Author Topic: Reuse business case  (Read 318508 times)

Offline Lemurion

Re: Reuse business case
« Reply #440 on: 05/11/2016 05:38 pm »
If I had to bet on it, I'd say that SpaceX flying at least one reused booster is a near certainty


An opinion based on little to no data.

After all, Grasshopper, the F9R, and New Shepard have proven the principle of rocket reusability. Liquid fueled rockets can be refueled and reflown.


None of those went through entry heating.  Also, you forgot DC-X and the shuttle.

I thought about DC-X, but figured 3 recent examples were enough.

As for the entry heating and data issues, I would say that while there's not a lot of data, there is at least some data from which to draw conclusions at least in principle.

We know that a stage can survive entry heating, and that it can perform a controlled burn afterwards without refurbishment because that's a requirement for a successful propulsive landing. The stage structure itself was also able to survive the landing loads. The post-landing test fire is further proof of principle that the engines can be used after surviving entry.

Yes, I'm aware that there were thrust fluctuations, but the fact they were able to do it at all is proof of principle. If it were impossible, none of the engines would have functioned properly.

We also know from test fires that the Falcon 9 booster can be refueled, and in at least one case even after recovery.

Ignoring the amount of refurbishment required for the moment as that's as much an economic question as a technical one; reusing a stage requires that it be refueled and then make a controlled burn. SpaceX has essentially already done everything they would need to do to reuse a stage, just not to the same degree.

Going for a full stage reuse involves more of the same, rather than something entirely new. They may need to increase the thermal protection, they may need to tweak other elements that I'm not aware of, but they have the basics.

Propulsive landing is proof of principle for stage reuse.

Offline jongoff

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Re: Reuse business case
« Reply #441 on: 05/11/2016 05:53 pm »

Jim, as of right now, based on what you know, what do you personally think the probability is that SpaceX will fly at least one reused booster at some point? And what do you think the conditional probability of success is, given that they fly one?

An educated guess based on little to no data (but arguably more than most of us have) from you would be interesting.


From what I saw, the aft end needs much more protection.  There were panels that were damaged and opened on the previous booster.  The fires on the current booster may have been internal.   

While I agree with you that they haven't *yet* recovered a booster in a condition to refly it, as they get more data do you really think they can't make modifications to eliminate those issues and get a booster back in good enough condition to fly? I'm not seeing any showstoppers to eventually having something they can reuse at least a small number of times. It will probably take them longer than the amazing peoples expect, and the performance hit necessary for all the features they'll need for reuse may be more than currently expected, but I'd be really surprised if they couldn't figure it out eventually (with eventually being in the 1-2yrs range).

Now, getting Falcon 9 to their mythical 100x reuse level? I'm skeptical as heck about that. But reusing it enough to allow them to offer non-trivial price reductions? That seems pretty likely to me.

~Jon

Offline Jim

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Re: Reuse business case
« Reply #442 on: 05/11/2016 05:53 pm »

Propulsive landing is proof of principle for stage reuse.

Not true at all.  See any planetary lander.

The stage structure itself was also able to survive the landing loads.

Survive and reuse are two different things.  And also, reuse and cost savings are two different things.


Ignoring the amount of refurbishment required for the moment as that's as much an economic question as a technical one;

That's the point.  It is a economic question.  They could have done it already with no real payload and made the entry of the stage even more benign.  And done the reflights with that.

I think there will be no "gas and go" and refurb will always be needed and will be no where close to the savings predicted.


« Last Edit: 05/11/2016 06:05 pm by Jim »

Offline Jim

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Re: Reuse business case
« Reply #443 on: 05/11/2016 05:55 pm »

Now, getting Falcon 9 to their mythical 100x reuse level? I'm skeptical as heck about that. But reusing it enough to allow them to offer non-trivial price reductions? That seems pretty likely to me.


I believe what they have done up to this point on the design and operation of the vehicle without reuse is a larger impact to the cost of the vehicle than what they will get out of reuse.

Offline Lemurion

Re: Reuse business case
« Reply #444 on: 05/11/2016 06:40 pm »

Propulsive landing is proof of principle for stage reuse.

Not true at all.  See any planetary lander.

The stage structure itself was also able to survive the landing loads.

Survive and reuse are two different things.  And also, reuse and cost savings are two different things.


Ignoring the amount of refurbishment required for the moment as that's as much an economic question as a technical one;

That's the point.  It is a economic question.  They could have done it already with no real payload and made the entry of the stage even more benign.  And done the reflights with that.

I think there will be no "gas and go" and refurb will always be needed and will be no where close to the savings predicted.




I don't see "gas and go" coming immediately if at all. As to the amount of savings, that depends on the degree of refurbishment and we don't have enough examples for numbers on that. However, if they are capacity constrained as has been argued, then the economics may change again in reuse's favor as it would act as a production multiplier giving the capacity to sell more flights than they would otherwise be able to produce launchers for.

But that's another question.

As for proof of principle: SpaceX has demonstrated that a stage is capable of powered maneuvers after entry. That's the basics of reuse.

Offline spacenut

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Re: Reuse business case
« Reply #445 on: 05/11/2016 07:13 pm »
To me, SpaceX is going to have to check the entire booster for stresses.  Not just engines, but legs, the structure itself, internal components.  Worse case scenario is they will not be able to reuse the booster, but just some of the engines, and maybe a few other components.  However, even if they can't reuse it but one time, it would cut launch costs on the second launch.  Hopefully they can reuse them about 10 times or more.  This may take a while. 

Offline meekGee

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Re: Reuse business case
« Reply #446 on: 05/11/2016 07:21 pm »
Dr. Sowers presented the case, and made assumptions about SpaceX in his model, which he stated as such. He identified them by name.



Very true, good point. The concern with SpaceX is competitive, that is, how likely will it be that they actually reduce the cost of flight by a significant factor, which would put additional competitive pressure on ULA? In a way even that is moot, since SpaceX already outcompetes ULA on price, despite possibly wasting money on resue efforts that may not pan out. Imagine if they didn't spend any effort on reuse, how cheap would they be then? If the answer is not that much cheaper, it shows how feasible their reuse efforts are since they were able to "bake them in" to a market leading competitive structure.

Dr. Sowers'  assumptions with regard to SpaceX do not seem to acknowledge that and were not based on hard evidence,  since that is proprietary. So in effect, even though he attempted to make the case against reuse on SpeceX behalf, it is not very a strong case, and looks like an attempt to sooth ULA's (and their owners/shareholders) concerns.

The spreadsheet, as attached, was configured to arrive at a conclusion that RTLS never ever makes sense.

Sure, there was a disclaimer, but the disclaimer didn't say that the conclusion is extremely sensitive to input parameters that are anyone's guess, such as the HW cost fraction relative to the entire mission cost, which is so ill defined it's not even inaccurate.

After that people propagate the conclusion, citing the spreadsheet as the basis for their logic, and a "fact" is born.
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Offline Space Ghost 1962

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Re: Reuse business case
« Reply #447 on: 05/11/2016 08:44 pm »

Jim, as of right now, based on what you know, what do you personally think the probability is that SpaceX will fly at least one reused booster at some point? And what do you think the conditional probability of success is, given that they fly one?

An educated guess based on little to no data (but arguably more than most of us have) from you would be interesting.


From what I saw, the aft end needs much more protection.  There were panels that were damaged and opened on the previous booster.  The fires on the current booster may have been internal.   

While I agree with you that they haven't *yet* recovered a booster in a condition to refly it, as they get more data do you really think they can't make modifications to eliminate those issues and get a booster back in good enough condition to fly? I'm not seeing any showstoppers to eventually having something they can reuse at least a small number of times. It will probably take them longer than the amazing peoples expect, and the performance hit necessary for all the features they'll need for reuse may be more than currently expected, but I'd be really surprised if they couldn't figure it out eventually (with eventually being in the 1-2yrs range).

Jim didn't answer Lar's questions, but provided trusted insight instead. Agree with Jon on all he said, answering part of Lar's questions.

Would like to point out that all of the structural concerns for recovered boosters as well as most of the retropropulsion plume impingement issues seem to have gone by the wayside.

Jim's observations/concerns are about a very specific area of the vehicle, which can be addressed in different ways.

In addition, I'll add that we've not been hearing about hotfires, so engine issues are also on my "hot list"  8)

Lar, from Jim/Jon's/mine's observations, the reflight IMHO of a stage will have as high a degree of success as the original flight or better. But Musk likely won't rush to prematurely fly a reflight, and the question you should be asking is "does he redesign or does he reprocess/remediate stages/engines?". E.g. do we have a step in this where "non aircraft operations" (which are likely to NOT be economic reuse) occurs, as a step along the path to "aircraft like operations".

Plain (heh) and simple, the dog that caught the bus isn't set up (right handling, right flight systems/vehicle, right CONOPs, ...) to do what he says he'll do.

Quote
Now, getting Falcon 9 to their mythical 100x reuse level? I'm skeptical as heck about that. But reusing it enough to allow them to offer non-trivial price reductions? That seems pretty likely to me.

I'm not so skeptical, just this isn't the vehicle that will do it. Yes they can launch cheaper, the question is enough cheaper to matter?


Propulsive landing is proof of principle for stage reuse.

Not true at all.  See any planetary lander.
LM? Proposed "hoppers"?

Quote
The stage structure itself was also able to survive the landing loads.

Survive and reuse are two different things.  And also, reuse and cost savings are two different things.
Structure that can be reused likely has additional structural margin, if reused a lot, then quite a lot.

Is saving this economic or not? Has to prove itself. Hasn't with Shuttle.

Quote

Ignoring the amount of refurbishment required for the moment as that's as much an economic question as a technical one;

That's the point.  It is a economic question.  They could have done it already with no real payload and made the entry of the stage even more benign.  And done the reflights with that.
Absolutely. Am wondering why they did not - were they stopped by economics already, or do performance "ambitions" factor in here.

Quote
I think there will be no "gas and go" and refurb will always be needed and will be no where close to the savings predicted.
Thank you Jim for that candid statement. Precisely what I wonder too.

So the question might be reframed as "Does it require a larger, more capable RLV to achieve 'gas-n-go' operation?". Would that cause Musk to "go slow" here?

Kinda runs counter to Jon's small RLV claims ... ;)


Now, getting Falcon 9 to their mythical 100x reuse level? I'm skeptical as heck about that. But reusing it enough to allow them to offer non-trivial price reductions? That seems pretty likely to me.


I believe what they have done up to this point on the design and operation of the vehicle without reuse is a larger impact to the cost of the vehicle than what they will get out of reuse.

(my highlighting)

So either we haven't "seen it all" yet meaning WIP, or they have built a "gold plated turkey" as POC?

Translation: "not enough" for Lar's post.

« Last Edit: 05/12/2016 12:44 am by Space Ghost 1962 »

Offline jongoff

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Re: Reuse business case
« Reply #448 on: 05/11/2016 10:01 pm »

Now, getting Falcon 9 to their mythical 100x reuse level? I'm skeptical as heck about that. But reusing it enough to allow them to offer non-trivial price reductions? That seems pretty likely to me.


I believe what they have done up to this point on the design and operation of the vehicle without reuse is a larger impact to the cost of the vehicle than what they will get out of reuse.

Hmm... to be honest, I'm not sure whether I agree with this or not. To-date I agree that their design and operations choices have definitely had a larger impact on vehicle cost, and at least near-term that may still be the case. But even without getting into the 100x reuse level, I think they'll get to a point where reuse is making a bigger difference than just their design and operations choices can provide.

~Jon

Offline RocketGoBoom

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Re: Reuse business case
« Reply #449 on: 05/11/2016 10:23 pm »

I believe what they have done up to this point on the design and operation of the vehicle without reuse is a larger impact to the cost of the vehicle than what they will get out of reuse.

Hmm... to be honest, I'm not sure whether I agree with this or not. To-date I agree that their design and operations choices have definitely had a larger impact on vehicle cost, and at least near-term that may still be the case. But even without getting into the 100x reuse level, I think they'll get to a point where reuse is making a bigger difference than just their design and operations choices can provide.

~Jon

The design and operation choices that SX has made so far clearly have not hurt them. They are producing an expendable LV that has morphed into a plausible reusable first stage. Even in full expendable mode SX has a massive cost advantage on their competition.

Are you saying that their quoted price per launch would be perhaps $57 million (full expendable mode) instead of the current $62 million if SX never even bothered with the effort to land the first stage? If their attitude was F9 is a stable platform and they are not doing any more iterations, then overall it would be cheaper?

These numbers seem like rounding errors compared to the prices of their competitors.

In the big scheme of things, it doesn't seem like it has cost SX much to get to this level of capability. I would be shocked if they have spent more than $50 million on the Grasshopper program, the barges, the labor of the landing effort, etc. They got all of the test landings practically for free by using paying customer launches.
« Last Edit: 05/11/2016 10:28 pm by RocketGoBoom »

Offline jongoff

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Re: Reuse business case
« Reply #450 on: 05/11/2016 10:42 pm »
In addition, I'll add that we've not been hearing about hotfires, so engine issues are also on my "hot list"  8)

I've been thinking this too. With how important reuse is to SpaceX's long-term vision, you would think that if everything was going swimmingly they'd be a lot more open about it. That doesn't say they'll never get there, just that their recovery successes are to paraphrase Obi Wan their "first steps into a larger world." At the time of SpaceX's and Blue's first recoveries late last year I wanted to do a blog post about what I thought the path forward might look like. I'm personally pretty optimistic they'll get reuse working to the point where it is a clear economic win, I'm just less clear on if they're really on a path to the most optimistic numbers you hear tossed about ($10M Falcon 9 flights and such).

Quote
I'm not so skeptical, just this isn't the vehicle that will do it. Yes they can launch cheaper, the question is enough cheaper to matter?

I definitely agree that Falcon 9 as is probably is nowhere close to a vehicle that can safely fly 100x. But I'm pretty optimistic they can get a few flights out of each core, and do so in a way that gives a noticeable cost savings.

Quote
Structure that can be reused likely has additional structural margin, if reused a lot, then quite a lot.

Is saving this economic or not? Has to prove itself. Hasn't with Shuttle.

Quote
So the question might be reframed as "Does it require a larger, more capable RLV to achieve 'gas-n-go' operation?". Would that cause Musk to "go slow" here?

Kinda runs counter to Jon's small RLV claims ... ;)

To answer your later question, I think that RLVs capable of high numbers of reflights with gas-n-go operations are possible, they're just going to require living with a lower payload fraction (payload mass to GLOW). So small RLVs are still possible, they're just going to require more launcher GLOW per unit payload delivered. If you're targeting something in the 1-5klb to orbit range though, it can still be small compared to Falcon 9/Vulcan while also being built a lot more robustly. It won't be as light as a SpaceX style RLV would for the same payload, and it won't be able to do things in the exact same way as a traditional launcher (small RLVs will likely lean a lot more on distributed launch or depots instead of direct missions), but I think it's perfectly feasible. In fact, in many ways I still strongly think that small RLVs are going to get up to high-flight rates long before EELV class ones do.

But that's getting pretty far afield, and into the realm where I'm stating opinions that I can't really prove yet.

~Jon

Offline jongoff

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Re: Reuse business case
« Reply #451 on: 05/11/2016 10:44 pm »
The design and operation choices that SX has made so far clearly have not hurt them. They are producing an expendable LV that has morphed into a plausible reusable first stage. Even in full expendable mode SX has a massive cost advantage on their competition.

Are you saying that their quoted price per launch would be perhaps $57 million (full expendable mode) instead of the current $62 million if SX never even bothered with the effort to land the first stage? If their attitude was F9 is a stable platform and they are not doing any more iterations, then overall it would be cheaper?

These numbers seem like rounding errors compared to the prices of their competitors.

In the big scheme of things, it doesn't seem like it has cost SX much to get to this level of capability. I would be shocked if they have spent more than $50 million on the Grasshopper program, the barges, the labor of the landing effort, etc. They got all of the test landings practically for free by using paying customer launches.

That's not at all what I was trying to say. I was just saying that so far most of the cost savings they've had compared to their competitors has come from design/operations choices, and little so far from reusability, but that I'm optimistic that eventually a larger share of the relative cost savings will start coming from reusability.

~Jon

Offline mkent

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Re: Reuse business case
« Reply #452 on: 05/11/2016 11:40 pm »
That's not at all what I was trying to say. I was just saying that so far most of the cost savings they've had compared to their competitors has come from design/operations choices, and little so far from reusability, but that I'm optimistic that eventually a larger share of the relative cost savings will start coming from reusability.

I agree with Jon's first point whole-heartedly, and I'll agree with his second point on a long enough time scale.  I also think that there is nothing in SpaceX's near-term re-usability scheme that will come close to the cost savings SpaceX would have by just upping their flight rate first into the 12 / year range and then in the 18-20 / year range.

So if I had to rank SpaceX's potential cost advantages over their competition, my ranking would be

1) Design / operational choices
2) High flight-rate
3) High-value component re-use (engines, system components, etc.)
4) Intact stage re-use

This, I think, is the underlying bone of contention (can you feel it?) in this thread between the seasoned veterans at ULA and other places and the SpaceX fans.  SpaceX is trying to jump straight from #1 to #4 when there is much more bang for the buck to be had in steps 2 and 3.

ULA has it worse.  They have to start at #1.  There's no point in even attempting #4 if you don't have a low-cost design or operations.

This, in my opinion, is all that Dr. Sowers was trying to say with his spreadsheet.  There's no need to get too deep into the numbers -- it's meant to be more of a big-picture look at things.

Offline woods170

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Re: Reuse business case
« Reply #453 on: 05/12/2016 06:15 am »
they are going to win a lot of launches after the block buy is over.

Not really.  Spacex is not going to bend to DOD requirements.  They want to keep the F9 generic.
That may be the situation now, but it wasn't during the early cycles of certification. Remember the conclusions of the panel that investigated the dragged-out certification process for F9? It became evident that USAF had forced SpaceX into changing parts of the F9 design. Once this practice was exposed by the panel, the practice was discontinued at the suggestion of the secretary of the air force. From that point forward the certification process became more smooth. Now that USAF can effectively no longer force SpaceX to change the design it is quite easy for SpaceX to say: "Hey general Hyten, we're not gonna bend to you and your boys anymore."
The obvious disadvantage is that Falcon 9 will not be suitable for all USAF and NRO missions. So yeah, they will continue to lose missions to ULA. But then again, in the current situation, that's welcome news for Tory et al..

Offline woods170

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Re: Reuse business case
« Reply #454 on: 05/12/2016 06:21 am »
We already know from an earlier removed post (from a ULA employee) that the reuse business-case model posted by another ULA employee is not to be taken seriously. It holds no merit. Besides, the folks here were very good at taking the model apart and exposing the many flaws in it.
Can we just forget about it? It's pointless to continue discussing a model that is pretty much useless.

Apologies, I wasn't following upthread, I thought I was the first to notice.

This was posted by Dr. Sowers though, and he's more than just an employee - he's a high ranking persona there.

Not cool, not for him, and not for ULA.

EDIT:  Fixed spelling

I agree. It's not cool for Dr. Sowers and ULA to publically post a seriously flawed model and then use it to spread FUD. This was pointed out by the discrediting ULA employee and Lar upthread. Given his senior role within ULA Dr. Sowers really should have known better.

Offline woods170

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Re: Reuse business case
« Reply #455 on: 05/12/2016 06:29 am »

Jim, as of right now, based on what you know, what do you personally think the probability is that SpaceX will fly at least one reused booster at some point? And what do you think the conditional probability of success is, given that they fly one?

An educated guess based on little to no data (but arguably more than most of us have) from you would be interesting.


From what I saw, the aft end needs much more protection.  There were panels that were damaged and opened on the previous booster.  The fires on the current booster may have been internal.   
Careful Jim. You might be giving too much information. Temporary inside insight is good, but you may be walking a red line here.
That aside: it is to be expected that the first succesfully recovered boosters will reveal issues that need addressing. After all, when was the last time someone tried to propulsively recover the first stage of an orbital launcher? SpaceX are the first ones to do so and are therefore the first ones to get a good understanding of the unique problems associated with it.
What I don't doubt for a minute is that SpaceX will ultimately fully understand the causes of the issues and fix them. And given how SpaceX works, the issues will probably be fixed sooner than most competitors expect.

Offline saliva_sweet

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Re: Reuse business case
« Reply #456 on: 05/12/2016 06:29 am »
I believe what they have done up to this point on the design and operation of the vehicle without reuse is a larger impact to the cost of the vehicle than what they will get out of reuse.

But none of this would and probably even could have happened without the promise of reuse and Mars. Mars colonization and rocket reusability have already halved the cost of spaceflight even though no-one has gone to Mars and no rocket has been reused.

How about that for a business case?
« Last Edit: 05/12/2016 06:38 am by saliva_sweet »

Offline Robotbeat

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Re: Reuse business case
« Reply #457 on: 05/12/2016 04:06 pm »

Jim, as of right now, based on what you know, what do you personally think the probability is that SpaceX will fly at least one reused booster at some point? And what do you think the conditional probability of success is, given that they fly one?

An educated guess based on little to no data (but arguably more than most of us have) from you would be interesting.


From what I saw, the aft end needs much more protection.  There were panels that were damaged and opened on the previous booster.  The fires on the current booster may have been internal.   
Careful Jim. You might be giving too much information. Temporary inside insight is good, but you may be walking a red line here....
You can see this on images of the returned stage(s). This really doesn't look like inside info.
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Offline LouScheffer

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Re: Reuse business case
« Reply #458 on: 05/12/2016 04:14 pm »

Would like to point out that all of the structural concerns for recovered boosters as well as most of the retropropulsion plume impingement issues seem to have gone by the wayside.
I'm somewhat surprised they have not taken a used booster, hauled it to Texas, put it in the structural test stand, filled it with an inert fluid, pressurized it, then subjected it to 140% flight loads (or whatever they use for a new booster).  If that test passes, the avionics work, and the engines check out (tested by hot fire) then it would seem they could retire almost all risk.  I would think a full structural test would also a big confidence boost for the first customer of re-use. 

There are several possibilities here.  Maybe they have not gotten to it yet.  Maybe they are sure it would fail from the inspections they have already done, and are waiting for some revision that will do better.    Maybe such a ultimate load test tweaks the booster to the point it can't the re-used, and they are not willing to give up on any recovered boosters yet.  Maybe they are so certain it will pass that it's not worth the trouble to test (though this one seems unlikely to me - SpaceX would surely like to make sure there are no unanticipated problems, and customers would surely like to know SpaceX has checked for this).  Anyway I'm surprised they've not done a full up structural test.

Offline oldAtlas_Eguy

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Re: Reuse business case
« Reply #459 on: 05/12/2016 05:07 pm »
We already know from an earlier removed post (from a ULA employee) that the reuse business-case model posted by another ULA employee is not to be taken seriously. It holds no merit. Besides, the folks here were very good at taking the model apart and exposing the many flaws in it.
Can we just forget about it? It's pointless to continue discussing a model that is pretty much useless.

Apologies, I wasn't following upthread, I thought I was the first to notice.

This was posted by Dr. Sowers though, and he's more than just an employee - he's a high ranking persona there.

Not cool, not for him, and not for ULA.

EDIT:  Fixed spelling

I agree. It's not cool for Dr. Sowers and ULA to publically post a seriously flawed model and then use it to spread FUD. This was pointed out by the discrediting ULA employee and Lar upthread. Given his senior role within ULA Dr. Sowers really should have known better.
With the model presented as being discredited for being applicable to the Reuse Business Case (other than by ULA executives for justifying their own decisions possibly), where does that leave us in the analysis of the reuse business case?

What are the assumptions?
1) That for a given sat weight and delivery orbit, reuse lowers the launch cost.
2) That even if the reuse systems and margins were removed that the $/kg is either equal or less for the reuse case.
3) That flight rate plays an equal part for non-reuse as it does for reuse in generally lower launch costs.

So are these true or false for F9 vs F9R? And are there more assumptions being made?

The problem is we don not know yet. And will not until new prices for launches using reuse is published. We can speculate that SpaceX has answered these and it is in the direction of true. Otherwise they would have stopped and  started new significant vehicle modifications to make them true or to go in in a different direct in the seeking of lower launch costs.

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