--- In spacesettlers 10980, Ian Woollard wrote:
> If the shuttle were actually to launch 50 times a year,
> there's every reason to think it would be much cheaper
> than even the 5th or 6th flight (due to economies of
> scale and better utilisation of the launch pads etc.)

OK. Let's assume 50 launches per year (and this is unlikely since it
needs good weather not only at the launch site, but simultaneously at
multiple abort landing fields), for 30 years = 1,500 launches. Let's
also assume that the non-marginal costs are no higher (e.g. no
investment in efficiency infrastructure that should make the marginal
costs go down) than the actual 2010-projected $174 billion.
http://en.wikipedia.org/wiki/Space_Shuttle_program#Costs

Let's also assume the Wikipedia-sourced marginal cost of $60 million
per launch. $60 million per launch * 1500 launches = $90 billion that
gets added to the existing $174 billion program cost. That brings us
to a new total of $264 billion for the program. Dividing that among
the 1500 launches leaves a cost of $176 million per launch, or
$3,520/lb of payload (if each payload size is 50,000 lbs).

That misses the $50/lb target by 70 times. It also assumes that the
program does not pause for assessment when mission-failures (e.g.
Challenger, Columbia) happen. If we figure 2% mission failure, our
cost/lb should go up by at least 2%. Therefore, $3,520/lb of payload
becomes $3,590/lb. We might have to pay for replacement Orbiters and
solid-rocket booster-pairs when they blow up, too, which might add
another $100 billion or so to the total program cost. And then there
is the cost for the value of the 30 lost payloads. Maybe each payload
we blew up was worth $500 million * 30 payloads = $15 billion.

That would bring us to $379 billion / (1500 - 30) launches = $258,000
per launch. That would be about $5,200/lb of payload, and miss our
$50 target price by over 100 times.

Admittedly, the boosters would scale better if they were liquid-
fueled instead of solid-fueled. The up-front costs would be higher,
though, which was one reason that Congress decided against funding
the liquid-fueled option.

> So the Shuttle was always a bad idea, but in an alternative
> universe where somebody had actually managed to find a
> reason d'etre it might have worked... maybe.

It is important that Gerard O'Neil and the L5 Society were banking on
the Shuttle achieving economies of scale substantially better than
the $5,200/lb we find above:
http://www.google.com/search?q=shuttle+neill+princeton+voodoo

"The detailed calculations of feasibility cranked out by O'Neill's
institute at Princeton had been based on NASA's wildly optimistic
estimates of the cost of launching material into space using the
space shuttle."

In 18/10/2008, hitssquad wrote:
> --- In spacesettlers 10980, Ian Woollard wrote:
>> If the shuttle were actually to launch 50 times a year,
>> there's every reason to think it would be much cheaper
>> than even the 5th or 6th flight (due to economies of
>> scale and better utilisation of the launch pads etc.)
>
> OK. Let's assume 50 launches per year (and this is unlikely since it
> needs good weather not only at the launch site, but simultaneously at
> multiple abort landing fields), for 30 years = 1,500 launches. Let's
> also assume that the non-marginal costs are no higher (e.g. no
> investment in efficiency infrastructure that should make the marginal
> costs go down) than the actual 2010-projected $174 billion.
> http://en.wikipedia.org/wiki/Space_Shuttle_program#Costs
>
> Let's also assume the Wikipedia-sourced marginal cost of $60 million
> per launch. $60 million per launch * 1500 launches = $90 billion that
> gets added to the existing $174 billion program cost.

You're double counting, because you haven't taken off the costs of the
shuttles that did launch. You're also not allowing for economies of
scale on the increased production run (about 3x cheaper).

> That misses the $50/lb target by 70 times.

The number I have is $118... in 1970s dollars, but your above numbers
are in a mixture of dollars.

You're just not calculating it right. They did miss, but not as badly
as you imply.

--
-Ian Woollard

We live in an imperfectly imperfect world. Life in a perfectly
imperfect world would be much better.