> -Original Message-
> From: [EMAIL PROTECTED] [mailto:[EMAIL PROTECTED] On
> Behalf Of hkhenson
> Sent: Wednesday, April 16, 2008 8:10 PM
> To: brin-l@mccmedia.com
> Subject: An interesting response
>
> At 12:00 PM 4/16/2008, Dan M wrote:
> >(Keith wrote)
> > >
> > > At 12:00 PM 4/11/2008, Dan M wrote:
> > >
> > > (Keith wrote)
> > > > >Takes 10 200 ton payload
> > > > > rockets each flying once a day to do it and with a blank check
> > > > > perhaps under 5 years to work up to this production rate and 6-7
> > > > > years from start to get to a $50 billion a year revenue stream
> > > > > increasing at $25 billion a year.
> > > >
> > > >OK, let's do the math on that. At the present time, the cost of lift
> to
> > > >geosynchronous orbit is $20,000 per kg or $20M per metric ton. Ten
> 200
> > > ton
> > > >payloads would be about 40 billion per day or 14.6 trillion per year.
> > > >That's roughly the GDP of the US.
> > >
> > > And the analogy would be how impossible it is to build a dam sending
> > > all the contents in Fed Ex envelopes.
> > >
> > > >The trick is, as it always has been, to lower launch costs.
> > > Unfortunately,
> > > >even in inflation adjusted dollars, launch costs haven't dropped much
> > > over
> > > >the past 40 years.
> > >
> > > I agree with you. The question is why?
> >
> >I wrote a blog on that general topic at the Scientific American website
> >
> >http://science-community.sciam.com/blog-entry/Dan-Ms-Blog/Unfortunate-
> Promin
> >ent-Misconception-Concerning-Tech/34870
>
> It was an interesting blog, though *social problems* are in a very
> different class than engineering ones like going to the moon. At
> least they are now. Ask and I will point you to a dark story about
> how they might be solved.
>
> >The essence is that when the engineering community starts working on
> >something, it starts working on the obviously solvable problems first.
> >Then, progress slows as the easy problems are solved and harder problems
> are
> >faced. The point at which this happens, and the manner in which it
> happens
> >is based on what is found. The speed of sound barrier is rather
> >significant, and we have not found a way to develop efficient planes that
> go
> >at Mach 1.1 almost 60 years after we first went above Mach 1.
> >
> > >It's not the cost of energy.
> >
> >No, it's the cost of the system.
> >
> > >A nearly hundred percent efficient space
> > >elevator lifts about 2400 mt a day (on less than a GW)
>
> snip
>
> >I've invented a few things that are used worldwide and am still engaged
> in
> >practical science/engineering. I've worked close to guys who's
> inventions
> >have reduce world costs for producing oil by about 250 million/day.
>
> Since there are around 80 million barrels a day produced, that's a
> reduction of about 3%.
>
> >So, I
> >think I'm fairly familiar with processes that are economical and that
> work.
> >I have not seen anything in what you have written on this subject that
> gives
> >an indication of an understanding of the nature of practical solutions to
> >problems.
>
> What do you want? The current 747 cost about $300 million and dry
> masses out to about 185 mt or $1.6 million a ton. Produced in
> similar tonnage, do you see any reason these rockets would cost more
> than per ton than a 747? If so, why?
For the rocket itself, not counting all the other expenses associated with
launches, that's not an unreasonable cost.
> First and second stage mass 619 tons, (third stage is mostly power
> sat parts) so if they cost on a par with a 747, they would cost just
> a hair over a billion each, with one coming off the production line
> every 20 days, or about 31 mt a day. That might sound like a lot,
> but I have worked in a locomotive factory that made 30 times that
> much a day in product (8-9 locomotives a day at 113 mt each). At
> peak production 747s were coming off the line at a slightly higher
> tonnage per year. If you use them for 200 flights the capital cost
> per flight is $5 million /200,000kg or $25/kg.
Here's where you throw in the unspecified assumption. A simple disposable
rocket, like the ones being used by all launch facilities but the shuttle,
could cost about what you said. But, then you talk about reusable rockets
and assume that the initial capital cost is the critical factor.
The fantasy of the space shuttle was that it could be reused easily. 10
years into the mission, it was supposed to require a very small ground crew,
getting lift costs to near earth orbit down to about $25/kg or some such
number. But, the maintenance is very high and expensive. The shuttle costs
a lot of money to fly, even though we are not buying new shuttles, the big
fuel tank is the cheapest part of the assembly, and the solid fuel rockets
are recoverable.
So, I've seen no estimates for this, just the same arm waving I heard about
the shuttle years ago. I can think of Russia, Japan, the EU, the US, and
China all having si
