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>> 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>] On Behalf Of Henry Vanderbilt
Sent: Thursday, February 15, 2018 1:54 PM
To: 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