Author Topic: SLS vs STS Comparison/Contrast Capabilities and Economics for NASA Missions  (Read 42319 times)

Offline 93143

  • Senior Member
  • *****
  • Posts: 3054
  • Liked: 312
  • Likes Given: 1
STS marginal cost was not $450M.  I have no idea where NASA got that number.  The actual marginal cost was between $80M and $120M in modern dollars.

SLS marginal cost looks to be about $300M in modern dollars, possibly less.  Fixed costs will be less than STS; based on what we know of SLS and its affordability push, probably a lot less.

Orion at one flight per year is about $700M total program cost.  The only marginal cost estimate I've seen that wasn't an uneducated WAG is $150M, implying about $0.5B in annual fixed costs.

Offline pathfinder_01

  • Senior Member
  • *****
  • Posts: 2074
  • Liked: 271
  • Likes Given: 8
Lobo . . .

THIS is the thread I've been waiting for for years (literally).

I've been lurking for the past few years, but this one's brought me out of hiding.

I, like you, can't believe that the cost profile of SLS would be that much different than STS, which flew (over the last couple of years during ISS final assembly) 3 - 4 times a year.

The 5-seg booster hardware may be a little more expensive per flight (but not much).
The Orion would be analogous to the Shuttle crew compartment.
The reusable STS engines are discarded after each SLS flight, as would be the rocket's guidance systems, etc.
But, if you can comfortably substitute the STS's refurbishment costs with single-flight5 hardware; I don't see much difference . . .  And you get more cargo to orbit for the same cost with the SLS system (even if you don't take advantage of the increased capacity).

The shuttle reused engines, thrust structures, avionics, gyros, oxygen tanks for the crew, the cabin, TPS, thrusters, OMS enigines, APU'S, fuel cells( in the case of Orion solar panels and water tanks..thrown away), wiring, various plumbing and propellant tanks for the thrusters, and Pressurant tanks and possibly a payload in the cargo bay like spacelab, space hab, the MPLM, and if the shuttle had worked as promised LDEF. It reused a lot of stuff that needs to be rebuilt or replaced for SLS\Orion. The cost of refurbishing may have been more than the cost of say buying an ELV flight but it could still be less than the cost of replacing said systems.

It is like comparing a plastic spoon to a metal spoon when you compare the ELV to the shuttle. The shuttle was designed to be reusable. An ELV is designed to be cheap and single use. Just becuase it was more economical to use the plastic spoon for some reason(say a large party where the only thing served is cake and ice cream) does not mean that throwing out the metal spoon like it were plastic is a good idea.
« Last Edit: 09/26/2013 02:11 am by pathfinder_01 »

Offline ChrisWilson68

  • Senior Member
  • *****
  • Posts: 5266
  • Sunnyvale, CA
  • Liked: 4992
  • Likes Given: 6459
STS marginal cost was not $450M.  I have no idea where NASA got that number.  The actual marginal cost was between $80M and $120M in modern dollars.

Try to help me out here.  NASA told us the marginal cost.  You say you have no idea where NASA got that number, but you give a totally different number without citing any reference or reasoning behind it.

Why should we believe you over NASA about the marginal cost of an STS flight?

Offline 93143

  • Senior Member
  • *****
  • Posts: 3054
  • Liked: 312
  • Likes Given: 1
Because the GAO is on my side.

http://www.gao.gov/products/NSIAD-93-115

NASA New Start says that's $77M in modern dollars.

Also, the much more recent CSTS proposals said $1.8B for 5 flights per year and $1.5B for 2.  IIRC the proposals were separated by a couple of years at most.  Do the math.  (Also note the effect on total cost of removing NASA's oversight layer from the equation...)

Also, think.  STS flight rates were 5-6 per year at budgets of $3-4B per year.  Yet we know that the program was mostly fixed cost - I think it was John Shannon who described STS as essentially $3B/year to have and free to use.  If $450M were a true marginal cost, it would have been the bulk of the budget.

According to John Shannon, IIRC, it would have cost ~$200M a month to keep STS in standby mode at end-of-life, or $2.8B to launch six times in a year - again at end-of-life.  Where does 6x$450M fit?
« Last Edit: 09/26/2013 04:01 am by 93143 »

Offline pathfinder_01

  • Senior Member
  • *****
  • Posts: 2074
  • Liked: 271
  • Likes Given: 8
Because the GAO is on my side.

http://www.gao.gov/products/NSIAD-93-115

NASA New Start says that's $77M in modern dollars.

Also, the CSTS proposals said $1.8B for 5 flights per year and $1.5B for 2.  Do the math.  (Also note the effect on total cost of removing NASA's oversight layer from the equation...)

Also, think.  STS flight rates were 5-6 per year at budgets of $3-4B per year.  Yet we know that the program was mostly fixed cost.  If $450M were a true marginal cost, it would have been the bulk of the budget.

According to John Shannon, IIRC, it would have cost ~$200M a month to keep STS in standby mode at end-of-life, or $2.8B to launch six times in a year - again at end-of-life.  Where does 6x$450M fit?

This is an estimate based in 1993 about flights that never occurred(1994-1997) did not have 8 or 9 flights a year. There were only about 6-7 each year on average with only 1997 having 8. The cost of deleting a shuttle mission is listed as 44.4 million but that says nothing about the cost of adding one(i.e. that 44 million could just be mostly overtime work) and it states that fixed costs are 90% of the costs of the shuttle program.  Here is a very relevant quote:

“For example, eliminating a single flight in fiscal year 1993 may allow NASA to avoid the cost of labor directly involved in the manufacture, inspection, and test of an external tank; the hardware and materials used in manufacturing the tank; and the expense of shipping the tank from the manufacturing site near New Orleans to the launch site at the Kennedy Space Center. However, for NASA to maintain the capability to manufacture up to nine tanks a year, it cannot avoid other labor costs such as those associated with production and industrial engineering, plant maintenance and operations, contract management, finance, planning, or personnel”

In other words the fixed costs eat a lot of the budget.

Offline 93143

  • Senior Member
  • *****
  • Posts: 3054
  • Liked: 312
  • Likes Given: 1
This is an estimate based in 1993 about flights that never occurred(1994-1997) did not have 8 or 9 flights a year

The 8-9 flights per year is the system capacity, not the actual flight rate; they didn't quite use it all, but that's largely irrelevant for our purposes.

Quote
In other words the fixed costs eat a lot of the budget.

Exactly.  STS was mostly fixed cost.  The cost of actually using it was quite small compared to the cost of having it available to use.  This is well known.

It's also not at all consistent with a $450M marginal cost per launch.  Besides which, it's not apparent to me that NASA ever claimed their $450M figure was a marginal cost:

http://www.nasa.gov/centers/kennedy/about/information/shuttle_faq.html#10

Everything else says the marginal cost was much smaller.  So that's what I believe.
« Last Edit: 09/26/2013 04:27 am by 93143 »

Offline pathfinder_01

  • Senior Member
  • *****
  • Posts: 2074
  • Liked: 271
  • Likes Given: 8

Everything else says the marginal cost was much smaller.  So that's what I believe.

Marginal costs based on different assumptions than SLS. For instance you did not buy a new set of engines for the shuttle each flight. They were good for 5 flights, you simply slowed down the maintence if you needed fewer flights. From the document they had over produced external tanks and so had the plan running on min. capcity of 4 tanks a year(so if you needed more than 4 and were out of spares and your costs would increase).

You didn't have to build a new thrust structure, purchase new avionics, gyros, capsule, fuel cells, plumbing, thrusters, propellant tanks for thrusters, and huge amounts of stuff you simply slowed down the maintence. Big diference and low marginal costs are what we would expect from an resuable system.
« Last Edit: 09/26/2013 04:40 am by pathfinder_01 »

Offline ChrisWilson68

  • Senior Member
  • *****
  • Posts: 5266
  • Sunnyvale, CA
  • Liked: 4992
  • Likes Given: 6459
http://www.gao.gov/products/NSIAD-93-115

In other words the fixed costs eat a lot of the budget.

Exactly.  STS was mostly fixed cost.  The cost of actually using it was quite small compared to the cost of having it available to use.  This is well known.

It's also not at all consistent with a $450M marginal cost per launch.  Besides which, it's not apparent to me that NASA ever claimed their $450M figure was a marginal cost:

http://www.nasa.gov/centers/kennedy/about/information/shuttle_faq.html#10

Everything else says the marginal cost was much smaller.  So that's what I believe.

Thanks for the link to that report.  It's very informative.  What this report says is that there's a big difference between short-term fixed costs and medium-term fixed costs.

An analogy would be with a railroad.  Let's say this particular railroad runs 10 trains a day.  You ask what the railroad can save by cancelling one of the trains for one day.  The railroad still has to pay the crew and everyone else involved, still has to pay for the locomotive and the rolling stock even if they are idle for one day.  All the railroad saves is the fuel for that day, which is a small part of their costs.  So, you would say their marginal costs to run the train are very low, say 1%.

On the other hand, if you ask what the railroad can save by permanently cutting down their schedule from 10 trains to 9 trains a day, the answer is quite different.  They can cut the number of engineers, conductors, maintenance workers, etc. by 10%.  They can cut the number of locomotives by 10%.  They can cut the number of passenger cars by 10%.  There are still some centralized functions they need, like the headquarters costs, so they don't cut all costs by 10%.  But they might cut total costs by 8%.

So, if people are arguing about whether the marginal cost of running a train is 1% or 8%, they'd both be right, but on different time scales.

It seems that's the difference between the $450 million and $77 million marginal costs for STS.  If they continued to maintain the ability to launch at a rate of 5-6 a year, cutting one flight would save around $77 million.  But, if they permanently downsized to only have the ability to launch 4-5 times a year, the savings would be $450 million a year eventually after the close-out costs.

In fact, the GAO report says there was a disagreement between NASA and the GAO about whether to use the short-term marginal cost numbers or the medium-term marginal cost numbers for assigning costs for some proposed future flights.  The GAO was arguing the medium-term number was appropriate and NASA was arguing the short-term number was appropriate.

So, getting back to SLS, what lesson does this give us for SLS?  Well, the plans are to gear up to have the capacity to build and launch one SLS every two years.  If you decide not to launch in one two-year period, you don't save much.  But, if you want to gear up to be able to launch once or twice a year, the cost is probably much higher -- perhaps $450 million per additional launch.

Offline 93143

  • Senior Member
  • *****
  • Posts: 3054
  • Liked: 312
  • Likes Given: 1
pathfinder_01, I'm not sure who you think you're arguing with.  I know all that.

ChrisWilson68, I know that too.  Part (but by no means all) of NASA's affordability push with SLS is the low flight rate specification; it allows them to keep fixed costs down until such time as the budget starts to look more reasonable (if that ever happens, which it may).  But if you're going to calculate marginal cost like that, you'll probably end up with a much lower fixed cost, and the combination could be misleading.  And I'm not sure anyone here really has an idea of what the difference would actually be...

Like I said above, I don't think NASA ever claimed their $450M number was a marginal cost.  What makes you think it is, other than that it seems to fit your theory?  Note that it's also very close to what was the target for (IIRC) 2010:  6 launches for about $2.8B total program cost...

...

I'm not claiming that SLS will have the same cost profile as STS.  We don't have a ton of data, but we have enough that I don't need to do that.

Take a look at the ESD Integration budget availability report.  (And keep in mind that this is based on legacy STS and CxP cost figures; tech improvements and management/oversight leaning should bring the numbers down.)  Case #4 has two scenarios, which after 2023 are identical except for an extra Block 1 SLS launch per year.  Development is finished by that point for SLS, MPCV, and 21st CGS, and ops appear to be in steady state, so costs can be compared.

The difference is slightly more than $300M in modern dollars for SLS and about $11M for 21st CGS.  This should, at the very least, constitute an upper bound on the estimated short-term marginal cost.  MPCV is identical, but then its launch rate is identical.  (It isn't clear to me why exactly the SLS fixed cost (about $1.6-1.7B or so in modern dollars, or $2.1B with ground systems included) seems to be so much larger than in Cases #1 and #2 where ongoing development is occurring, so I haven't tried to prove anything about fixed costs.  But from the first two Cases it seems to me that at one flight per year the fixed cost need not be as high as $1B in modern dollars (~$1.3-1.4B with ground systems), before affordability measures.)

Compare with this chart, describing a slightly smaller SDLV with Shuttle-heritage infrastructure:

http://forum.nasaspaceflight.com/index.php?topic=18752.msg622582#msg622582
« Last Edit: 09/26/2013 09:01 am by 93143 »

Offline Robotbeat

  • Senior Member
  • *****
  • Posts: 39270
  • Minnesota
  • Liked: 25240
  • Likes Given: 12115
The assumptions behind the old DIRECT numbers are not laid bare. Aren't helpful.
Chris  Whoever loves correction loves knowledge, but he who hates reproof is stupid.

To the maximum extent practicable, the Federal Government shall plan missions to accommodate the space transportation services capabilities of United States commercial providers. US law http://goo.gl/YZYNt0

Offline Lobo

  • Senior Member
  • *****
  • Posts: 6915
  • Spokane, WA
  • Liked: 672
  • Likes Given: 437
Lobo . . .

THIS is the thread I've been waiting for for years (literally).

I've been lurking for the past few years, but this one's brought me out of hiding.

I, like you, can't believe that the cost profile of SLS would be that much different than STS, which flew (over the last couple of years during ISS final assembly) 3 - 4 times a year.

The 5-seg booster hardware may be a little more expensive per flight (but not much).
The Orion would be analogous to the Shuttle crew compartment.
The reusable STS engines are discarded after each SLS flight, as would be the rocket's guidance systems, etc.
But, if you can comfortably substitute the STS's refurbishment costs with single-flight5 hardware; I don't see much difference . . .  And you get more cargo to orbit for the same cost with the SLS system (even if you don't take advantage of the increased capacity).

The shuttle reused engines, thrust structures, avionics, gyros, oxygen tanks for the crew, the cabin, TPS, thrusters, OMS enigines, APU'S, fuel cells( in the case of Orion solar panels and water tanks..thrown away), wiring, various plumbing and propellant tanks for the thrusters, and Pressurant tanks and possibly a payload in the cargo bay like spacelab, space hab, the MPLM, and if the shuttle had worked as promised LDEF. It reused a lot of stuff that needs to be rebuilt or replaced for SLS\Orion. The cost of refurbishing may have been more than the cost of say buying an ELV flight but it could still be less than the cost of replacing said systems.

It is like comparing a plastic spoon to a metal spoon when you compare the ELV to the shuttle. The shuttle was designed to be reusable. An ELV is designed to be cheap and single use. Just becuase it was more economical to use the plastic spoon for some reason(say a large party where the only thing served is cake and ice cream) does not mean that throwing out the metal spoon like it were plastic is a good idea.

Pathfinder & Mike D.

Mike, you itterated some of my thoughts and questions.

Pathfinder.
A few issues with your examples.  This is how I understand it and if I'm incorrect, I'm certainly happy to be corrected.

1)  SSME's:  I've often heard that the refurbishment of the RS-25's was so costly that it would have been as cheap, or perhaps cheaper, to have gone with an expendable engine from the start, like the RD-0120.  Or had an RS-25E from the jump.  Part of that is that since the RS-25's didn't have an infinite service life, Rocketdyne still needed to maintain a production facility for new engines, as well as refurbishment facilities to reprocess used engines (it was probably one facility that could do either).  A major problem with that is the production rate of new engines was so low, that over 30 years, they wasn't very many major improvements in the production process to make use of new automation.  So 30 years later new RS-25's were still being made in a very labor-intensive, hands-on way that they were in the 70's.  It doesn't make much sense to completely renovate your facility for just a few new production engines a year.  So the cost of new engines stayed very high, as was the cost of reprocessing of engines.  A "mass-produced" low cost engine like an RD-0120 at first, or an RS-25E now would have been as cheap if not cheaper.
So the fact the Shuttle reused it's engines I don't think was any cost savings vs. SLS expending them.

2)  SRB's:  I've heard from many sources that the cost of recovering and reusing the Shuttle 4-seg SRB's was about a push with the cost of making new ones.  So the fact the shuttle reused them didn't save any money.  Now, if Ares 1 and Ares 5 had flown, there might have been a case to say the new 5-segs were 20% more expensive because of the extra segment.  That's not nothing, but it's not a very large expense I don't think.
Here's the difference with SLS.  As I understand, now all of the tooling that made those steel casings has been scrapped.  ATK has enough casings on hand to make 10 pairs of 5-seg boosters.  And then either new steel casing tooling needs to be built (which has a certain expense), or composite casing casting equipment needs to be built (with it's expense), or liquid boosters need to be built (with it's expense).
But the point is, I don't think for SLS, we can say the 5-seg boosters will cost any more per unit, or per year, or whatever, tahn the 4-seg boosters.  We don't know.  ATK would very much like to sell all 10 pairs, rather than just two pairs as some potential SLS plans call for advanced booster upgrades after just two SLS flights.  I've heard that ATK made NASA a very attractive offer on all 10 pairs.  The extra 8 pairs would do them no good to keep, so there's a reasonable chance that they could be fairly cheap...just to sell them and keep ATK's facility and people employed for awhile longer.  HAving SLS stick with 5-seg boosters for 10 launchs might help ATK's case for composite boosters as they will likely be a much easier transition than liquid boosters in the infrastructure.  Another reason ATK could offer all 10 pairs of 5-seg boosters at a prices that could be as cheap as the 4-seg.  I don't know.  But I'm assuming if they are an "attractive price", they aren't simply 20% more expensive than the expensive Shuttle boosters.  I don't think that would be all that "attractive"

3.  Various other reused items vs. expended.
"thrust structures, avionics, gyros, oxygen tanks for the crew, the cabin, TPS, thrusters, OMS enigines, APU'S, fuel cells"
Thrust structures were resused...but they are expended for every other LV flying currently.  I don't think they are a major cost factor on Falcon or Atlas by themsleves.
Same with avionics and the rest.
If SpaceX wins CRS, they will have to supply a brand new Dragon for each crew mission.  That means a new capsule with new TPS, RCS/OMS engines, tankages, structures, computers, avionics, etc.  Much of what Dragon will need to support a crew, the Shuttle needed too, just at a difference scale.  And I'm pretty sure Dragon will just be a small percentage of the cost to reprocess an orbiter.  Orion will be more expensive than Dragon for two main reasons.  First it's BLEO capable and the current Dragonrider in development won't be.  Second, Orion carries all of the overhead of oldspace, and thus will always be more expensive than newspace.  But the Shuttle did too.  And my main point here is expendable can be much cheaper than reusable, as Dragon will likely be much cheaper than an STS processing. 
Also note the reused TPS system on the shuttle was no cost saver vs. an expendable TPS on a capsule.  As I understand each tile needed to be inspected and replaced if damaged between flights.  And it was a very expensive and labor intensive process.  As opposed to the fabrication of a new Orion or Dragon heat shield.

4.  SLS core vs. STS ET.  I think once it's developed, the SLS core will be cheaper to make because of the new tooling that's supposed to highly automate the process.  The SLS core facility will have a much smaller work force as well.  It'll also use AL2219 rather than AL2195 is which easier to fabricate with as I understand, and cheaper.  (although the cost of the metal is probably negligible)
There will be a new MPS on each core, where STS reused it's MPS on shuttle.  So, while the SLS core is probably cheaper, maybe the MPS added enough cost to make it roughly even with the STS ET.   
The ET was called just a "tank", but it really was a whole rocket core itself which had thrust structures and plumbing and everything a rocket core has other than the MPS itself.  But they did have to go through and inspect the Shuttle MPS betewen flights, so it's reuse wasn't without cost.  And I don't think F9's new octoweb MPS is a very expensive item into itself?

So, theoretically, there's a reasonable case to be make (I think) that an SLS block 1 by itself won't be super expensive.  Perhaps much cheaper than STS.  If you want to launch a crew, then you need to add Orion and that adds cost.  Orion's probably a lot more expensive than it really needs to be given all of it's legacy cost. 
Adding a DUUS will add cost too, although if it's built at MAF using the existing SLS core and A1US tooling, and sharing systems with DCSS/ICPS, it might not be all of that expensive to make once it's developed.  In reading the recent article here on SpaceX's Falcon and Dragon "nursery", Elon makes a comment that the Falcon upper stage is basically a shorter version of the Falcon core for commonality.  The DUUS would actually be much like that too.  The LH2 tank would use all the same barrel and dome tooling as the core.  The LOX tank will use the A1US tooling (or DCSS 5m tooling).  The interestage adaptor will likely use the same tooling as well. 

Anyway, the reusability of the Shuttle I don't think was ever a money saver in reality (as they hoped it would).  At best, perhaps a push with a similar expendable system (something like Jupiter 130 with an evolved Apollo caspule instead of STS in the 70s for example, and using fully expendable booster and engines).  Hence my theory that SLS really won't be any more expensive to maintain and fly than STS was.  And while Orion is expensive and perahps SLS + Orion would be more expensive for an average launch than STS, SLS can fly without Orion.  As would be the case for a two launch lunar architecture.  You aren't necessarily paying for Orion on every SLS flight, but you -were- paying for an oribter and risking a crew for every STS flight.  Even missions where having a crew really accomplished nothing, like satellite payload missions.  And I don't think paying for an expendable PLF vs. the inspection and possible repair of the Shuttle PLB between each flight is much of a difference. 

And as to Pathfinder's analogy about plastic vs. metal spoons, note that there is a reason they make plastic spoons.  When you occasionally need to use them, say once or two a year, you can buy a lot of plastic spoons before you've paid for a whole set of nice metal flateware.  Especially if you are using them somewhere where it's difficult to bring them back and wash them all.
If you are using your flatware every day in your house right next to your dishwasher where it's easy/cheap to clean (process), then yea, the more expensive reusable metal flatware makes a lot of sense and pays for iteself.  That was the idea for STS.  Instead it was just used hisotircally about 4.5 times per year and never really paid for itself vs. just using plastic those occasional times.

:-)


 

Offline Lobo

  • Senior Member
  • *****
  • Posts: 6915
  • Spokane, WA
  • Liked: 672
  • Likes Given: 437

This is an estimate based in 1993 about flights that never occurred(1994-1997) did not have 8 or 9 flights a year. There were only about 6-7 each year on average with only 1997 having 8.

There were 135 STS flights over 30 years (1981-2011).  So about 4.5 launches each year average over the life of the program. 

Offline Lobo

  • Senior Member
  • *****
  • Posts: 6915
  • Spokane, WA
  • Liked: 672
  • Likes Given: 437

Exactly.  STS was mostly fixed cost.  The cost of actually using it was quite small compared to the cost of having it available to use.  This is well known.


Yes, exactly my point and question with this thread.

Won't this be roughly the case with a "shuttle-derived" system like SLS?  Won't the costs be mostly fixed too?

Won't they mainly be the cost of KSC operations (which should be reduced from STS days), the cost of the SLS cores at MAF (which should also be reduced from STS days) the cost of 10 pairs of 5-seg SRB's, and the cost of maintaining the Rocketdyne production line for the RS-25E?  Add in the cost of the Orion production line.  All of that will need to be paid for regardless of if they are doing anything or sitting on their thumbs.  Which was the case with STS, hence those quotes by John Shannon above. 

If that won't be the case for SLS, I'm curious as to why not.

 

Offline Go4TLI

  • Full Member
  • ****
  • Posts: 816
  • Liked: 96
  • Likes Given: 0
Won't this be roughly the case with a "shuttle-derived" system like SLS?  Won't the costs be mostly fixed too?


It has nothing to do with it being "shuttle-derived".  Everything sufficiently complex and with high performance will have generally higher fixed cost than recurring cost.  It's the nature of the game in order to keep facilities and infrastructure operational, supply lines available and personnel trained and qualified. 

Let's take everyone's favorite example, SpaceX.  If they stood down from launch/flight operations completely for a year they would still have a cost to keep everything, and everyone, going. 

Offline Lobo

  • Senior Member
  • *****
  • Posts: 6915
  • Spokane, WA
  • Liked: 672
  • Likes Given: 437
Won't this be roughly the case with a "shuttle-derived" system like SLS?  Won't the costs be mostly fixed too?


It has nothing to do with it being "shuttle-derived".  Everything sufficiently complex and with high performance will have generally higher fixed cost than recurring cost.  It's the nature of the game in order to keep facilities and infrastructure operational, supply lines available and personnel trained and qualified. 

Let's take everyone's favorite example, SpaceX.  If they stood down from launch/flight operations completely for a year they would still have a cost to keep everything, and everyone, going.

Ok, good clarification.

But the point remains, won't SLS be pretty similar in it's large fixed cost vs. smaller marginal cost the way STS was?
If for no other reason than it's a big, complex, and expensive government program...which usually have very high overhead compared to what's actually put out?
;-)

Offline Lobo

  • Senior Member
  • *****
  • Posts: 6915
  • Spokane, WA
  • Liked: 672
  • Likes Given: 437

So, getting back to SLS, what lesson does this give us for SLS?  Well, the plans are to gear up to have the capacity to build and launch one SLS every two years.  If you decide not to launch in one two-year period, you don't save much.  But, if you want to gear up to be able to launch once or twice a year, the cost is probably much higher -- perhaps $450 million per additional launch.

I suppose it really depends on what SLS is -really- being designed to produce.  Is it really one every other years?  There are proposals that call for 1 launch a year and 2 launches a year (the report linked ealier in this thread) depending on funding. 
I believe NASA's mentioned soemwhere KSC needs to be able to launch an SLS every 120 days, which is 3 a year.

3 launches per year seems much more likely to be the target number with the infrastructure they are putting in place as a maximum capacity than 0.5 per year.  (That could also support a Mars Semi-Direct plan per Zubrin).   To only be planning for one launch every other year, and needing a lot of extra money to do more than that, seems -very- limiting and a complete reverseal of NASA's normal tendancy to be much too optimistic about flight rates. 

My guess (and this is just a guess) is that the infrastructure being laid down is adequate to support anything from 0.5 launches per year to at least 2 launches per year (maybe 3) with little actual change or additional cost.  0.5 launches a year would keep the workforce in place working at a minimal rate, and 2-3 launches per year would keep them working at a more productive rate, but still within the capabilities of your workforce.  The infrastructure and workforce being put in place will have those as their minimum and maximum capacity.  More than 2-3 SLS's per year (if there was ever need or budget), and then maybe more expensive expansions.  More work force, more shifts, maybe outfiting an extra VAB high bay for SLS, a 2nd mobile launcher, etc.

That's probably what I'd be designing for anyway.  And with new automation, that should be pretty doable.  Once you've paid for the new automation and tooling, then it really doesn't cost you any more whether it's punching out 1 widget every 2 years, or 3 widgets in a year, as long as it's within it's designed operational capacity.  It's cost and overhead are the same regardless.
And that's pretty much the case with any production.  They usually have a minimum and maximum capacity.  In a commercial market, how many widgets they make is dictated by sales.  Less than a minimum number, and you aren't putting out enough to pay for the overhead you have standing around and loose money or have to fire people.  More than a maximum number, and you have to start running overtime, or hire additional people and buy additional equipment.  You have a certianly range of flexibility between those two points. So I'm hoping that's the case here for SLS.  :-)

« Last Edit: 09/26/2013 06:13 pm by Lobo »

Offline ChrisWilson68

  • Senior Member
  • *****
  • Posts: 5266
  • Sunnyvale, CA
  • Liked: 4992
  • Likes Given: 6459
My guess (and this is just a guess) is that the infrastructure being laid down is adequate to support anything from 0.5 launches per year to at least 2 launches per year (maybe 3) with little actual change or additional cost

There's no need to guess.  NASA has said.  They plan to set up everything to support 0.5 launches a year.  Not 2.  Not 3.  0.5.

Offline 93143

  • Senior Member
  • *****
  • Posts: 3054
  • Liked: 312
  • Likes Given: 1
That's production.  Launch infrastructure is being set up to do 3.

Production facilities and staffing levels could easily be upgraded if the government stumps up the cash; it's not a question of SLS itself being "designed" to launch once every two years.  A few production processes are being optimized for "low" flight rates, but I don't imagine there's a hard limit anywhere near the current production requirement.

Besides, NASA has also stated that they expect the final version to eventually launch one or two times a year.  They also said it would probably cost about $500M per launch at one per year, but as with the $450M number for STS it's not quite clear what that means, or even whether it's in current-year or then-year dollars...
« Last Edit: 09/26/2013 09:25 pm by 93143 »

Offline Lobo

  • Senior Member
  • *****
  • Posts: 6915
  • Spokane, WA
  • Liked: 672
  • Likes Given: 437
That's production.  Launch infrastructure is being set up to do 3.


Yea, that's what I recall hearing for KSC.  One launch every 120 days minimum turn around time.  I'm guessing that assumes just the one mobile launcher, so after a launch, there's rollback, ML refurb, stacking of the new LV and payload integration, and then roll out to the pad with a 2 week on pad stay, and launch again within 120 days. 
(Although, I would think that could be cut way down if there was a 2nd ML constructed, and if enough VAB room was allocated for stacking of two SLS's at the same time.  Then the time between launches could be cut down to about 2 weeks.  This wouldn't increase the overall annual launch probably, but could allow for a two launch mission to occur without the first payload having to loiter for 120 days.  But it's all money, payloads, and politics if that would happen.)


Production facilities and staffing levels could easily be upgraded if the government stumps up the cash; it's not a question of SLS itself being "designed" to launch once every two years.  A few production processes are being optimized for "low" flight rates, but I don't imagine there's a hard limit anywhere near the current production requirement.

Besides, NASA has also stated that they expect the final version to eventually launch one or two times a year.  They also said it would probably cost about $500M per launch at one per year, but as with the $450M number for STS it's not quite clear what that means, or even whether it's in current-year or then-year dollars...

That was my thought, although you said it better than I.  I'd find it rather unusual if all the new FSW automated tooling couldn't do more than 0.5 cores per year if there was need.  Maybe it would take some more people to opperate that. Or it just might mean the existing staff fits it within their existing staffing capacity.  But I'd be real surprised if there wasn't a 2-3 SLS core per year capacity before major changes/investments would be needed to increase.  Even if the intial staffing will be geared towards 0.5 per year.



Offline pathfinder_01

  • Senior Member
  • *****
  • Posts: 2074
  • Liked: 271
  • Likes Given: 8

And as to Pathfinder's analogy about plastic vs. metal spoons, note that there is a reason they make plastic spoons.  When you occasionally need to use them, say once or two a year, you can buy a lot of plastic spoons before you've paid for a whole set of nice metal flateware.  Especially if you are using them somewhere where it's difficult to bring them back and wash them all.
If you are using your flatware every day in your house right next to your dishwasher where it's easy/cheap to clean (process), then yea, the more expensive reusable metal flatware makes a lot of sense and pays for iteself.  That was the idea for STS.  Instead it was just used hisotircally about 4.5 times per year and never really paid for itself vs. just using plastic those occasional times.

:-)

All of the CCREW are aiming for reusability, so it may not have to supply a new dragon. For cargo NASA requires a new dragon but I wouldn’t be surprised if Space X used a reusable cargo dragon when available and renegotiates  the contract or offers it for an second round of cargo delivery.  As for thrust structure ect, all of that will have to be rebuilt and if you are using shuttle technology, you are using technology that was inherently designed for reuse else you are just pulling everyone’s leg about how “shuttle” derived it is and those changes combined with NASA’s already high overhead will make this thing likely more expensive than the shuttle was. 

Also EELV try to have as much cost savings built in as possible. Orbital and Atlas use engines that other rockets were use or planning to use. Space X uses the same engine just about on 1st and 2nd stage.  The RL-10 has powers upperstages for both Delta and Atlas and Delta and Atlas are moving towards shared avionics. Shuttle derived shares just about nothing with any other rocket. SLS itself only plans to use the DDCS because they don’t have time to design a 2nd stage otherwise it would  be something J2 powered. This will do nothing but keep costs high as this workforce is separate from other workforces.

Also like the plastic spoon, this rocket will not be made in any large numbers because NASA HSF must pay for each unit. Atlas, Delta, Falcon 9, and even FH have other users to share overhead costs.

Tags:
 

Advertisement NovaTech
Advertisement Northrop Grumman
Advertisement
Advertisement Margaritaville Beach Resort South Padre Island
Advertisement Brady Kenniston
Advertisement NextSpaceflight
Advertisement Nathan Barker Photography
0