Author Topic: SLS General Discussion Thread 2  (Read 225026 times)

Offline MarcAlain

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Re: SLS General Discussion Thread 2
« Reply #80 on: 09/21/2015 04:35 AM »
Well, not dozens. They'd likely have to double or triple their manufacturing capacities. Michoud can turn out a max of 4 per year, right?

NASA has currently set up the production rate to support building slightly less than two per year, and with some additional funding they can get up to two per year.

I'd be really happy if we got two launches per year.

Offline Oli

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Re: SLS General Discussion Thread 2
« Reply #81 on: 09/21/2015 08:08 AM »
Is a hydrogen second stage even necessarily a bad thing when you're using solids as your main thrust/first stage?

What would the performance benefits be if they used similar thrust RP1 engines on the main liquid/second stage?

RP-1 is the best choice there is for a first stage due to its ISP-DENSITY.

RP-1 would have been far better for either an SLS first stage or for its boosters, and Hydrogen is the best choice for an upper stage.

- The impulse density of solid rockets is almost twice that of rp-1. Its also fairly easy to create lots of thrust with them.

- You could argue the SLS first stage a ground-lit upper stage.

We can determine fairly closely the marginal cost of a Delta-IV Heavy DOD launch from the 2014 block-buy since this block buy was pure marginal cost.  The Engineering, launch operations, and Infrastructure had already been paid for.  You had 36 cores purchased for $4.3 Billion, which equals about $120 Million a core so we can infer about $360 Million for the incremental cost of a Delta-IV Heavy.

To my knowledge the AF buys launches, not cores.


Apples to oranges.  Unless you're trying to tell me that the Delta IV Heavy price is pure marginal cost,

No, one for one.  An additional Delta IV Heavy price would be almost pure marginal cost.   Anyways, if it isn't, it still makes the case that it is way cheaper than SLS.

Well we don't know the price of an "additional" D4H, do we?
« Last Edit: 09/21/2015 08:09 AM by Oli »

Online Chris Bergin

Re: SLS General Discussion Thread 2
« Reply #82 on: 09/21/2015 02:24 PM »
Stay on topic guys. It gets really boring really fast when people start comparing SLS to Delta IV.

Online Brovane

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Re: SLS General Discussion Thread 2
« Reply #83 on: 09/21/2015 05:59 PM »
Stay on topic guys. It gets really boring really fast when people start comparing SLS to Delta IV.

The Delta-IV is the closest rocket we have to the SLS to compare cost. 
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Online Brovane

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Re: SLS General Discussion Thread 2
« Reply #84 on: 09/21/2015 06:03 PM »

We can determine fairly closely the marginal cost of a Delta-IV Heavy DOD launch from the 2014 block-buy since this block buy was pure marginal cost.  The Engineering, launch operations, and Infrastructure had already been paid for.  You had 36 cores purchased for $4.3 Billion, which equals about $120 Million a core so we can infer about $360 Million for the incremental cost of a Delta-IV Heavy.

To my knowledge the AF buys launches, not cores.


That wording of "cores" is directly lifted from the Air Force press desk. 
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Offline sdsds

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Re: SLS General Discussion Thread 2
« Reply #85 on: 09/21/2015 07:28 PM »
NASA has currently set up the production rate to support building slightly less than two per year, and with some additional funding they can get up to two per year.

I think that's the interesting "marginal cost" to look at. Assume the anticipated rate is "three every two years." What is the incremental cost to reach "four every two years?" I think this is similar to what oldAtlas_Eguy attempts to estimate, with the result of $600M.

At the full production rate capability of 2 every year the per launch cost would be from $.9B to $1B or $3.6B to $4B every 2 years <$2B more for three more flights in the same period or additional budget required of $600M per flight!!!!

I personally believe it might be less than that, and by establishing a more natural cadence of operations might decrease the total likelihood of a LOM/LOC event. And the "cost" of just one of those would be enormous!
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Online Coastal Ron

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Re: SLS General Discussion Thread 2
« Reply #86 on: 09/21/2015 08:59 PM »
NASA has currently set up the production rate to support building slightly less than two per year, and with some additional funding they can get up to two per year.

I think that's the interesting "marginal cost" to look at. Assume the anticipated rate is "three every two years." What is the incremental cost to reach "four every two years?" I think this is similar to what oldAtlas_Eguy attempts to estimate, with the result of $600M.

What is missing in all these "marginal cost" estimates is the biggest factor - real cost data.  Without that it's impossible to understand what the effects are of increasing or decreasing production rates.  That's why comparisons of other launch systems, such as the Shuttle and Delta IV Heavy, are really the closest we can get today.
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Offline 93143

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Re: SLS General Discussion Thread 2
« Reply #87 on: 09/22/2015 01:49 AM »
what the effects are of increasing or decreasing production rates.

This.

You guys aren't getting this.  You can't calculate marginal cost from expenditure breakouts.

It isn't just the primary contractor that has fixed costs and variable costs.  Every subcontractor and part supplier does too.  And if you're a substantial fraction of someone else's business, your purchase rate will strongly affect their economies of scale, changing the price of the item(s).

So the only real way to get marginal cost is to figure out how the cost/price of everything you need changes with flight rate and compare the total program costs between different scenarios.  If you do this, you will get much lower numbers than anything you could calculate directly from your actual budget.

Please note that with the EELV program, it isn't that non-DoD customers are charged incremental cost, however that's calculated.  They're charged normally, and the DoD is reimbursed for the fixed cost thus defrayed.  And apparently the amount of the reimbursement has been controversial in the past; the DoD was still complaining even after it tripled...

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Can anyone defend talk of a single "marginal cost" value given the actual anticipated flight rate?

Sorta, yeah.  See the previously-linked chart from DIRECT for J-246.  Goes all the way from one flight per year to 16.  They did a bunch of these, plotting program cost or launch cost or cost per kilogram vs. flight rate for a variety of LVs.  Total costs tend to be largely fixed costs until the flight rate gets high enough, at which point variable costs (basically the stack of marginal costs on top of the fixed cost) start to dominate.  If extra infrastructure is required to go past a certain flight rate, there's a bump in the curve after that point due to the extra overhead (there'd be capital costs too, but those aren't recurring costs).

But marginal cost itself is not strongly dependent on flight rate, as long as you're within the infrastructure's capacity.  There's a bit of a learning curve, but the linked estimate shows a marginal cost of ~$320M in 2015 dollars to go from one flight per year to two, and ~$250M in 2015 dollars to go from seven flights per year to eight.

This particular contract was able to leverage being a continuation of previous contracts, so the workforce was already in place and stable, the supply chain was mature, and costs were well known.

The SLS SRM's, which are 5-segment, and new designs, can only be more expensive, not less than, what the Shuttle program was paying.

So now you're trying to lump DDT&E into the marginal cost?

The SLS boosters have been reworked for affordability.  If I recall correctly they slashed the required man-hours per segment by nearly 40%.  I'm not sure if they had to spend back some of that to solve the void issue, but it is not true that the boosters can only be more expensive in terms of either fixed or marginal cost, particularly if the manifest stabilizes and the supplier can plan ahead properly.

I would expect total prices to be higher per segment, since the flight rate is so low, but that's not marginal cost.

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The efficiency of a high production rate is simply that you get a lot of work out of your existing facilities and personnel.  Lowering the rate doesn't increase the marginal cost of a unit very much; what it does is increase that unit's share of the fixed costs.
Lowering the production rate can affect costs very much, and what we don't know is where the cost inflection point is for SLS production.  It may not be until it reaches something like 4-6 per year (~ Shuttle rate).  NASA is quite proud of how efficient the tooling is for the SLS, which is good for touch labor costs, but overhead and other sustaining costs are going to be significant at low production rates, both for Boeing and every other major contractor for SLS.

That is exactly what I just said, except that you're trying to conflate marginal and total recurring costs to make me look wrong.

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But SLS is being set up for two units per year at steady state; you can only take such a scenario so far before it becomes more expensive than just using the Shuttle infrastructure as it stood, and $1B marginal cost per launch is past that point.  I don't see this as a serious possibility, not at the scale you people are talking about.
The Shuttle shouldn't enter into this, since it was not a comparable transportation system, despite sharing some design elements.

You didn't read my links, did you?

The ESD Integration document contains multiple program cost estimates for an early version of SLS, based heavily on STS numbers where possible and CxP numbers where necessary.  Cases #3 and #4 finish development and set up a steady launch cadence, and Cases #4a and #4b are identical except that #4a contains an extra Block 1 launch per year (with Delta Heavy "kick stage"), which enables a direct comparison of annual budgets.  When I deflate the results using the inflation rates apparent in the data, the result is around $330M per year in modern dollars.  I think the Block 1 in question uses three main engines, so $350M is probably a better estimate for Block 1 as we know it.  Bump it up a bit for Block 1B, but don't just add parts costs because that will give you an overestimate - RL-10s are very cheap in terms of marginal cost, but AJR has to keep the doors open somehow.

The DIRECT chart I linked contains a plot of program cost vs. flight rate for a directly Shuttle-derived launch vehicle broadly comparable to SLS (J-246 = 2 cryo stages, 4xRS-25, 6xRL-10, 4-seg, unstretched core).  Just so you know (I don't imagine you're going to go look), it shows a baseline cost of just over $2B (maybe $2.06B, measuring on the image) for one launch per year, $2,348M at two per year, $2,866M at four per year, and so on up to $5,479M at 16 per year (this was before SpaceX took over 39A).  Those are 2009 dollars; multiplying by 1.123 to get 2015 dollars (NASA New Start 2014), it seems the estimate is about $320M to go from one flight per year to two.  SLS is a little bigger (more of a J-244SH (Stretched Heavy) than a J-246), so the numbers would probably be a little higher, all else being equal (all else is not equal because SLS is a modernized design without direct operational continuity).

SLS is a Shuttle-derived vehicle; it's not as directly derived as it might have been, but pretty much all the changes besides the core stretch and the extra booster segment are either directly or indirectly ops cost reductions.  As I said, it is possible that they could be trading higher marginal cost for lower fixed cost, but as I said the marginal cost can only go so high before this becomes counterproductive at the flight rate they're targeting.  Even with very low fixed costs, a marginal cost of $1B per flight (in addition to not passing the smell test) seems like it would be getting to the point where a more directly derived vehicle would have been cheaper to run at the targeted flight rate of two per year, so I don't consider that a reasonable possibility.

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The key though is that no upsized transportation system should be built until the existing transportation has been maxed out, and the new system is going to provide increased capacity for a known customer demand.

NASA is not a commercial launch provider, that has to respond to customer demands.  NASA is a space agency; one of its primary goals is to explore space, and it is currently planning to attempt manned deep space exploration.  To send people up there, NASA needs a hardware-moving capability that doesn't exist in the private sector.  There are a lot of options - depots, juiced-up versions of existing LVs, maybe SEP tugs for cargo shots - but they all cost billions in DDT&E that NASA has to ask the government for, and the option that the government seems to be willing to provide those billions for is SLS.
« Last Edit: 09/22/2015 03:21 AM by 93143 »

Online Coastal Ron

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Re: SLS General Discussion Thread 2
« Reply #88 on: 09/22/2015 03:17 AM »
You guys aren't getting this.  You can't calculate marginal cost from expenditure breakouts.

Being someone that has done cost rollups, actual numbers are better than generalized high level estimates.

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It isn't just the primary contractor that has fixed costs and variable costs.  Every subcontractor and part supplier does too.  And if you're a substantial fraction of someone else's business, your purchase rate will strongly affect their economies of scale, changing the price of the item(s).

I agree with that.  Which is why estimates that don't take into account flight rate, procurement lead time and buy quantities are prone to be inaccurate.  And we don't know any of those at this point.  NASA would have the best numbers, although they have not published them, but even so they don't know what Congress is going to allow them to procure on their first production buy.

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Please note that with the EELV program, it isn't that non-DoD customers are charged incremental cost, however that's calculated.  They're charged normally, and the DoD is reimbursed for the fixed cost thus defrayed.  And apparently the amount of the reimbursement has been controversial in the past; the DoD was still complaining even after it tripled...

The ELC covers the launch infrastructure for USG payloads, and is a subsidy that is going away.  It was never part of the cost for the launch vehicle.

Now remember that ULA's pricing is very opaque according to the GAO, so we really don't know how they price Atlas V and Delta IV/H.  And commercial payloads would have different payload handling needs than Air Force payloads, so that cost would have to be known too.

But you and I have no idea whether ULA charges "incremental cost" or uses some other method.  We don't have insight into that, nor should we since they are a private company.

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Can anyone defend talk of a single "marginal cost" value given the actual anticipated flight rate?

Sorta, yeah.  See the previously-linked chart from DIRECT for J-246.  Goes all the way from one flight per year to 16.

I can appreciate the detailed work the DIRECT folks did, but their assumptions were based on the continued use of the Shuttle supply chain.  The Shuttle supply chain ended, so the SLS can't leverage that, even for the SRM's.  Plus the SLS is a completely different design, which greatly affects projected costs.

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But marginal cost itself is not strongly dependent on flight rate.

Of course it is.  Maybe because I've been directly involved with defining production schedules and procurement buying decisions I understand this better than most.  There is a unique cost associated with every single part, and it is affected by your consumption rate (i.e. flight rate) and how much (and how often) you are buying for each part.  Those are major cost drivers for suppliers, as well as Boeing who is doing fabrication and final assembly.

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This particular contract was able to leverage being a continuation of previous contracts, so the workforce was already in place and stable, the supply chain was mature, and costs were well known.

The SLS SRM's, which are 5-segment, and new designs, can only be more expensive, not less than, what the Shuttle program was paying.

So now you're trying to lump DDT&E into the marginal cost?

My comment was related to the supply chain.  You do realize that suppliers won't keep worker sitting around twiddling their thumbs waiting for an SLS-related order to come in, right?  So they may have to train new workers or retrain prior workers on how to build SLS-related parts that are ordered infrequently.  That is added to the procurement price, since it a cost NASA has to bear, not the supplier.

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The SLS boosters have been reworked for affordability.  If I recall correctly they slashed the required man-hours per segment by nearly 40%.

Yes, finally after 135 flights ATK suddenly gets concerned about cost...

Look, if the SLS only flies once per year, then only 10 segments are needed per year.  And now that they are so much more efficient those same workers will be reassigned to work on something else for most of the year - or not, depending on whether their skills and work location allows that.  Those are pricing factors that are unknown at this point because we don't know what the flight rate is, and how many SLS NASA will be allowed to buy for, and what NASA will want for a delivery schedule.

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The key though is that no upsized transportation system should be built until the existing transportation has been maxed out, and the new system is going to provide increased capacity for a known customer demand.

NASA is not a commercial launch provider, that has to respond to customer demands.

NASA has no institutional skills for being a launch provider of any kind, and with the SLS they will have internal customers that they will have to respond to.  Which is why NASA should not be in the launch business.  The private sector, which was never asked, could have responded to any needs they had.
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Offline 93143

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Re: SLS General Discussion Thread 2
« Reply #89 on: 09/22/2015 04:25 AM »
I can appreciate the detailed work the DIRECT folks did, but their assumptions were based on the continued use of the Shuttle supply chain.  The Shuttle supply chain ended, so the SLS can't leverage that, even for the SRM's.  Plus the SLS is a completely different design, which greatly affects projected costs.

Handwaving.  Am I supposed to assume that "greatly affects projected costs" means "triples the marginal cost of a launch"?

SLS is not a "completely different design".  It's an inline Shuttle-derived launch vehicle that's actually quite similar to Jupiter, but a little bigger, with modernizations and cost reductions.  You can't pretend Delta IV is a closer analogue than Jupiter.

Or didn't you notice that the marginal cost off the J-246 plot from 2009 is almost identical to the marginal cost I backed out of the ESD Integration SLS estimates from 2011?

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There is a unique cost associated with every single part, and it is affected by your consumption rate (i.e. flight rate) and how much (and how often) you are buying for each part.  Those are major cost drivers for suppliers, as well as Boeing who is doing fabrication and final assembly.

I just got through saying exactly that, except that I'm not trying to redefine "marginal cost" to mean "purchase price".  (Admittedly, I have had disagreements over terminology before, but it should be pretty obvious what I mean by this point.)

All that consumption rate dependency is due largely (not entirely, but in the main) to fixed cost; you buy less of something, or buy more sporadically, and the supplier's overhead becomes a bigger portion of the total, so the price per unit goes up.  This is a particularly strong effect if you're the sole customer for an item, since you have to eat the supplier's entire fixed cost regardless of how many you buy.  But it doesn't matter whose fixed cost it is; it's still fixed cost.

If you actually plot the total program cost vs. flight rate for a large launcher program with a reasonably well-defined launch schedule, the slope changes fairly slowly.  That slope is the marginal cost I'm talking about.
« Last Edit: 09/22/2015 05:29 AM by 93143 »

Offline sdsds

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Re: SLS General Discussion Thread 2
« Reply #90 on: 09/22/2015 05:37 AM »
the marginal cost off the J-246 plot from 2009 is almost identical to the marginal cost I backed out of the ESD Integration SLS estimates from 2011

OK, that's impressive for sure.

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If you actually plot the total program cost vs. flight rate for a large launcher program with a reasonably well-defined launch schedule, the slope changes fairly slowly.  That slope is the marginal cost I'm talking about.

FWIW I'm kind of convinced.
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Offline Steven Pietrobon

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Re: SLS General Discussion Thread 2
« Reply #91 on: 09/22/2015 06:20 AM »
For what its worth, I crunched some numbers on SLS Block II costs using the NASA cost estimator. Per vehicle costs (not including development cost) with solid boosters was $680M to $810M and with liquid boosters it was $1.3B to $1.5B.

http://www.sworld.com.au/steven/pub/SLS-Moon-200715.pdf
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Offline spacenut

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Re: SLS General Discussion Thread 2
« Reply #92 on: 09/22/2015 01:44 PM »
What payload increase would the proposed liquid boosters give over solids?  Is the increase worth the cost increase? 

Online Brovane

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Re: SLS General Discussion Thread 2
« Reply #93 on: 09/22/2015 07:37 PM »

All that consumption rate dependency is due largely (not entirely, but in the main) to fixed cost; you buy less of something, or buy more sporadically, and the supplier's overhead becomes a bigger portion of the total, so the price per unit goes up.  This is a particularly strong effect if you're the sole customer for an item, since you have to eat the supplier's entire fixed cost regardless of how many you buy.  But it doesn't matter whose fixed cost it is; it's still fixed cost.

If you actually plot the total program cost vs. flight rate for a large launcher program with a reasonably well-defined launch schedule, the slope changes fairly slowly.  That slope is the marginal cost I'm talking about.

I cannot argue with this point about fixed cost and marginal cost to increase the number of flights.  Based on what you are showing in your graphs, the Jupiter-246 showed a marginal cost of ~320 Million and you expect the SLS to be in the same range?  Since the SLS is also Shuttle derived hardware. 
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Online Coastal Ron

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Re: SLS General Discussion Thread 2
« Reply #94 on: 09/22/2015 08:00 PM »
SLS is not a "completely different design".  It's an inline Shuttle-derived launch vehicle that's actually quite similar to Jupiter, but a little bigger, with modernizations and cost reductions.

In manufacturing it's pretty black and white.  Either something is the same, or it's different.

The SLS is not a stretched Shuttle ET.  Other than the diameter of the SLS 1st stage, the Shuttle ET and the SLS 1st stage are of different designs, which makes sense since they have completely different load paths (i.e. side mount vs top loading).  Even the SRM's are completely different.  Plus the Shuttle didn't have a 2nd stage, so that is all new.

I think you need to read up on what the manufacturing challenges are for the SLS to better appreciate how different the SLS is from the Shuttle.  Here is one article to read:

SLS takes on new buckling standards, drops Super Light alloy | NASASpaceFlight.com

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You can't pretend Delta IV is a closer analogue than Jupiter.

We have real prices for Delta IV/H, we don't have any real prices for Jupiter.  I know you feel paper studies will yield perfect information, the reality is that they don't represent reality, and reality could be higher and it could be lower in cost.

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I just got through saying exactly that, except that I'm not trying to redefine "marginal cost" to mean "purchase price".

The cost of buying material is an important part of determining "marginal cost".  However as I've shown with the Shuttle program, determining "marginal cost" from public sources is not easy because of the various procurement decisions that are made based on lead times, lot quantities, risk, and many other factors that don't get articulated to the public.

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If you actually plot the total program cost vs. flight rate for a large launcher program with a reasonably well-defined launch schedule, the slope changes fairly slowly.  That slope is the marginal cost I'm talking about.

Just because they intercept doesn't mean they are accurate.  We'll have to wait until Congress allows NASA to buy SLS production material before we find out what the real prices are.  But until then, based on using common sense and rough orders of magnitude, the SLS is going to be significantly more expensive than a $400M Delta IV Heavy - there is no way it can be close to the same or less.
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Offline 93143

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Re: SLS General Discussion Thread 2
« Reply #95 on: 09/22/2015 08:22 PM »
Based on what you are showing in your graphs, the Jupiter-246 showed a marginal cost of ~320 Million and you expect the SLS to be in the same range?  Since the SLS is also Shuttle derived hardware.

Basically, yeah.

The leaked ESD Integration document from 2011 seems to back me up.  Cases #4a and #4b have a few years at the end where development is over and the launch rate is steady (and plainly continues well into the future); aside from the "In Space Elements Wedge", the only difference is that #4a has an extra "70-ton" SLS launch every year (this vehicle seems to include a Delta Heavy upper stage).  The cost difference, summing SLS and ground systems, is $414M in 2023, $426M in 2024, and $437M in 2025.

The inflation rate in NASA New Start 2010 (use in FY11) is 2.6% from 2012 to the end of the table, except for 2013 and 2017 in which it is 2.7%.  This matches nicely with the rate of inflation apparent in the ESD Integration data.  Using NASA New Start 2010 (use in FY11) to deflate to 2011 and NASA New Start 2014 (use in FY15) to inflate it back to 2015 results in a marginal cost in modern dollars of about $330M.

$330M is pretty darn close to $320M considering the differences between the two vehicle designs, and the fact that one is measured off a graph and inflated by six years, while the other is deflated by fourteen years and reinflated by four...

Considering how close the deflated fixed costs are to the DIRECT estimate, as well as the fact that the estimates are explicitly said to be based on STS and CxP, I suspect there wasn't much modernization or cost reduction in the numbers.  If this is true, the actual vehicle should end up less expensive overall on an ongoing basis, though not necessarily on a marginal basis.


@Coastal Ron:  I never said the SLS estimates were perfect, or that much (or indeed any) of the design was identical to anything in the old Shuttle stack.  But neither of those things needs to be true for estimates based on the old technology to be useful in getting a rough idea of what the new technology might cost.  Sure, it's possible for a rash of slight design changes to cause the cost of an item to skyrocket, but intelligent engineers don't do that, and intelligent project managers don't let the dumb engineers do it either.

The major tech changes are all cost-reduction measures.  They're not going to cause the marginal cost to triple.

As for the Delta IV comparison...  I don't see why I should have to respond further.
« Last Edit: 09/22/2015 08:37 PM by 93143 »

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Re: SLS General Discussion Thread 2
« Reply #96 on: 09/22/2015 08:24 PM »
We'll have to wait until Congress allows NASA to buy SLS production material before we find out what the real prices are. 

Are you seriously suggesting the cost of aluminum is significant in the incremental cost of one more SLS flight?
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Re: SLS General Discussion Thread 2
« Reply #97 on: 09/22/2015 08:42 PM »
Based on what you are showing in your graphs, the Jupiter-246 showed a marginal cost of ~320 Million and you expect the SLS to be in the same range?  Since the SLS is also Shuttle derived hardware.

Basically, yeah.

The leaked ESD Integration document from 2011 seems to back me up.  Cases #4a and #4b have a few years at the end where development is over and the launch rate is steady (and plainly continues well into the future); aside from the "In Space Elements Wedge", the only difference is that #4a has an extra "70-ton" SLS launch every year.  The cost difference, summing SLS and ground systems, is $414M in 2023, $426M in 2024, and $437M in 2025.

The inflation rate in NASA New Start 2010 (use in FY11) is 2.6% from 2012 to the end of the table, except for 2013 and 2017 in which it is 2.7%.  This matches nicely with the rate of inflation apparent in the ESD Integration data.  Using NASA New Start 2010 (use in FY11) to deflate to 2011 and NASA New Start 2014 (use in FY15) to inflate it back to 2015 results in a difference of about $330M.

$330M is pretty darn close to $320M considering the differences between the two vehicle designs, and the fact that one is measured off a graph and inflated by six years, while the other is deflated by fourteen years and reinflated by four...

Considering how close the deflated fixed costs are to the DIRECT estimate, as well as the fact that the estimates are explicitly said to be based on STS and CxP, I suspect there wasn't much modernization or cost reduction in the numbers.  If this is true, the actual vehicle should end up less expensive overall on an ongoing basis, though not necessarily on a marginal basis.

I cannot argue with that reasoning.  The difference that I keep forgetting between the SLS and Delta-IV is that the majority of the hardware development cost was paid for by Boeing and they charge a margin to make back that development cost above the normal hardware cost.  Which is perfectly reasonable.  The major components of the SLS are being developed and paid for using government funds.  Even the factory from the main booster tank is government facility, the transport vehicles are government vehicles.  We will see what the actual costs are once the flight program starts.  However you have made a sound argument for a marginal cost of around ~$320 Million,  I stand corrected.     
"Look at that! If anybody ever said, "you'll be sitting in a spacecraft naked with a 134-pound backpack on your knees charging it", I'd have said "Aw, get serious". - John Young - Apollo-16

Offline 93143

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Re: SLS General Discussion Thread 2
« Reply #98 on: 09/22/2015 08:50 PM »
Well, with design differences and tech changes and the optimization of production for a low flight rate, there's probably a good deal of wiggle room in that number.

Personally, I think a full-up Block 1B should have a marginal cost to go from one flight per year to two of somewhere between $300M and $400M.  Higher and lower are both possible.  But I would be very surprised if it got up near $1B; that seems downright unreasonable...
« Last Edit: 09/22/2015 08:52 PM by 93143 »

Online Brovane

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Re: SLS General Discussion Thread 2
« Reply #99 on: 09/22/2015 08:54 PM »
Well, with design differences and tech changes and the optimization of production for a low flight rate, there's probably a good deal of wiggle room in that number.

Personally, I think a full-up Block 1B should have a marginal cost to go from one flight per year to two of somewhere between $300M and $400M.  Higher and lower are both possible.  But I would be very surprised if it got up near $1B; that seems downright unreasonable...

Well what will happen is if the fixed costs are $2 Billion for 1-flight and 2-flights are $2.4 Billion then it will be reported that each launch costs $1.2 Billion.  Just like the B-2 Bomber is quoted as costing $2 Billion per plane when at the end of the Production run, the incremental cost of adding another air-frame to the production run was ~$500 Million.  A couple of months ago during one of the Assured Access to Space hearings, the subject of using SLS for DOD launches was brought up by one of the Committee members but the USAF shot it down fairly quickly.  However ULA has stated that after they retire the Delta-IV medium, keeping the production line open for just the Delta-IV Heavy would result in a "significant" increase in price.  Which based on the models you present, a SLS Block-1B would be very price competitive against a Delta-IV heavy.       

To bad NASA cannot due a multi-year procurement block-buy of the SLS-Block 1B.  I would suspect that this would save even more money per LV.  However that would also mean that actual missions are also funded for the SLS.  Instead Congress likes to keep a tight rein on the purse strings, year to year.   
« Last Edit: 09/22/2015 09:01 PM by Brovane »
"Look at that! If anybody ever said, "you'll be sitting in a spacecraft naked with a 134-pound backpack on your knees charging it", I'd have said "Aw, get serious". - John Young - Apollo-16

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