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:
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 attached chart), not in cost per pound.
By way of explanation (but not excuse), let me admit too putting in some fairly long hours lately on this SSTO study and being in the middle of writing about labor costs when I dashed off this stupid post.
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 about
four orders of magnitude more than subsonic stuff, per pound.
SpaceX has pulled about half an order of magnitude out of that,
leaving the difference—in their case only—at almost exactly four
orders of magnitude.
Bill
On Fri, Feb 16, 2018 at 1:28 PM Henry Vanderbilt
<hvanderbilt@xxxxxxxxxxxxxx <mailto:hvanderbilt@xxxxxxxxxxxxxx>> wrote:
Cost-per-airframe/engine pound certainly scales up with higher
vehicle
performance.
Development cost per project has a less linear relationship with raw
vehicle performance - other significant variables also apply.
See my previous remarks about the different demands of achieving a
profitable performance increment over existing mature-technology
ailiner
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 generally avoid.
In fact, SpaceX's investment in reusability can be viewed as
primarily a
way to support their high (for the old expendable industry)
flight rates
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 help
support
establishing higher-rate production. Not an issue for funding the
initial push to market.
Henry Vanderbilt
On 2/15/2018 3:15 PM, William Claybaugh wrote:
> Rick:
>
> Productivity gains in the aerospace sector have pretty much
matched
> inflation over the period since the 747 was developed;
accordingly, a
> large passenger aircraft should cost—in today’s
dollars—pretty much the
> same as a 747 cost in then dollars. $1 Billion by your estimate.
>
> The other glaring issue here is that a subsonic aircraft is not
> comparable to a Mach 25 spaceship; trying to use the one to
estimate the
> cost of the other guarantees underestimating.
>
> Bill
>
>
>
> On Thu, Feb 15, 2018 at 1:42 PM Rick Wills <willsrw@xxxxxxxxx
<mailto:willsrw@xxxxxxxxx>
> <mailto:willsrw@xxxxxxxxx <mailto:willsrw@xxxxxxxxx>>> wrote:
>
> Henry
>
> I'll throw my 2 cents in here.
>
> $20B should be an upper limit for spaceplane/launch vehicle
> development. My estimate is $14B to $17B. A reusable
orbital
> launch vehicle may or not be an SSTO but it needs to be 100%
> reusable. My rational for the estimate is Boeing spent
$1 Billion
> to develop the 747 with first flight in 1969. Today,
that's roughly
> $7B. Rough order of magnitude is double Boeing's cost;
than add
> 20% for cost overruns. I can see why some people might
argue $20B
> to $40B; Boeing Dreamliner is reported to have cost $30B
to develop.
> However, SpaceX could hit 100% reusable with a reusable
upper stage.
>
> On Monday afternoon, I spoke to freshman mechanical and
aerospace
> engineering students at the University of Dayton on the
subject of
> the Engineering Profession. In my "lessons learned"
section, I
> discussed bias. Yep, we all got them. As an example, I
discussed
> my bias about what a reusable orbital launch vehicle
would like. My
> long held view was a reusable launch vehicle would be
"aircraft
> like": wings, landing gear, etc, and of course a pilot. (full
> disclosure, I hold a commercial pilot rating and am
engineer). In
> preparing for the talk, I realize this bias when as far
back as my
> childhood looking at Pratt & Coggins book "By Spaceship
to the
> Moon". It's 1950 technology but the science is solid for
the time.
> In it, there is a nice drawing of a large winged
vehicle, they
> called it a supply ship. The vehicle was taking off
horizontally
> with a rocket powered sled. My five year old self looked
at that
> and thought, "that's neat". I now understand the technical,
> developmental, political, and financial issues with these
sorts of
> system configurations but the bias was implanted. Now
Space X
> comes along and shows how recovering an intact undamaged
first stage
> can return a profit. Biases do die hard, but it's hard
to argue
> with success.
>
> 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
<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 <mailto:arocket@xxxxxxxxxxxxx>>
> Subject: [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 technically
(much less
> > economically) difficult as SSTO it seems a little
light: even much
> > more detailed analysis doesn’t often lead to much
confidence that I
> > ought to recommend dropping $20 or $40 billion on one
solution
> over another.
>
> My two cents worth: If fielding a useful SSTO space
transport is
> costing you $20 to $40 billion, you're doing something
very wrong.
>
> That's the sort of price tag you get by farming it out to the
> existing cost-plus government aerospace houses,
supervised by an
> existing high-overhead government R&D bureaucracy.
>
> At the end of that process you may or may not get a
useful space
> transport, but lots of people will have had decades of
low-stress
> white-collar job security. Fine if that's your objective -
> typically if you're a Congressman and they're your
constituents - if
> you actually care about building useful space
transportation, not so
> much.
>
> Done as previously described, build your own private team
up doing
> methodical risk-reduction then development (as with
SpaceX and Blue)
> it should be perhaps a tenth of that.
>
> Henry V
>
>
>