stressobjective -
white-collar job security. Fine if that's your
private teamtypically if you're a Congressman and they're yourconstituents - if
you actually care about building useful spacetransportation, not so
much.
Done as previously described, build your own
up doing
methodical risk-reduction then development (as withSpaceX and Blue)
it should be perhaps a tenth of that.
Henry V