Brin-l Digest, Vol 377, Issue 3

[Dan M]

> -----Original Message-----
> From: brin-l-bounces at mccmedia.com [mailto:brin-l-bounces at mccmedia.com] On
> Behalf Of hkhenson
> Sent: Thursday, April 17, 2008 4:03 PM
> To: brin-l at mccmedia.com
> Subject: Re: Brin-l Digest, Vol 377, Issue 3
> 
> At 12:00 PM 4/17/2008, Dan M wrote:
> (Keith wrote)
> >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. 
> 
> Agreement!

Right, but that's for the rocket itself.  Not a shuttle, a rocket. 

> > > The .pdf was recommended as a good reference by Hu Davis of Eagle
> > > Engineering.  Look him up.
> >
> >What has he built?
> 
> The Eagle as in "the Eagle has landed."

OK, I asked because I've seen so many "experts" who never had to do things.
He does have great experience leading successful space design teams.  So, I
looked up the website of the space company he and Buzz Aldrin are leading

http://www.spaceandtech.com/spacedata/rlvs/starbooster_sum.shtml


>From my perspective, this shows the difficulties inherent in reusable craft.
He is not discussing a rocket that can hit near orbit, launch a system to
geocentric orbit, and then re-enter the atmosphere.  Rather, he is
presenting a far more modest goal: salvaging the first stage of a present
system.

The cost of doing this is 32 tons extra weight that is carried throughout
the first stage.  If you want, I think I can calculate the decrease in
payload that results from this, but I know it's not insignificant (what I'd
do is cut the weight of the upper stages by this amount and cut the payload
proportionally.)  

I'm not faulting him for this.  I think it reflects the modest goals that
are realistic.  I looked at the links from this website and noted that the
X-33 was the furthest along of all the reusable near orbit systems:

http://en.wikipedia.org/wiki/Lockheed_Martin_X-33


I Googled for reusable orbital vehicles and found SpaceX's Falcon one as the
one that's furthest along.  The Falcon 1 has a first stage that is designed
to parachute down to earth and be reusable.  Later versions are suppose to
have stages that can reach orbit and re-enter the atmosphere.

http://en.wikipedia.org/wiki/SpaceX

As of two years ago, the owner has spent 100M of his own money, and has had
two failed launches.  The first one was fairly spectacular, but the second
one was a guidance failure at the end of the mission.  He hopes for Air
Force contracts if the third one (with a small Air Force payload) succeeds.

But, he was also quoted as saying  

"If we have three consecutive failures [.] it's not clear to me that we know
what we're doing and maybe we should go out of business."

So, I consider him at the razors edge.  As you know, I can cite a number of
programs that have failed in developing reusable orbital vehicles.

I think a recoverable, reworkable first stage, with a parachute drop and an
ocean retrieval, might be workable....and save some money in the long run.
But, re-entry is an extremely harsh environment.  

Right now, besides NASA and the US Air Force, there are five groups that can
provide launch capacity (Russia, the EU, Japan, China, and India).  None of
them, as far as I can see, are going towards reusable orbital vehicles.
Given the problems NASA has had, given the failure of the X-33, a prudent
person would consider such a task difficult and expensive in the present
environment.  

So, the step which I strongly disagree with is assuming that such a vehicle
can be built for the cost of a disposable rocket. 

 
> No, that *is* the capital cost. I just have not discussed operating
> and maintenance costs which I have not estimated.  This design uses
> 49 SSME in it and they are only expected to last 40 flights.  How
> much labor is it going to take to pull 40 engines out of the first
> stage and 9 out of the second stage every 40 flights?  On average
> they would be changing out 12 a day so they should get good at
> it.  What's the closest model we have for airline operations?  Or for
> that matter, railroad operations?  A SSME has got to weigh less than
> a locomotive engine!

That's not where the biggest problems have been for NASA.  Maintaining the
heat shield has been a nightmare for NASA.  


> If you were flying them every day instead of ever 100 days could you
> do it with the same number of people?

They were suppose to fly once a week...with far fewer people than are needed
to fly them once every 100 days. 

 
> Part of the cost is the very low production rate for spare
> parts.  Another big chunk is paper pushing.  

NASA is inefficient, I won't argue with that.  But, the fundamental problems
remain.  If it were easy, don't you think one of 7 non-NASA groups would
have done something by now?
> 
> Some years ago I read that the effort to recover and refurbish the
> segments cost more than just letting them sink.

> 
> 2000 tons per day is an entirely different model.  You can't apply
> much of what we know about government space programs to it.

But, in areas where costs have dropped like a rock (e.g. computers, big
screen flat panel TVs, etc., we've seen a pattern of price drops funded by
the early implementers.  Right now, launching commercial satellites is a
multi-billion dollar industry.  A simple 30% price drop for the same
reliability would be a big deal.  

Compare the last 40 years of prices with rockets with the last 5 with gene
splicing and gene "glueing" equipment.  The former price has been stable,
even though multiple players are in the market.  The latter price is falling
a factor of two every year with no real end to this pattern in sight.  I
look for empirical evidence like this to predict the near future.  It isn't
perfect, but it does better than following futurologists. 
 
> 
> What gives you the idea space is harsh?  Now a wind generator
> standing in salt water, that's harsh.

I was referring to my own work.  Oil platforms have stood in salt water for
generations.  Sea water is not very corrosive.  I've had to design for far
worse environments.

My own experience has been with MWD (Measurement While Drilling). Our
standard qualification test is temperature to 175C, 20 g RMS random
vibration for 2 hours in each of the three axis, and 1500 g shock.  With
that random vibration one does get the 3 sigma 60 g vibration from time to
time.

Our equipment runs to 25k psi, and must pass the torque of the drillsting.
Wear is obviously an issue, with rotation rates up to 250 rpm and
penetration rates approaching 600 feet/hour.  We do fail; we had a
catastrophic failure on one well where the drilling resonances were
unbelievable.  A bolt tightened with 15,000 foot-lbs of torque backed out
during drilling from the vibration.  But, we have been able to get sensitive
crystals and electronics to last many hours in this environment.  Our best
achievement was getting the electronics boards to go from 1500 to 13,000
downhole hours between failures.

 
> 
> When power sats are not considered (and they usually are not) then
> you get statements like this:
> 
> "No combination of renewable energy systems have the potential to
> generate more than a fraction of the power now being generated
> by fossil fuels."
>    -- Jay Hanson

Nuclear power is a green alternative that's already price competitive
(unless PC demands raise the price artificially).


> http://www.drmillslmu.com/peakoil.htm

The first peak oil prediction that I read was from the 1920s. There was one
in the '60s, and of course one in '82. One of these times, it will happen,
but only when there is a cost effective alternative.

he feel around the oil patch is that the present price is unsupportable. A
buddy of mine, who got his MBA from Baylor is in a neat program where the
alumni get to talk with top economists.  He talked to one of last years
Nobel prize winners (one of the two Americans....sorry I forgot the name)
who thinks the base price for oil is $50.

I'd guess $75, because of the fall of the dollar, but with the big Brazil
find....and the fact that two countries with tremendous reserves (Venezuela
and Iraq) are marginal producers for political reasons.

 
> It would surprise me if there were any physical state humans left on
> the planet by 2100.  

OK....I take it that you think that AI will come soon.  I think AI will come
about the same time the Left Behind series becomes factual. :-)

> 
> Please don't unless you have some idea that's not been talked about
> before.  What I would like is a critical discussion leading to a
> model for a pipeline to GEO large enough to build power sats in large
> numbers at low enough prices to deliver power at the ground bus bars
> at a penny a kWh.  If we can do that, we can make synthetic gasoline
> for a dollar a gallon.  If we can't, several billion people are
> likely to die in the toboggan ride down the back side of peak oil.

Why do you think mainstream science is wrong on global warming?  Why do you
think people will willingly die before using nuclear power?

Dan M.