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  #11  
Old May 9th 05, 05:48 PM
Ed Kyle
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Rand Simberg wrote:
On Mon, 09 May 2005 04:49:24 GMT, in a place far, far away, Scott
Lowther made the phosphor on my
monitor glow in such a way as to indicate that:

Shuttle is currently about $400M per launch.


That's not a meaningful number. Marginal cost is much less, and
average cost is much more, at expected flight rates.

Shuttle-C or similar would not be more.


It would be if the launch rate is lower.


Right.

Take the number of people employed building, training,
stacking, launching, recovering, and refurbishing a
launch system, multiply that by $100K, then multiply
that result by about 2-3 or so, and you get a rough
estimate of the total costs of running the launch
program for one year. At low launch rates - which
is what NASA human launch systems are always going
to operate at, this cost won't vary much with the
number of launches. The best way to cut costs is to
reduce the number of workers.

The current shuttle budget is about $4.5 billion per
year, which translates to $750 million per launch if
there are six launches in a year, or $1.125 billion
per if there are four launches, or $4.5 billion per
launch if there is one flight, etc. But note that
this is the combined launch and mission costs, which
includes feed and care of astronauts, cleaning the
shuttle toilet, processing the payloads, etc.. It's
not that much when you consider that Titan IV Milstar
missions (for an unmanned communications satellite -
no astronauts to care for) cost more than $1 billion
each.

So to get the costs for a shuttle-derived system down
to something reasonable - say $400 million per flight
at four launches per year - NASA would have to establish
a program that only employed around 6,500 (total, for
everything from factory to control center to parking
lot security, etc). This is only about one-third of the
total currently involved in the space shuttle program.
(Or it could employ the same number of workers at 1/3rd
the pay.)

- Ed Kyle

  #12  
Old May 9th 05, 06:11 PM
Ed Kyle
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Ed Kyle wrote:

So to get the costs for a shuttle-derived system down
to something reasonable - say $400 million per flight
at four launches per year - NASA would have to establish
a program that only employed around 6,500 (total, for
everything from factory to control center to parking
lot security, etc). This is only about one-third of the
total currently involved in the space shuttle program.
(Or it could employ the same number of workers at 1/3rd
the pay.)


Or NASA could do something remarkable and design
CEV to fly atop existing EELV assets. If four
launches were to occur each year, then the EELV
production rate would be increased from 8 to 12
annually and the per-flight launch services cost
would drop from about $120 million to $80 million
(a bit of guessing). Then, if NASA could consolidate
centers, shut down Complex 39, and run the vehicle
and mission part of the program with only 2,000
workers or so (complementing the 3,800 or so who
build and fly the EELVs), the entire CEV program
could be run for maybe $1 billion per year ($250
million per flight).

It won't happen.

- Ed Kyle

  #13  
Old May 9th 05, 07:03 PM
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Ed Kyle wrote:

Or NASA could do something remarkable and design
CEV to fly atop existing EELV assets.

....
It won't happen.


The astronaut corp apparently desperately hopes not. The hydrogen fire
on Delta IV scared the bejeesus out of everyone who saw it; DIV cannot
fulfill the CEV mission without solid-rocket strapons (up to 7, if
memory serves), thus negating the already dubious safety superiority to
solids; and the DIV has to fly an odd trajectory (due to structural
concerns) that means that there are points in the ascent when abort is
*not* survivable. Atlas V heavy is a bit of an unknown, but apprently
has a number of the same performance issues.

  #14  
Old May 9th 05, 07:17 PM
Pat Flannery
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Ed Kyle wrote:


So to get the costs for a shuttle-derived system down
to something reasonable - say $400 million per flight
at four launches per year - NASA would have to establish
a program that only employed around 6,500 (total, for
everything from factory to control center to parking
lot security, etc). This is only about one-third of the
total currently involved in the space shuttle program.
(Or it could employ the same number of workers at 1/3rd
the pay.)


Is there any breakdown regarding how many of those are related to
orbiter inspection, TPS repair, and SSME (I assume that the cargo
version wouldn't use SSMEs, but rather expendable RS-68s for the sake of
economy and system simplicity) postflight checkout and maintenance?
Also if we go over to a unmanned system, we don't have to meet the
stringent requirements for SRB safety, so we can probably reuse more SRB
segments.

Pat
  #15  
Old May 9th 05, 07:36 PM
Pat Flannery
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Ed Kyle wrote:

Ed Kyle wrote:


So to get the costs for a shuttle-derived system down
to something reasonable - say $400 million per flight
at four launches per year - NASA would have to establish
a program that only employed around 6,500 (total, for
everything from factory to control center to parking
lot security, etc). This is only about one-third of the
total currently involved in the space shuttle program.
(Or it could employ the same number of workers at 1/3rd
the pay.)



Or NASA could do something remarkable and design
CEV to fly atop existing EELV assets. If four
launches were to occur each year, then the EELV
production rate would be increased from 8 to 12
annually and the per-flight launch services cost
would drop from about $120 million to $80 million
(a bit of guessing).

The problem here is that you need a minimum of four EELV launches to
land a man on the Moon if the LockMart design is chosen:
Launch one carries the CEV, launch two carries the TEI stage and living
area/docking module (as shown in the LockMart "Lunar Train" drawing),
launch three carries the lunar descent/ascent module, and launch four
carries the TLI/Lunar orbital braking module.
If these are using cryogenic propellants, you've got to get them all
into LEO in fairly short order to prevent excessive propellant boil-off.
If there is a launch failure of any of the components, or a failure to
assemble them in LEO, then the whole mission is off.
I can see assembling two components in LEO- but _four_ (and that's a
minimum; it could end up being five or six)?!
Compared to Apollo's single Saturn V launch, this sucks.
With the unmanned shuttle cargo variant, you could send up everything
except the CEV in one launch, and then launch it separately with the
crew. Since you would be using two separate pads, this would save the
money on building more pads for the EELV only option's need for four or
more rapid turnaround launches to accomplish this mission.

Pat


  #16  
Old May 9th 05, 07:53 PM
Ed Kyle
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wrote:
Ed Kyle wrote:

Or NASA could do something remarkable and design
CEV to fly atop existing EELV assets.

...
It won't happen.


The astronaut corp apparently desperately hopes not. The hydrogen

fire
on Delta IV scared the bejeesus out of everyone who saw it; DIV

cannot
fulfill the CEV mission without solid-rocket strapons (up to 7, if
memory serves), thus negating the already dubious safety superiority

to
solids; and the DIV has to fly an odd trajectory (due to structural
concerns) that means that there are points in the ascent when abort

is
*not* survivable. Atlas V heavy is a bit of an unknown, but apprently
has a number of the same performance issues.


The Delta IV Heavy hydrogen flare was wild, but the
rocket is designed to catch on fire (!) - and such
events can reportedly be damped out if a water
suppression system is added to the pad. Still, the
sight could not have been good "PR" for Boeing's
rocket. (An aside - I once watched a hydrogen fire
burning on Pad 39A after an abort. The flames
licked right up the side of the orbiter (Discovery
I think it was - with crew on board and ET fueled)
discoloring the exterior. It burned for awhile and
was more than a little uncomfortable to watch).

The Heavy trajectory kept the rocket over land
for a longer time than a thrust-augmented Medium,
but I suspect it took Saturn V as much time to
clear the beach.

Both Delta IV and Atlas V have the same problems
when it comes to CEV adaptation. Neither can handle
a projected 20 ton CEV without core booster
augmentation, (solid or liquid strap-on boosters).
But NASA is either going to have to live with
this or go shuttle-derived. I don't see the U.S.
government (at least not the current one) coming up
with the billions it will take to develop a new,
more powerful core rocket just to launch CEV a few
times a year.

- Ed Kyle

  #17  
Old May 9th 05, 08:12 PM
Pat Flannery
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wrote:

The astronaut corp apparently desperately hopes not. The hydrogen fire
on Delta IV scared the bejeesus out of everyone who saw it; DIV cannot
fulfill the CEV mission without solid-rocket strapons (up to 7, if
memory serves), thus negating the already dubious safety superiority to
solids; and the DIV has to fly an odd trajectory (due to structural
concerns) that means that there are points in the ascent when abort is
*not* survivable. Atlas V heavy is a bit of an unknown, but apprently
has a number of the same performance issues.


Looking at the LockMart CEV design with add-on living/docking area at
the back reminds me of the way Hermes slowly grew into a reusable
spaceplane with the nonreusable section hanging on the back, ruining the
economics of the system- but at least in that case they had it going up
on one Ariane booster; in this case it takes two launches to get to the
same sort of configuration.
Question of the week- where are the radiators located on CEV in its
stand-alone orbital configuration? On the bottom of the extensible solar
arrays? Or are the "solar arrays" shown in the drawings really
radiators, and the electrical power derived from onboard fuel cells? You
can see the radiator hanging off of the back module, but no obvious one
on the CEV; and it will need one given it TPS covering.
The lifting body design gives the vehicle great cross range, which is
said to be in the interests of safety, and to avoid water landings.
Given the present administration's desire for military space control,
one can wonder if the great cross range requirement had a similar origin
to that of the Shuttle's, with its delta wings- something the military
wants for a military derivative of the CEV.
Hopefully, we aren't walking down the "one-size-fits-all" path of
spacecraft design again.

Pat
  #18  
Old May 9th 05, 08:49 PM
Pat Flannery
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Rand Simberg wrote:

Or subcool the propellants and insulate the tanks properly...


Still, how long would one have to get it all stuck together? Days or weeks?
The Soviet's did a stage (Block D) that used an insulation sunshade for
it LOX/Kerosene propellant on Proton-Zond and N-1:
http://www.myspacemuseum.com/l1s_2.jpg
But do we have any experience with this sort of thing? The closest we
came was the canceled Shuttle boosted Centaur stage.

Pat
  #19  
Old May 9th 05, 08:54 PM
Reed Snellenberger
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Pat Flannery wrote:

Is there any breakdown regarding how many of those are related to
orbiter inspection, TPS repair, and SSME (I assume that the cargo
version wouldn't use SSMEs, but rather expendable RS-68s for the sake of
economy and system simplicity) postflight checkout and maintenance?


Assuming that the shuttle goes away in 2010, there shouldn't be any
objection to using the remaining inventory of SSMEs as expendables for a
heavy lift vehicle.

Leaving aside the six that have been lost in flight, there seem to be
about 40 engines in the inventory (2005 through 2109), most of which
have fewer than 10 flights. Even omitting the workhorse engines (i.e.,
2012 with 22 flights), sufficient engines remain for several flights of
a shuttle-derived heavy lifter. (I get my numbers from the available
vehicle descriptions in press kits -- STS-108 omitted that info for some
reason).

Of course, the engines would be a mix of base, Block I, Block II, etc --
but if overall performance is an issue, either mix similar engines in
the same cluster or design the flights around the nominal thrust levels
for the least-capable engine (i.e., use 100% if the flight includes a
base engine, 104% if the worst engine is a Block I).

They're bought & paid for, and their only other use is as expensive
paperweights in a few museums. It would actually be *more* expensive to
replace them with RS-68s, since they'd have to be purchased (assuming
that the SSMEs have been stored in reasonably controlled conditions).

--
Reed Snellenberger
GPG KeyID: 5A978843
rsnellenberger-at-houston.rr.com
  #20  
Old May 9th 05, 09:00 PM
Pat Flannery
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Rand Simberg wrote:

So we don't care if we lose a billion-dollar payload? Or the price of
relaunching?

This notion of reliability being of no relevance for unmanned systems
gets tiresome.



Not to the same degree... for a manned launch you want around 99+%
reliability if at all possible; for unmanned you can settle for 95%-97%
(like most operational expendable rockets have) and realize that the
loss of a couple in 100 launches will be more than offset by the money
you save in not having to design and build to quite the high standards
required to get to 99+%. It's where those last few percentage points
start coming into play that you run into lots of added dollars- and
extra equipment weight to overbuild things to make critical things
redundant. Which cuts into your payload weight, and therefore ups your
launch price per pound for large numbers of launches.

Pat

 




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