starship-design: Re: Manufacturing Infrastructure

[KellySt@aol.com]

In a message dated 4/23/00 9:43:14 AM, lparker@cacaphony.net writes:

>> -----Original Message-----
>> From: KellySt@aol.com [mailto:KellySt@aol.com]
>> Sent: Saturday, April 22, 2000 8:55 PM
>> To: lparker@cacaphony.net; KellySt@aol.com;
>> starship-design@lists.uoregon.edu
>> Subject: Re: starship-design: FTL travel
>>
>>
>>
>> In a message dated 4/21/00 9:58:43 PM, lparker@cacaphony.net writes:
>>
>> >You still missed the point, if you are only building one of
>> the end product,
>> >it doesn't matter if you prefab it in sections and boost it
>> or boost it
>> >all
>> >at once.
>>
>> Well actually if you launch it in peaces its much more likely
>> to work right,
>> and not leak!
>
>I wasn't arguing the technical superiority or lack thereof, just the
>economics of mass production. As a mater of fact, in today's industry,
>QA is
>rather much of an after thought instead of an integral part of the
>manufacturing process. 

Depends on the company.  So put QA very high upand integral.


>> >However, if you have an industry that is mass producing engines for
>> >instance, it will be cheaper to use several of those engines
>> if necessary
>> >rather than building one special purpose engine to do the same job.
>>
>> Probably true, course that assumes your starship can use off
>> the shelf
>> engines.
>
>True, but let's look at a typical case. Rotary Rocket has a design for
>a
>MUCH better engine than any currently existing. However, due to time and
>budget constraints it made more sense to use the FasTRAC engine developed
>by
>NASA, which although better than existing engines, is still not as good
>as
>the one envisioned by Rotary Rocket.

Actualy I'm not sure if their engine would have been better, but it was 
mainly stockholder presure that drovre them to use NASA engine.  Investors 
could by everything else, but their whirling dirvish engine werided them out 
the door.


>It is adequate for their needs, available now, and CHEAPER. Most of those
>cost savings are because the FasTRAC engine is as close as it gets to a
>mass
>produced engine.
>
>> >It
>> >will
>> >be cheaper still if those engines are all being mass
>> produced in orbit
>> >from
>> >materials which are already in orbit rather than boosting ANY of the
>> >components from Earth.
>>
>> Thats a big asumption.  No reason to think a space built
>> peace of equipment
>> would be cheaper, likely to be more expensive.  Smaller
>> market and far
>> greater expenses for the space based manufacturing equipment
>> and personel.
>
>Well, since we haven't actually built ANYTHING in orbit, it is kind of
>hard
>to issue a blanket statement that it will be cheaper. I was basing that
>on
>several economic issues that are known - the cost of lifting raw materials
>or even not so raw ones out of Earth's gravity well chiefly. I was also
>assuming that the comparison was being made after the manufacturing facility
>was built.
>
>If we ignore the cost of the infrastructures of both groundside and
>space-borne facilities for the moment and simply compare the cost of the
>materials and delivery costs, it is FAR cheaper to obtain the materials
>in
>orbit than it is to deliver them to orbit. So much so that some economists
>are worrying already about what will happen to global market prices for
>precious metals when asteroid extraction gets into full gear.

That is your unwarented assumption.  Without know certain economic factors 
you can't tell is rawmaterials could be delivered to orbit cheaper then from 
Earth surface.  It VERY likely that it will be a long time before raw 
materials could be delivered cheaper to LEO, far far longer for manufactured 
goods.  After all, the earth is a FAR larger customer, and could expect much 
better economies of scale.  Obviously living expenses for the personel are 
less. etc.

I'm being so caefull to point this out, since its a unwarrented assumptin 
that many make.  The infamous (energy cost frol Luna to Leo being 1/20th as 
much as Earth to LEO being an obvious example.


>> >Yes, the infrastructure IS expensive. I stated that right up
>> front. But
>> >it
>> >is also paying it's own way. So the cost is amortized across
>> other projects
>> >besides just one interstellar craft.
>>
>> Are you sure its paying its way?  Unless there are a lot of
>> projects, you
>> could be costing more.
>
>Read the Commercial Space Transportation Study. It is all laid out and
>totaled up. Yes it would pay its own way, but even then it still requires
>that launch costs drop to $100/pound to LEO, and that is just for people
>and consumables!

Don't remember space factory complexes economics being discused in that one.  
Perhaps I'm thinking of another paper.

My concern is its a lot easier to lower launch costs to LEO then to lower 
manufacturing costs in LEO.  Also finding Markets in LEO is no cake walk.  
And deliving raw materials to LEO (in most any near future senerio) is a lot 
more expensive then delivering from earth to a Earth bound factory.  So a LEO 
factory would have a LOT of disadvantages.


>> I was refuring to reusables, obviously there can't be any
>> significant cost
>> savings with expendables!
>
>Sorry, but you were unclear...at least we agree!

True, sorry for confusion.

>> For those kinds of reductions, you need enough market to keep
>> fleets of such
>> vehicals very busy.  You are after all talking about reducing
>> cost to orbit
>> to costs simlar to trans ocean air frieght.  That takes similar sized
>> markets, or radically improved tech.  Some ae on the books,
>> but you need
>> massive launch requirements to run them at efficent enough rates.
>
>Also pointed out in the Commercial Space Transportation Study. And as Ben
>and Curtis figured out for themselves, it is a Catch-22 situation. We must
>have the industry in space to create sufficient demand for launchers to
>bring the cost down to the $100-$200/pound range, but the cost has to come
>down to that range first in order to make the industry possible!

Industries like tourism can start with higher cost tours for the select 
(despirate) few, then phase in lower cost later.  Geting from $1000 a pound 
to 100-200 with a RLV is mainly a fligh rate issue, and tourists could ramp 
up quickly enough to interest investors to fund the losses for a year or two. 
 Normal for most busnesses.

For our case however their is the lower costs for bulk cargo to consider.  
Systems like laser launchers, or tube launchers, are estimated at costing in 
the $10-$15 for large masses of cargo.


>> >> Now obviously your not going to want to lift millions to
>> >> hundreds of millions
>> >> of tons for a big starship if you could get it cheaper in
>> >> space.  But you
>> >> wouldn't want to life a thousand ton steel mill to make 40
>> >> tons of steel.
>> >
>> >Which is why I said LOTS of orbital industry paying it own
>> way doing other
>> >things. The steel for the interstellar probe becomes just
>> one more job,
>> >not
>> >THE job.
>>
>> Ok, then you need a market large enough to keep those
>> facilities that busy.
>
>Which brings me back to where all of this started, the optimum way to make
>a
>starship is in a space-borne shipyard that is making lots of ships with
>lots
>of experience in making all those ships, with lots of off-the-shelf
>components with proven life expectancies, etc. A situation that will only
>arise when there are several thousand to several hundred thousand people
>living and working in space to create that much demand in the first place!

Its not that simple.  You can't assume a starship manufactured in space would 
be that much cheaper then one made down here.  Now theproblem of launching a 
assembled Starship in one peace, or exceptably sized parst, could well be a 
show stoper.



>> Nice list, but it doesn't alter the major problem.  What can
>> you sell to
>> earth in enough volumn to pay for the operation of the platforms.
>
>If I knew the answer to that one, I would be very busy drumming up investors
>right now! I and lots of other people have studied this for years, and
>besides the catch already mentioned there are others. At the moment asteroid
>mining seems to be the only thing with real potential. Tourism is a dirty
>word to investors and all of the Space Access companies are careful to
>avoid
>using it when they talk to potential investors. I can't say I agree, but
>that seems to be the reality of it. Commercial communications has been
>the
>big driving force in launchers so far, but it really doesn't require the
>kind of presence needed, just launchers. There are lots of possibilities
>and
>most are detailed in the Commercial Space Transportation Study.

Some firms are talking about tourism, and some investors ae openly talking 
about funding such projects.  Don't know when/if they'll get together.

>Lee
>
>"Space isn't remote at all.  It's only an hour's drive away if your car
>could go straight upwards." - Sir Fred Hoyle

Like the sig.  ;)

Kelly