Author Topic: SLS General Discussion Thread 2  (Read 223715 times)

Offline Coastal Ron

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Re: SLS General Discussion Thread 2
« Reply #60 on: 09/15/2015 05:13 PM »
Its pretty easy. The marginal cost is what was needed to be added to the budgets beyond the yearly sustaining costs. The Shuttle didn't fly the same number of times every year. Thus they had to budget for each mission they flew.

No, that is not how the Shuttle program was funded, which goes to show why trying to estimate marginal costs is so fraught with potential for being underestimated.

For instance, the Shuttle External Tank (ET) and Solid Rocket Motors (SRM) were purchased in large multi-year contracts.  Sometimes those contracts were further amended, extending the contract periods too.  Here are two articles that show that:

NASA Extends Space Shuttle External Tank Contract - SpaceRef
NASA Extends Reusable Solid Rocket Motor Contracts with ATK Thiokol Through May 2007 - SpaceRef

Even the contract with USA was multi-year, which replaced a quite a few individual contracts that would have had overlapping periods of performance, as well as tasks:

United Space Alliance and NASA Sign Space Flight Operations Contract - Free Online Library

Notice that all of these contracts extended beyond the budget horizon for NASA.  This is something I'm very familiar with, since if I was the scheduling manager for the Shuttle or SLS programs I would be involved with procurement and contracts in defining how far out into the future we would be making purchases for every type of component, from screws to SRM's.

Everything is dependent on volume - how many of something you plan to make.  And it's even more complicated than that, since you have to account for how many, when, and of what configuration.

The more uncertainty there is in quantity, time and configuration means less certainty in cost, since contracts can't be defined and finalized until there is some agreed upon level of certainty.  But when enough can be decided, then contracts are negotiated years in advance of an SLS flight, and years in advance of the approved NASA budget.  You can see that in all three of the articles I referenced above.

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To bring this to SLS the question is if we fly one rocket this year how much more money will it take to fly another. That was the original question.

What I've shown is that it's not easy to determine what the marginal costs are.  And until NASA gets approval to start building operational SLS, and those contracts get negotiated and made public, no one in the public will know what the real marginal costs will be.
If we don't continuously lower the cost to access space, how are we ever going to afford to expand humanity out into space?

Offline notsorandom

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Re: SLS General Discussion Thread 2
« Reply #61 on: 09/15/2015 07:10 PM »
Even with multi-year contracts NASA still has to request a budget one year at a time. The number of manifested flights drove the yearly funding request of STS line item. It boils down to this, either NASA can answer the question of how much more money needs to be in the yearly budget request to launch a rocket or it cannot. It has been launching a rockets and requesting budgets for a while now. NASA is perfectly capable of figuring out the difference in cost between flying one SLS or two.

Offline arachnitect

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Re: SLS General Discussion Thread 2
« Reply #62 on: 09/15/2015 07:21 PM »
Solar Probe Plus is $389 million.

And even with a Delta 4-Heavy launch the mission will need seven flybys of Venus!?! Has anyone explored what SLS with an EUS could do to improve that? It's just a hypothetical... but an interesting one nonetheless.

It has come up in SLS threads.

Boeing has a Solar Probe Plus successor in some of the marketing literature that gets even closer than SP+. I forget exactly which version of SLS it uses.

Offline Coastal Ron

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Re: SLS General Discussion Thread 2
« Reply #63 on: 09/15/2015 07:56 PM »
Even with multi-year contracts NASA still has to request a budget one year at a time.

NASA provides a budget request for more than one year.  The current FY 2016 President's Budget Request Summary covers FY2016 thru 2020, so that is a five year plan.

However Congress may only approve a budget one year at a time.

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The number of manifested flights drove the yearly funding request of STS line item.

You may not have read the articles I linked, or understood the implications of them.  For instance, the External tank was being purchased in block buys that stretched over a 7-year period, meaning it was well beyond the budget planning horizon.

And the reason for that is cost, since buying ET's one at a time would have raised the price quite a bit, whereas doing a block buy results in big cost savings.  We don't know yet what NASA will be allowed to do once Congress authorizes NASA to start building production SLS.

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It boils down to this, either NASA can answer the question of how much more money needs to be in the yearly budget request to launch a rocket or it cannot. It has been launching a rockets and requesting budgets for a while now. NASA is perfectly capable of figuring out the difference in cost between flying one SLS or two.

NASA may know some point in the future, but that doesn't mean the public will know.  And so far NASA has not released any cost information about the SLS, and is very late in doing so.

So in regards to "marginal cost", when the initial development units have not been produced and tested, and NASA has no idea what the initial number of SLS will be that Congress will authorize for procurement, there is not enough valid information to use "marginal cost" to estimate how much a production SLS will cost.

Fascinating subject, for sure, but I'll leave it at that...
If we don't continuously lower the cost to access space, how are we ever going to afford to expand humanity out into space?

Offline 93143

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Re: SLS General Discussion Thread 2
« Reply #64 on: 09/20/2015 06:23 AM »
You seriously think the incremental cost of the SLS is only a few hundred million dollars?

Yes.  What amazes me is that so many people seem to assume it's much higher, despite the fact that this makes no sense at all in light of the cost structure of any other rocket.  The torrent of anti-SLS propaganda, grassroots or otherwise, has done its work well.

I agree with you wholeheartedly that most SLS cost estimates are ridiculously overestimated (I think $500 Million is a little too low though). I was trying to give Rocketman a range of realistically imaginable costs.

Actually, the total cost estimates are probably in the ballpark, as long as you correct for the fact that Orion is usually lumped in.  It's just that people tend to assume that a rocket that costs (for example) $4B to launch once every two years would cost $8B to launch twice in a year, and it is this assumption that needs heading off at the pass.

There's also the effect of the modernization and cost reduction measures, which is not yet known.

Moving from one launch per year to two launches per year will almost certainly increase the annual SLS program budget by less than $500M in modern dollars, probably less than $400M, possibly less than $300M.

And in the absence of real cost numbers (which NASA is very behind on providing) comparisons to existing systems are one way to help estimate costs.
why make assumptions when facts exist?

Right, so how about that ESD Integration document I linked you?

Or this?

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So assuming that the SLS will be the same cost as the Delta IV Heavy, or even possibly less, doesn't look right.

Apples to oranges comparison.  We're talking about the marginal cost of SLS exclusive of fixed program costs, not the total recurring cost.  And it should indeed be similar to or lower than the market price of a DIVH (let's not forget that Delta IV is pretty much the most expensive large launcher for its size in the world, significantly less cost-effective than Atlas V).

Like I said, this is only relevant if you're able to get an SLS at marginal cost but would have to pay the sticker price on a DIVH.  I have suggested the former arrangement for science missions; the latter arrangement is the reason they usually go with Atlas...

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And considering that the current human rated vehicle NASA is building (i.e. Orion MPCV) is costing $8B or more, and taking 18 years until it becomes operational, I'd guess your estimates are probably a little low.

Orion is only doing this badly because the design had to mature under the continually tightening constraints imposed by Ares I.  Oh yeah, and it got outright cancelled at one point, resulting in a staffing gap; I'm sure that left its mark...  The European service module isn't helping the schedule...

Are you familiar with the Xeus concept?  I doubt NASA's $10B estimate for Altair applies to it...

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Now if NASA uses existing ISS modules, then great, not much development needed.  But no real need for the SLS either, since lower cost commercial launchers can deliver them too.

Deliver them where?  This isn't about a bunch of free-floating space station modules in LEO; it's about exploring deep space.

I look at the total cost, while also breaking out the development and operational portions.  It's the only way to get a full up apples-to-apples cost, since "marginal cost" estimates are usually simplified too far

On the contrary.  It's you who's simplifying too far:

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and ignore large classes of costs like overhead.

The whole point of marginal cost is that fixed costs are excluded so you can tell what the effect of a change will be.  Your method doesn't allow that, and someone who doesn't understand the difference between fixed and variable cost will get the impression that adding a flight is obscenely expensive.

Figuring out marginal cost though is not easy.  I've done a lot of digging to figure out marginal costs for the Shuttle program, and though I'm pretty good at it (I've done this for work purposes too), I was never able to use public records to figure it out.

That's funny; I had no trouble...

The marginal cost of a launch in the context of the '90s-era STS program was about $80M in modern dollars.

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Marginal cost doesn't mean a lot if you don't remember how much it took to get to unit #1.

Of course not, but who could forget that?  Except that the SLS bashers insist on including Orion's costs and then neglecting to point out that they've done so; hence the $30B figure to 2021 (it also includes all the KSC work, somewhat more justifiably).

Also, a clarification may be in order.  When I say marginal cost, I don't mean the cost to add a unit to a finite production run.  I mean the cost to add a launch in an ongoing program without a clearly-defined end date, assuming there's enough infrastructure headroom to allow it.  (Since launches are usually scheduled far in advance, I model this as a marginal increase in flight rate.)  Cancelling the program early would allow NASA to save fixed costs as well as marginal costs, since they wouldn't have to keep the program running as long, but I'm not considering that scenario.

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Like all hardware programs, there were pieces and parts laying around that were mismatched purchases, so sure, the last flight could have been added without writing a check for $1.5B.  But that's because the Shuttle program had over-bought, and there were pre-negoitated contracts that could be extended.  And using end-of-life costing for a program just starting out doesn't make sense.

Late in the STS program's life (but before the end-of-life drawdown started), it could do five launches per year for a little over $3B.  That's total recurring cost (not including SFS, but that wasn't specifically part of STS, which is why it's still around).  $650M per launch, give or take (or about $750M in modern dollars), and the marginal cost associated with adding or deleting flights without changing the program duration was far less than that.

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there is no possible way to accurately figure out "marginal cost"

It doesn't have to be figured out to the cent.  But it can be estimated a lot more accurately than you're trying to imply, at least when the duration of the fixed-cost expenditure is not part of the estimate.  It will not cost a billion dollars to add an SLS flight.
« Last Edit: 09/20/2015 08:17 AM by 93143 »

Offline Jim

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Re: SLS General Discussion Thread 2
« Reply #65 on: 09/20/2015 12:27 PM »
There is no way SLS marginal costs are less than a Delta IV Heavy.  SLS has more engines, more structure, more people involved, More contracts, etc.  It will be closer to 1 billion than 500 million.
« Last Edit: 09/20/2015 12:28 PM by Jim »

Offline the_other_Doug

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Re: SLS General Discussion Thread 2
« Reply #66 on: 09/20/2015 03:02 PM »
Getting closer and closer to starting a "Why I Hate SLS" thread and telling everyone to put their unending negative comments about SLS there, so I can ignore it and actually get discussion and updates about the actual vehicle that is being built, and will fly, in the appropriately useful threads.

And I'm not kidding.
-Doug  (With my shield, not yet upon it)

Offline ncb1397

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Re: SLS General Discussion Thread 2
« Reply #67 on: 09/20/2015 03:02 PM »
Here is my cost estimate

4 X SSME: 40 million each, 160 million.
2 X SS-SRB: 25 milion each, 50 million.
1 X RL10-B2: 20 milllion????

The total for propulsion systems is only 230 million. If propulsion is something like half or even most of the cost of a rocket like ULA seems to be claiming, then you can get an estimate for the hardware cost of about 500 million which seems to be in line with what NASA officials are claiming. Of course, accounting for inflation, this number will be higher in the 2020s. So, yeah, adding an SLS is probably a few hundred million more than contracting with ULA for a Delta Heavy(~400 million).

Offline oldAtlas_Eguy

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Re: SLS General Discussion Thread 2
« Reply #68 on: 09/20/2015 04:37 PM »
Um.

The problem is this:
- If the production lines run at a efficient rate (3 LVs in 1.5 years) then the $500M value is probably close to reality.
- But if the production rate is 1 every 2 years then the unit costs can no longer take advantage of running the production lines efficiently at the lowest cost per unit rate causing the cost per unit to about double to nearly $1B per unit.
-  The key would for NASA to purchase SLS's in blocks of 3 to be launched in a period of 5 years. This allows the production to run at the cheaper per unit cost then the production line closes and stays dormant for the next 3.5 years until the next order. Savings would be as high as $2.5B!!!!!
- The next item is the standing army for facility and key personnel to maintain the capability to launch at such a slow rate and to  be able to reopen the production lines. This is the $800-900M per year fixed cost. This makes the per flight costs of 1 every 2 years to be $2.1B to as high as $2.8B.
- 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!!!!

SLS can be run economically but only if congress allows it to do so. But at $1B for 100mt that is a high $10,000/kg vs the FH of about 1/4 that at $2,500/kg. Only justifiable if the payload will not fit or get to where it needs to go using an FH. For bulk or smaller multiple payloads it will be cheaper (much cheaper) to launch them on an FH, even if you launch them singly instead of 3 or 4 at a time.

Offline MarcAlain

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Re: SLS General Discussion Thread 2
« Reply #69 on: 09/20/2015 05:53 PM »
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?

Offline 93143

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Re: SLS General Discussion Thread 2
« Reply #70 on: 09/20/2015 07:36 PM »
You can't assess marginal costs by adding up component prices, because those prices change with flight rate due to economies of scale.  You have to assess total program cost for multiple scenarios and compare them.  Both ESD Integration and DIRECT have done this, and I have reported their results.

(Also, IIRC SRBs were $25M per segment pair, not per booster.  Again, that's purchase price, not marginal cost.)

You also can't just "turn off" the production line, because then you have to re-hire all your workers and retrain their rusty skills (and/or hire a lot of new people and train them from scratch, since most people don't just sit around waiting for the call for 3+ years) before you can do anything.  This also seems like a good way to never work the bugs out of your production line; the launch rate is supposed to be no less than 1 per year for a reason.

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.

There is no way SLS marginal costs are less than a Delta IV Heavy.  SLS has more engines, more structure, more people involved, More contracts, etc.  It will be closer to 1 billion than 500 million.

Apples to oranges.  Unless you're trying to tell me that the Delta IV Heavy price is pure marginal cost, with all fixed costs including supplier fixed costs shoved off onto the DoD...

I suppose it's possible in principle that the marginal cost could be strongly affected by optimizing production for very low flight rates, if the changes were radical enough.  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.
« Last Edit: 09/20/2015 09:02 PM by 93143 »

Offline TomH

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Re: SLS General Discussion Thread 2
« Reply #71 on: 09/20/2015 08:47 PM »
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. You need immense amounts of thrust to fight gravity losses. With RP-1, you don't have the greatest amount of energy per Kg, but you do get the greatest amount of energy per liter (volume).

On an upper stage, ISP is king. Of all chemical engines, Hydrogen has the greatest amount of energy per Kg. At the same time, H2 takes requires a huge amount of volume to contain the fuel.

This is why Hydrogen is not a great choice in general for a first stage. In spite of the high ISP, you need ungodly volume, and the tanks to contain that volume are heavy. RP-1 is dense and the tanks can be smaller, therefore you can have a lot more fuel in the tanks. RP-1 provides the immense amount of thrust to overcome both gravity losses as well as the immense mass inertia of the full sized launch vehicle. Once you are in space, Hydrogen becomes the ideal choice (for chemical propulsion) because you have so much more energy per Kg. There are low thrust/high energy alternatives (once you are beyond LEO), that are better than Hydrogen, but they are not chemical rockets. Ion thrust using SEP (solar electric propulsion) or NEP (nuclear electric propulsion) have much higher ISP. These engines only put out a small amount of thrust per second, but over time, the total thrust they put out is far more than an equal mass of chemical propulsion. You can't use such engines at lower than orbital velocity, because they can't come even close to offsetting the opposing accelerative force of gravity. Once you are in deep space however, they are the best choice.

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. SpaceX uses RP-1 on both stages, but takes performance loss in exchange for cheaper operating costs. This thread, however, is not the appropriate place to discuss any of these issues. They, in fact, have already been discussed in extreme length (think hundreds of threads and tens of thousands of posts) in other NSF forums. If you want to ask more questions, it behooves you to find those other threads, read up so that you have the necessary background knowledge, then pose any questions there. If we continue this mis-vectored tangent here, the moderators WILL delete the posts as being off-topic.

PostScript: Search for RAC-1, RAC-2, RAC-3 design.
« Last Edit: 09/20/2015 08:52 PM by TomH »

Offline Coastal Ron

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Re: SLS General Discussion Thread 2
« Reply #72 on: 09/20/2015 09:57 PM »
You also can't just "turn off" the production line, because then you have to re-hire all your workers and retrain their rusty skills (and/or hire a lot of new people and train them from scratch, since most people don't just sit around waiting for the call for 3+ years) before you can do anything.

This is the conundrum for the SLS, and really any transportation system that doesn't have an existing customer base.

Regarding the production line, it can run as slow as needed without firing and re-hiring the workers.  But that is pretty wasteful, and the only way to get around it is to have a workforce that can trained on multiple production processes so that they can build the SLS components serially.  Not cheap though.

The other part of it though is the items that are purchased, since those factories have the same production challenges.  The SRM's for sure, and likely other significant items.  Those factories have to figure out how to build at less than full production rates, and that affects costs quite a bit.

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This also seems like a good way to never work the bugs out of your production line; the launch rate is supposed to be no less than 1 per year for a reason.

I know Gerstenmaier was quoted about launch cadence, and I think his quote was about the launch personnel, but to some degree it does apply to the whole production chain.

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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.

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There is no way SLS marginal costs are less than a Delta IV Heavy.  SLS has more engines, more structure, more people involved, More contracts, etc.  It will be closer to 1 billion than 500 million.

Apples to oranges.  Unless you're trying to tell me that the Delta IV Heavy price is pure marginal cost, with all fixed costs including supplier fixed costs shoved off onto the DoD...

What ULA has going for them is that they can shift personnel between different production lines, so lower Delta IV production rates don't affect marginal cost as much.  Plus they now have the Bulk Buy contract, so their procurement folks can get price breaks for buying large quantities, even though they are delivered at the same rate they've already been buying them.

It will be interesting to see what Congress allows NASA to buy in their first production lot - only buy what has missions approved, or buy based on the forecast of flying X/year, regardless if there is a payload funded yet.

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I suppose it's possible in principle that the marginal cost could be strongly affected by optimizing production for very low flight rates, if the changes were radical enough.

Because the SLS is unique, and because it's being built for NASA in NASA facilities as opposed to a Boeing factory that it could share overhead and workforce with, SLS costs are going to be very high at low rates.  Not much that can be done about that.

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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.

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.  That is not the SLS, and because of that it is a big gamble.  Time will tell...
If we don't continuously lower the cost to access space, how are we ever going to afford to expand humanity out into space?

Offline Jim

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Re: SLS General Discussion Thread 2
« Reply #73 on: 09/20/2015 10:01 PM »
(Also, IIRC SRBs were $25M per segment pair, not per booster.  Again, that's purchase price, not marginal cost.)

That was the cost of the SRM's and not the SRB's.
« Last Edit: 09/20/2015 10:01 PM by Jim »

Offline Jim

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Re: SLS General Discussion Thread 2
« Reply #74 on: 09/20/2015 10:05 PM »

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.

Offline Coastal Ron

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Re: SLS General Discussion Thread 2
« Reply #75 on: 09/21/2015 01:01 AM »
(Also, IIRC SRBs were $25M per segment pair, not per booster.  Again, that's purchase price, not marginal cost.)

That was the cost of the SRM's and not the SRB's.

As a point of reference, on a contract that ended in 2007 for 70 Shuttle SRM's their average cost was $34.3M each, or $68.6M per set.  Here is an article that talks about that contract.

Two things to keep in mind about those cost though:

1.  The contract was a multi-year contract for 70 total SRM's, so they were able to leverage volume discounts and known work levels.

2.  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.
If we don't continuously lower the cost to access space, how are we ever going to afford to expand humanity out into space?

Offline sdsds

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Re: SLS General Discussion Thread 2
« Reply #76 on: 09/21/2015 01:15 AM »
So If SLS were flying dozens of times per year the incremental cost of one additional flight might not vary much, and thus there might be a useful value to call the "marginal cost." But I would expect the incremental cost of a second flight in a given year to be different than the incremental cost of a third flight in that same year.

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

Offline MarcAlain

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Re: SLS General Discussion Thread 2
« Reply #77 on: 09/21/2015 01:49 AM »
So If SLS were flying dozens of times per year the incremental cost of one additional flight might not vary much, and thus there might be a useful value to call the "marginal cost." But I would expect the incremental cost of a second flight in a given year to be different than the incremental cost of a third flight in that same year.

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

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?

Online Brovane

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Re: SLS General Discussion Thread 2
« Reply #78 on: 09/21/2015 01:51 AM »

Apples to oranges.  Unless you're trying to tell me that the Delta IV Heavy price is pure marginal cost, with all fixed costs including supplier fixed costs shoved off onto the DoD...


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.

So for the Delta-IV heavy you have 3xR-68A engines and a RL-10 engine. 

The SLS is 4xRS-25 engines, 2xSRB plus whatever engines are on the upper core.  There is no way that you are getting that hardware for less cost than the Delta-IV Heavy hardware.  A R-68A is less than 1/2 the price of a RS-25 engine.  NASA working with AJR might get that price down further but the RS-25 unit price is not going to get itself below the price of a RS-68A. 

Yes, all the fixed costs of the Delta-IV Heavy production are on the DOD under the current EELV contracts under FAR rules.  That is one of the price advantages when a different part of the US government procures a EELV launch vehicle.  Now that could change in the future but that is how it is currently setup.  With the FAR contracting rules that ULA operates under it has to open it's books to the US govt and justify the costs it is charging.  If certain fixed costs have already been meet by US Govt DOD contracts then ULA under law cannot double charge the US govt for those same fixed costs.
"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 Coastal Ron

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Re: SLS General Discussion Thread 2
« Reply #79 on: 09/21/2015 03:32 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.
If we don't continuously lower the cost to access space, how are we ever going to afford to expand humanity out into space?

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