Reuse business case

[joek]

I did a ground-up reanalysis of this model, ending up with this spreadsheet (cloneable link).

I might be misunderstanding the spreadsheet, but it seems like you assume:

A) the development cost of SMART to be less than the development cost of a reusable booster. 850 vs 950.
B) The cost of reuse of SMART to be less than the cost of reuse of a reusable booster. 17.6 vs 36.
C) The cost of refurb of SMART to be less than the cost of refurb of a reusable booster. 1.6 vs 3.6.

Assuming I've interpreted that correctly, where do these assumptions come from?

Same question here. One of the issues with the original model was lack of actual costing; or more precisely accounting for different cost models (e.g., ULA vs. SpaceX). Think we beat that to death in the old thread (or maybe it was just me ). Appreciate the addition of actual costing, but need more insight into what those are based on. For example, one issue is that increasing the cost of engines makes SMART look better, but may still result in a non-competitive solution.

[Veedrac]

I did a ground-up reanalysis of this model, ending up with this spreadsheet (cloneable link).

I might be misunderstanding the spreadsheet, but it seems like you assume:

A) the development cost of SMART to be less than the development cost of a reusable booster. 850 vs 950.
B) The cost of reuse of SMART to be less than the cost of reuse of a reusable booster. 17.6 vs 36.
C) The cost of refurb of SMART to be less than the cost of refurb of a reusable booster. 1.6 vs 3.6.

Assuming I've interpreted that correctly, where do these assumptions come from?

A)

$400m for rocket development, based on SpaceX comments for Falcon 9.
$200m for propulsive landing, because it seemed cheaper than a totally novel rocket, but still required significant work eg. with Grasshopper.
$100m for SMART, mostly just to give ULA the benefit of the doubt.
$50m for fairing reuse, because parachutes and nets aren't that expensive.
$350m for miscellaneous other fixed costs not tied to launch or R&D; this is likely conservative for oldspace, but the ULA-like est tab will scale it up by setting Flights total low.

B, C)

These numbers come from the original document, combined with Musk's comments on booster cost. $36m is 60% of SpaceX's marginal costs, using Musk's numbers, and then the refurb and SMART numbers come from Sowers' all-considered percentage costs. The ULA-like est tab was needed to scale fixed costs to match ULA's percentages to the data, and the numbers that gave seemed close enough to reasonable that I ran with them as-is.

I tried to focus on making a better model, rather than critiquing the precise numbers, though I do explore alternative parameters in the various plots. If anyone has different guesses they'd like to see, they can input the numbers themselves easily enough. If you have a solid source for better numbers, I'll happily change the defaults.

[Paul451]

If you have a solid source for better numbers, I'll happily change the defaults.

I don't think anyone has solid numbers. My complaint is just based on what seems like common sense that reusing the Rube Goldberg SMART is surely more costly than reusing an intact booster, certainly not less-than-half the cost. Not just the additional hardware costs, which you've allowed for, but the extra cost of reassembling the old and new parts into a booster.

Likewise, developing a system that can jettison the engine stage, deploy a HIAD-like shield, then a paraglider, then aerial recovery, plus develop the semi-expendable booster that can use such an engine block, would be much more expensive than developing an intact reusable booster.


From your Reddit post:

On the other hand, ULA intends to use spare capacity to ship extra propellant to an orbiting depot.  This justifies the measuring the whole capacity of the rocket

ULA doesn't seem to be pursuing ACES, and hence not looking at depots. I assume this comes from the parent companies, not ULA's internal preference. But is, as is. So I'm not sure the assumption still holds.

[TrevorMonty]

If you have a solid source for better numbers, I'll happily change the defaults.

Likewise, developing a system that can jettison the engine stage, deploy a HIAD-like shield, then a paraglider, then aerial recovery, plus develop the semi-expendable booster that can use such an engine block, would be much more expensive than developing an intact reusable booster.

A reuseable booster would also need new 2nd stage as Centuar is to small and under powered for lower staging speeds. May as will call new RLV New Glenn because that is what they would end up with using BE4 and most likely BE3U as RL10s are to small.

With move to larger diameter booster ULA wouldn't be able to use most of their current 5.4m launch facilities.

SMART might save them $20m launch while RLV could be $40m. But that RLV going cost $1B to develop. Going take lot launches to recover extra development costs.









Sent from my SM-G570Y using Tapatalk

[meekGee]

... my findings support the idea that SMART makes more sense than full booster reuse, up to a fleet average of ~4 flights per booster (SpaceX is at ~2).

A few things make me turn off here.

First is a statement like the above.  How is SpaceX at 2?   Only if you look back to the beginning of the reuse program and average it out.

Which is senseless. You need to look at the current fleet - the old rockets were part of development (and were still profitable so the development cost actually decreased there)

It's the kind of intentional statistics where you decide on a conclusion first, selectively choose your methodology and then say "don't blame me it's just the numbers".

People did that when landing were developed to "prove" low success rate, like saying SpaceX was only, say, X out of Y for landings, ignoring the fact that the good X landings were clearly the last X.

It sounded convincing for about a year but you can only pull that kind of stunt for so long.

Secondly, what do you know about SpaceX cost of reuse?  Is it constant or is it constantly decreasing?  Musk, who should know, said even at N=2, reuse pays back.  Can you say that for SMART, where you still have to build an entirely new rocket every time?

Third - how do you account for F9 experience leading on to Starship?  Starship didn't fall out of the air you know. (I kill me) It's a product of a mindset, and that mindset isn't minimalistic.

[Veedrac]

If you have a solid source for better numbers, I'll happily change the defaults.

I don't think anyone has solid numbers.

A solid source, not solid numbers. Elon Musk has said “recovery & refurb is <10%”, and the ULA document estimated 10% of booster, so I ran with 10% of booster for propulsive landing, and then added a sheet where it was 5%.

https://twitter.com/elonmusk/status/1295883862380294144

Similarly, the sheet said SMART was 10% of engines, which was a touch under half the cost of the booster, so I used that.

I'm going with official guesses over any individual's guesses, without at least strong reason to do otherwise, though again you're free to run the numbers you prefer.

From your Reddit post:

On the other hand, ULA intends to use spare capacity to ship extra propellant to an orbiting depot.  This justifies the measuring the whole capacity of the rocket

ULA doesn't seem to be pursuing ACES, and hence not looking at depots. I assume this comes from the parent companies, not ULA's internal preference. But is, as is. So I'm not sure the assumption still holds.

Even if ACES doesn't happen, Centaur V is meant to be reusable.

It's the kind of intentional statistics where you decide on a conclusion first, selectively choose your methodology and then say "don't blame me it's just the numbers".

If you're going to play this card I'm going to put you on ignore. Read the Reddit comments for some prior commentary I've said on this.

[meekGee]

If you have a solid source for better numbers, I'll happily change the defaults.

I don't think anyone has solid numbers.

A solid source, not solid numbers. Elon Musk has said “recovery &amp; refurb is &lt;10%”, and the ULA document estimated 10% of booster, so I ran with 10% of booster for propulsive landing, and then added a sheet where it was 5%.

https://twitter.com/elonmusk/status/1295883862380294144

Similarly, the sheet said SMART was 10% of engines, which was a touch under half the cost of the booster, so I used that.

I'm going with official guesses over any individual's guesses, without at least strong reason to do otherwise, though again you're free to run the numbers you prefer.

From your Reddit post:

On the other hand, ULA intends to use spare capacity to ship extra propellant to an orbiting depot.  This justifies the measuring the whole capacity of the rocket

ULA doesn't seem to be pursuing ACES, and hence not looking at depots. I assume this comes from the parent companies, not ULA's internal preference. But is, as is. So I'm not sure the assumption still holds.

It's the kind of intentional statistics where you decide on a conclusion first, selectively choose your methodology and then say "don't blame me it's just the numbers".

If you're going to play this card I'm going to put you on ignore. Read the Reddit comments for some prior commentary I've said on this.

Shrug. But your methodology is still selective.

And Musk said &lt;10%, not 10%, and it was 9 months and some 20 landings ago.

SpaceX reuse average is not 2, even if you ignore me.

Given that N today is clearly &gt;10, SMART is proven to be inferior, and by a wide margin

[soyuzu]

Similarly, the sheet said SMART was 10% of engines, which was a touch under half the cost of the booster, so I used that.

No, if reuse a propulsive landed booster, with all parts reusable cost 5-10%, there is zero chance SMART only cost 10%. You need to deal with the HIAD and parachute deployed in recovery operation, mating to tank and testing of plumbing (very likely the stage must be tested as a new booster) that doesn’t happen for propulsive landing.

Even if ACES doesn't happen, Centaur V is meant to be reusable.

Orbital dynamics limited the case of shipping extra propellant to an orbiting depot, not technical feasibility. It’s basically impossible for mission requires various inclination or longitude of Ascending Node. Even for GTO/GEO launches, it means a much narrower  launch/departure window, for both fuel transfer launch and mission that utilize the depot.

And your reply in Reddit about why not expend the booster sounds very doubtful to me.

Thanks. I think the key question here is what's limiting the average flight rate. If it's consistent and predictable wear over time, then final expendable flights are a fairly appealing option. If it's because of randomly distributed failures to land, or damage of a similar sort, there's never a good point to fly expendably, as an aged booster is as good as any other.

Falcon 9 seems more the latter to me. It has flown expendably at times for performance, so there is a small effect here, but it's not like each booster retires with a maxed-out flight.

If the fleet average is lower than the “break even point” you claimed, why care about whether a booster can make 10th flight?

[Veedrac]

Similarly, the sheet said SMART was 10% of engines, which was a touch under half the cost of the booster, so I used that.

No, if reuse a propulsive landed booster, with all parts reusable cost 5-10%, there is zero chance SMART only cost 10%. You need to deal with the HIAD and parachute deployed in recovery operation, mating to tank and testing of plumbing (very likely the stage must be tested as a new booster) that doesn’t happen for propulsive landing.

Well parachutes and connecting a few things together doesn't cost that much. ULA wasn't going to estimate 10% of 18% if HIAD was expected to cost more than that.

Sowers' 10% estimate for propulsive landings was based on reentry wear, which HIAD should largely avoid. As I said on Reddit, “personally that seems way overkill”, but if Musk and ULA both anchor their estimates around 10%, then 10% and 5% seem like fair numbers to use. If it was 5% or less I figure Musk would have used that number instead.

Even if ACES doesn't happen, Centaur V is meant to be reusable.

Orbital dynamics limited the case of shipping extra propellant to an orbiting depot, not technical feasibility. It’s basically impossible for mission requires various inclination or longitude of Ascending Node. Even for GTO/GEO launches, it means a much narrower  launch/departure window, for both fuel transfer launch and mission that utilize the depot.

Centaur V is a bit different to ACES, IIUC. The idea is to have a large number of these upper stages in orbit, each doing unspecified transport work and each lasting up to half a decade in orbit. Since you're sending up a new one on each Vulcan, for in-orbit operations you would just use any spare mass budget as fuel for the Centaur V you just sent up, and only do refuelling proper from ISRU asteroid plants. This still means using all the mass budget in each launch. You'd only do fuel transfers between the stages for larger deep space missions.

I might have gotten a lot of that wrong but I think that's the idea.

And your reply in Reddit about why not expend the booster sounds very doubtful to me.

Thanks. I think the key question here is what's limiting the average flight rate. If it's consistent and predictable wear over time, then final expendable flights are a fairly appealing option. If it's because of randomly distributed failures to land, or damage of a similar sort, there's never a good point to fly expendably, as an aged booster is as good as any other.

Falcon 9 seems more the latter to me. It has flown expendably at times for performance, so there is a small effect here, but it's not like each booster retires with a maxed-out flight.

If the fleet average is lower than the “break even point” you claimed, why care about whether a booster can make 10th flight?

You can think of my and Sowers' graphs as showing the fleet average on the x axis. We're trying to find out under what conditions it's profitable to invest in reusable hardware, using the various techniques, and these less successful earlier boosters were part of that work.

An individual booster making 10 flights is only important inasmuch as it says that if you have many more flights, then you can push towards a 10+ fleet average. But Falcon 9 would need something like 5 times as many flights total for that to happen. While that's pretty reasonable for SpaceX to aim for, as long as you consider Falcon 9 reuse to pay down Starship reuse, that's probably more than ULA can expect to reach any time soon.

[meekGee]

Similarly, the sheet said SMART was 10% of engines, which was a touch under half the cost of the booster, so I used that.

No, if reuse a propulsive landed booster, with all parts reusable cost 5-10%, there is zero chance SMART only cost 10%. You need to deal with the HIAD and parachute deployed in recovery operation, mating to tank and testing of plumbing (very likely the stage must be tested as a new booster) that doesn’t happen for propulsive landing.

Well parachutes and connecting a few things together doesn't cost that much. ULA wasn't going to estimate 10% of 18% if HIAD was expected to cost more than that.

Sowers' 10% estimate for propulsive landings was based on reentry wear, which HIAD should largely avoid. As I said on Reddit, “personally that seems way overkill”, but if Musk and ULA both anchor their estimates around 10%, then 10% and 5% seem like fair numbers to use. If it was 5% or less I figure Musk would have used that number instead.

Even if ACES doesn't happen, Centaur V is meant to be reusable.

Orbital dynamics limited the case of shipping extra propellant to an orbiting depot, not technical feasibility. It’s basically impossible for mission requires various inclination or longitude of Ascending Node. Even for GTO/GEO launches, it means a much narrower  launch/departure window, for both fuel transfer launch and mission that utilize the depot.

Centaur V is a bit different to ACES, IIUC. The idea is to have a large number of these upper stages in orbit, each doing unspecified transport work and each lasting up to half a decade in orbit. Since you're sending up a new one on each Vulcan, for in-orbit operations you would just use any spare mass budget as fuel for the Centaur V you just sent up, and only do refuelling proper from ISRU asteroid plants. This still means using all the mass budget in each launch. You'd only do fuel transfers between the stages for larger deep space missions.

I might have gotten a lot of that wrong but I think that's the idea.

And your reply in Reddit about why not expend the booster sounds very doubtful to me.

Thanks. I think the key question here is what's limiting the average flight rate. If it's consistent and predictable wear over time, then final expendable flights are a fairly appealing option. If it's because of randomly distributed failures to land, or damage of a similar sort, there's never a good point to fly expendably, as an aged booster is as good as any other.

Falcon 9 seems more the latter to me. It has flown expendably at times for performance, so there is a small effect here, but it's not like each booster retires with a maxed-out flight.

If the fleet average is lower than the “break even point” you claimed, why care about whether a booster can make 10th flight?

You can think of my and Sowers' graphs as showing the fleet average on the x axis. We're trying to find out under what conditions it's profitable to invest in reusable hardware, using the various techniques, and these less successful earlier boosters were part of that work.

An individual booster making 10 flights is only important inasmuch as it says that if you have many more flights, then you can push towards a 10+ fleet average. But Falcon 9 would need something like 5 times as many flights total for that to happen. While that's pretty reasonable for SpaceX to aim for, as long as you consider Falcon 9 reuse to pay down Starship reuse, that's probably more than ULA can expect to reach any time soon.

If the life leaders are at 10 flights, then N more or less equals 10 for the purpose of planning or evaluating options.

Not considering this is simply burying your head in the sand, which is sadly exactly what ULA has done.

"Nothing to worry about, the fire hasn't reached our floor yet, in fact the average floor on fire is only 4”

Except now you've just seen a 10 story building burn down, and you're still trying to refine that argument.

[Veedrac]

If the life leaders are at 10 flights, then N more or less equals 10 for the purpose of planning or evaluating options.

No, they can only do this if they nail the landing first time and every time, and don't have to learn their way past the same hurdles SpaceX did. Realistically ULA would still take a bunch of flights to figure out reuse, and then have to amortize those out to get a high fleet average. And ULA is in the tough position where they don't have nearly as many flights as SpaceX now does, so it'll take them much longer to do it.

[ZachF]

Oooh, thread necromancy!

TBH, even if booster reuse was somehow much more marginal than it appears to be in reality, it's worth pursuing because it's on the development tree to full reuse... and full reuse is where the real savings come.

[ehb]

Oooh, thread necromancy!

TBH, even if booster reuse was somehow much more marginal than it appears to be in reality, it's worth pursuing because it's on the development tree to full reuse... and full reuse is where the real savings come.

I was thinking along the same lines.

These costing arguments seem short-sighted to me.
Where does the knowledge (IP) gained by trying reuse factor in?
While ULA creates a spreadsheet about the value of reuse (to convince stakeholders?),
SpaceX is plowing IP gained in F9 reuse into SH/SS promising cheap rapid reuse.

[ZachF]

Oooh, thread necromancy!

TBH, even if booster reuse was somehow much more marginal than it appears to be in reality, it's worth pursuing because it's on the development tree to full reuse... and full reuse is where the real savings come.

I was thinking along the same lines.

These costing arguments seem short-sighted to me.
Where does the knowledge (IP) gained by trying reuse factor in?
While ULA creates a spreadsheet about the value of reuse (to convince stakeholders?),
SpaceX is plowing IP gained in F9 reuse into SH/SS promising cheap rapid reuse.

The upper bound of booster reuse savings is probably on the order of 60% (~70% of the payload at ~30% the cost), and the lower bound is probably zero, with reality in between. I'd estimate about 40%ish.

Ultimately though, booster reuse is still throwing away millions in equipment every launch. Full reuse is how you get orders of magnitude cost drops.

[RoadWithoutEnd]

No, they can only do this if they nail the landing first time and every time, and don't have to learn their way past the same hurdles SpaceX did. Realistically ULA would still take a bunch of flights to figure out reuse, and then have to amortize those out to get a high fleet average. And ULA is in the tough position where they don't have nearly as many flights as SpaceX now does, so it'll take them much longer to do it.

ULA dug a whole for itself over a decade deep when it formed in the first place to cement Boeing and Lockheed's expendables as the "once and forever" US government rocket solution.  But even when the evidence was clear that this was a mistake, they made no effort to climb out.  Institutions have made clear that ULA would be kept alive no matter what as a backup, regardless of how obsolete their tech became, or how expensive their launches are.

ULA is now more a ward of the state rather than a launch asset: A vassal institution with protected jobs and contracts awarded by default, but increasingly irrelevant to spaceflight.  They have no practical path to reusability, and have apparently opted for a slow decline that will end in exiting the launch market (which was never a majority of either Boeing or Lockheed's business).

[soyuzu]

Well parachutes and connecting a few things together doesn't cost that much. ULA wasn't going to estimate 10% of 18% if HIAD was expected to cost more than that.

Sowers' 10% estimate for propulsive landings was based on reentry wear, which HIAD should largely avoid. As I said on Reddit, “personally that seems way overkill”, but if Musk and ULA both anchor their estimates around 10%, then 10% and 5% seem like fair numbers to use. If it was 5% or less I figure Musk would have used that number instead..

How has reentry wear do with refurbishment costs? You neither rebuild the Octaweb nor reapply heat shields for reentry wear. Simply retire it when the wear is deemed too much. Reentry wear should not be recounted for both stage life and refurbishment cost.

And the thing you believe will not cost that much is exactly why rocket cost significant more than engine+aluminum barrels. If you regard them as minor work, Falcon 9 would need zero refurbishment.

Centaur V is a bit different to ACES, IIUC. The idea is to have a large number of these upper stages in orbit, each doing unspecified transport work and each lasting up to half a decade in orbit. Since you're sending up a new one on each Vulcan, for in-orbit operations you would just use any spare mass budget as fuel for the Centaur V you just sent up, and only do refuelling proper from ISRU asteroid plants.

No difference, even fuel is not transferred, payload still need to dock with stage in orbit. Not to mention F9 itself will be obsolete by Starship long before ULA do ISRU from NEOs.

An individual booster making 10 flights is only important inasmuch as it says that if you have many more flights, then you can push towards a 10+ fleet average. But Falcon 9 would need something like 5 times as many flights total for that to happen.

This is exactly why I think you not counting expended on last flight doubtful. A booster is immediately break even after it is intentionally expended, so they should not be counted into the fleet average when you are calculating break even point. There are 11 not intentionally expended Block 5 core for 59 recoverable mission, so a fleet average already larger than 5, even if you count all flight after B1019, the average is already larger than 3.

[soyuzu]

Oooh, thread necromancy!

TBH, even if booster reuse was somehow much more marginal than it appears to be in reality, it's worth pursuing because it's on the development tree to full reuse... and full reuse is where the real savings come.

I was thinking along the same lines.

These costing arguments seem short-sighted to me.
Where does the knowledge (IP) gained by trying reuse factor in?
While ULA creates a spreadsheet about the value of reuse (to convince stakeholders?),
SpaceX is plowing IP gained in F9 reuse into SH/SS promising cheap rapid reuse.

Not to mention almost no rockets before Falcon 9 were expected to recover the development cost through commercial launch, even for rocket designed for commercial markets like Ariane.

[meekGee]

If the life leaders are at 10 flights, then N more or less equals 10 for the purpose of planning or evaluating options.

No, they can only do this if they nail the landing first time and every time, and don't have to learn their way past the same hurdles SpaceX did. Realistically ULA would still take a bunch of flights to figure out reuse, and then have to amortize those out to get a high fleet average. And ULA is in the tough position where they don't have nearly as many flights as SpaceX now does, so it'll take them much longer to do it.

Yup but he who dares wins.

And after the first guy dares, it takes a lot less daring to do it, because various unknowns are now known.   N being the biggest one but not thr only one.

The only way to make such a calculation is to use either a prediction or an approximation of the steady state values.  Who cares if the first 10 rockets had N=2?   The 1000 before them had N=1!

Right now a rocket designer knows that N is at least 10, and (another doubt removed by SpaceX) customers will work with you and won't run for the hills if you practice reusability on commercial launches.

Those were huge unknowns.

..and when I said you're using N=2 "on purpose", it wasn't like you're trying to lie..  but you're introducing your bias into your statistics methodology - even subconsciously.  I'm not trying to damn you to statistician's hell,, I'm trying to show you and hope you'll correct...

Peace.

[Veedrac]

Oooh, thread necromancy!

TBH, even if booster reuse was somehow much more marginal than it appears to be in reality, it's worth pursuing because it's on the development tree to full reuse... and full reuse is where the real savings come.

Note that these charts are calculating amortized marginal cost. This is important because it means the immediate marginal cost to SpaceX right now can be a lot lower, which gives them a lot of power to decide optimal pricing. If SpaceX expected that the market would grow by a large enough factor if they priced launch at $30m, they could do so, and the competition would suffer dearly for it, at least to the extent that they still have market share to lose.

So if you're looking at current launch cost estimates and thinking they seem a bit lower than my or Sowers' estimates, just note that these are different measures and they might not actually disagree.

These costing arguments seem short-sighted to me.
Where does the knowledge (IP) gained by trying reuse factor in?

I agree to the extent that if SpaceX is doing full reuse, you better copy them and pray the market appears to support it. Because if you don't, you lose either way.

How has reentry wear do with refurbishment costs? You neither rebuild the Octaweb nor reapply heat shields for reentry wear. Simply retire it when the wear is deemed too much. Reentry wear should not be recounted for both stage life and refurbishment cost.

Inspections, repair, engine swaps, cleaning, etc. Note that this only represents a portion of the 10% cost, and note again that I also think 10% seems pessimistic.

No difference, even fuel is not transferred, payload still need to dock with stage in orbit. Not to mention F9 itself will be obsolete by Starship long before ULA do ISRU from NEOs.

I don't understand what point you're making here. Each useful orbit would have its Centaur V, so there'd typically already be one close by regardless of inclination.

This is exactly why I think you not counting expended on last flight doubtful.

I agree but I do account for expended payload on the last flight. See the Reddit thread for details.

[butters]

The economics of this industry is governed by fixed costs over launch rate. The reusability method that enables the highest launch rates will have a considerable advantage that can even overcome higher cost structures -- especially in an era of LEO constellations and hopefully orbital propellant.

The business case for reusable engine pod concept like SMART is really about the efficiency of the the turnaround flow. How often would they be able to launch each engine pod? What's the sustainable production rate for the booster tanks? How well does this system scale to 30, 40, 50 missions per year?

If one system can operate several times as frequently as another system of similar capacity, that's going to be the more economical of the two systems. Period.

I'm excited for the Kuiper launch campaign (whenever it eventually occurs) as an opportunity for ULA to show what kind of cadence they can achieve with the extremely mature Atlas V. The turnaround record for LC-41 is 42 days. ULA has suggested a 30-day turnaround capability. This is disconcerting in the context of contemporary developments in the industry, but it would be nice to see ULA reel off a string of launches at something close to a monthly rate.

I agree that with an RL-10 powered upper stage, a reusable booster really isn't an option. Maybe SMART is a good way to maximize Vulcan flight rate which might otherwise be limited by BE-4 production rate (which is a mystery). Vulcan tanks are not cheap, but Boeing decided way back when to build the production capacity for 60 Delta IV cores per year at Decatur, so it's not completely unreasonable.

SMART could make Vulcan significantly less uncompetitive with Falcon and either a bridge to New Glenn or a complement to New Glenn. A lot depends on how late New Glenn becomes. The farther away New Glenn really is, the more it makes sense for ULA to invest in SMART. If New Glenn is not going to be a high-rate launch system, then ULA should invest in SMART.

We could end up having a real-life demonstration of this thread's premise: reusable engine pod + low-thrust hydrolox upper vs. reusable booster stage + high-thrust hydrolox upper. Both based on the same booster engine. Which will be better? Well, if they both launch once a month, they'll probably cost about the same.