SLS General Discussion Thread 8

[oldAtlas_Eguy]

I genuinely believe that the Chinese beating Artemis on the Moon could be a very good thing for NASA and prompt a rapid refocus on Mars. In this situation, I dare to hope that NASA's budget would be increased significantly. If the people at Michoud got the necessary funding, I think they would be perfectly capable of producing 1 or 2 SLSs per year. Sometimes there's nothing better than a good old kick in the ass, in the same way Sputnik and Gagarin led the US to Apollo 11.

With a nuke-thermal transit stage, Mars DRM 5.0 needs at least seven (7) launches of a 130t lifter within twenty-six (26) months (a little more than two years).  At the other end of the spectrum, with chemical propulsion and aerocapture, Mars DRM 5.0 needs at least eighteen (18) launches of a 70t lifter within twenty-six (26) months (a little more than two years).  There are options in between, but these bound the space.

Even at a rate of two (2) per year, SLS production can’t meet these figures by a factor of two (2x) to nine (9x).  And even if production was that high, given STS history and what we’re seeing on Artemis I, the likelihood that SLS can reliably pull off that many launches within that window is dubious at best.

And that’s for one Mars expedition.  If you want keep going at each opportunity, you have to quadruple or so these numbers over a decade.  That’s just not within the realm of a craft- or cottage-industry launch technology base like STS/SLS.  I’m not saying SpaceX has the answer, but if you’re serious about Mars, you need something approaching industrial scale production levels like the Falcon family or Starliner/Superheavy.

The mass of a single Mars expedition — 849t for nuke-thermal or 1252t for chemical/aerocapture according to Mars DRM 5.0 — exceeds or is in the ballpark of all the payload mass put into orbit by the entire world annually (depending on what year you’re looking at).  You literally have to create or find a launch capability equal to the rest of the world combined to send humans to Mars.  SLS falls far, far short of that.

Maybe someone should point out to the administrator that we went from the Wright brothers first flight to the moon in about six decades, but that the SLS Mars DRM designs are still the same as six decades ago (see e.g. the EMPIRE thread).

The reason Super Heavy lifters are envisioned for the Mars DRMs is that in order to do the launch of that much tonnage in a year. NASA could not figure out any other way to launch fast enough except a handful (5+) of the 100t+ SHLVs. NOTE that F9 at 60 launches this year will have launched an equivalent of 900t = (15t reusable launch configuration)*60. To get 1300t it would be 90 launches which is not inconceivable a launch rate increase in 1 year of 50%. This year is a 100% increase in launch rate from last year (2021). Also the cost of 90 launches of F9 is $60M each (actually less) *90 = $5.4B. Only ~2.5X SLS cost of $2.1B but is equivalent in tonnage to 19 SLS launches which would cost even if SLS could get to $1B (50% of current) of $19B. Even in using the possible SLS 2 it would be 10 launches at $10B. One launch method exists now the other would be available sometime in 2030.

That is no longer the case and NASA should stop planning missions in that direction.

[Zed_Noir]

<snip>
The mass of a single Mars expedition — 849t for nuke-thermal or 1252t for chemical/aerocapture according to Mars DRM 5.0 — exceeds or is in the ballpark of all the payload mass put into orbit by the entire world annually (depending on what year you’re looking at).  You literally have to create or find a launch capability equal to the rest of the world combined to send humans to Mars.  SLS falls far, far short of that.

As a fun exercise. 

So it is about 1250 tonnes of payloads from your post's estimate for the Mars DRM 5.0 with chemical propulsion and aerocapture or roughly 84 Falcon 9 launches with down range recovery. A conservative launch cadence of 2 Falcon 9 every week from 2 new pads with 8 dedicated Falcon 9 cores supported by at least 4 dedicated recovery barges will take only about 42 weeks to loft 1250 tonnes to LEO.

Amusingly the cost a single SLS Block 1 flight with Orion is about $4.1B according to the GAO. Which is roughly what 84 Falcon 9 launches will cost for $4.6B at $55M per launch.

Of course you need to add the cost of building 2 launch pads and 2 vehicle integration buildings plus acquiring 4 recovery barges and maritime recovery operations. Maybe another $1.5B. Need the new facilities and hardware to not tied up the old facilities.
 
So the archaic Mars DRM 5.0 could be assembled in LEO in about 11 months and the cost of less than 2 SLS Block 1 launches with a fleet of 8 dedicated Falcon 9s.

The path to Mars with any SLS involvement seems to be too costly.

[Darn, got ninja'd by @oldAtlasEguy]

[oldAtlas_Eguy]

F9 is not the only one. Vulcan supposedly has the planned launch rate maximum off the existing LC41 pad of 20-24 /yr. At 33t each and $150M cost it would take a total of ~2 years (which is in the required 26 month period) of 40 launches at total cost of $6B. Then eventually there is NG the wild card in this group. All without even considering the disruptive Starship.

Unlike at the 2004 point where the options for smaller launchers required some significant amounts of fixed additional infrastructure. The current small (15-35t) actually heavy launchers does not require much more than $250M in fixed infrastructure at most. Some could get away with practically 0. But all of that is likely to be covered by commercial firms and recovered over the years of operations profits in the amounts of $1B/yr and likely could be more.

OK now SLS in order to increase its build rates to 4 a year would need several $Bs in new tooling to replicate the existing. Although it may eventually be able to launch at the same pad it would need a second identical ML which costs a few $B all by itself and requires 5-7 years of construction time. Maybe hopefully they could do it for less cost and faster.

[Coastal Ron]

Supporting programs for decades on end is well-trodden territory for defense contractors...

That said, for a program like SLS that appears to have a low deliverable count, Boeing et. al. may acquire all necessary parts right from the get-go. Unlike say, missiles, where hundreds or thousands may be ordered over the life of the program, storing electronics for 10-ish SLS vehicles is likely to be comparatively cheap. Having a single lot codes for many of them probably helps enough with traceability, data group purchases, etc. to make it worthwhile from day 1.

Of all the problems future-SLS might face, this one is pretty straightforward to solve.

I'm not so sure that Boeing has the economic incentive to go beyond supporting their current contract of 10ea SLS Core.

Boeing would have the economic incentive to do a "lifetime buy" for the current tranche of contracts, since they are currently working under a Cost Plus contract, so they get profit from buying parts early and storing them.

But I can't see Boeing spending their own money to buy parts for units that are not under contract.

[1]

...
That said, for a program like SLS that appears to have a low deliverable count, Boeing et. al. may acquire all necessary parts right from the get-go. Unlike say, missiles, where hundreds or thousands may be ordered over the life of the program, storing electronics for 10-ish SLS vehicles is likely to be comparatively cheap. Having a single lot codes for many of them probably helps enough with traceability, data group purchases, etc. to make it worthwhile from day 1.
...

I'm a bit concerned about Orion. The "we have to reuse electronics from A1 on A2 despite adding months to the launch rate" thing feels very odd. They didn't buy enough components?

I can think of a few reasons for this, though none of them are really 'good'. If I had to guess, knowing nothing more about the program than the next person on this site, I would guess that a design revision or something is in works, and the design simply isn't stable enough to know what's going to be needed a few years down the road. I've seen design changes come frustratingly late in a program life cycle (post CDR) and it's never pleasant. Lifetime buy is generally done from a standpoint of design stability, otherwise there's little point.

Supporting programs for decades on end is well-trodden territory for defense contractors...

That said, for a program like SLS that appears to have a low deliverable count, Boeing et. al. may acquire all necessary parts right from the get-go. Unlike say, missiles, where hundreds or thousands may be ordered over the life of the program, storing electronics for 10-ish SLS vehicles is likely to be comparatively cheap. Having a single lot codes for many of them probably helps enough with traceability, data group purchases, etc. to make it worthwhile from day 1.

Of all the problems future-SLS might face, this one is pretty straightforward to solve.

I'm not so sure that Boeing has the economic incentive to go beyond supporting their current contract of 10ea SLS Core.

Boeing would have the economic incentive to do a "lifetime buy" for the current tranche of contracts, since they are currently working under a Cost Plus contract, so they get profit from buying parts early and storing them.

But I can't see Boeing spending their own money to buy parts for units that are not under contract.

Oh, I agree. Mentioned contractual obligations in my earlier post. Perhaps the earlier comments were referring to additional missions beyond the current contract? If so, I probably misread them. In that case, one might get lucky by having additional parts on hand that were procured as engineering samples or spares or whatnot, but about the best you could hope for is to buy yourself a launch or two's worth of time while a redesign is in work.

[oldAtlas_Eguy]

Of the next SLS/Orion combined into 1 contract either on contract or will be soon of the Artemis V through IX and then an option for Artemis X to XIV. But because the option has not been bought yet and would need a contract mod to exercise it. So the long lead parts for those may not be allowed yet. If that is the case that there is not a line item on the contract for long lead critical parts for those missions X-XIV as well. Then their purchase via a contract mod somewhere around Artemis III, IV or V is the likely time frame. That would be sometime from 2026 to 2029.

I don't think that for V through IX parts may be not to difficult to get to finish those. Unless damage to Avionics boxes or parts fail and have to be replaced or complete boards needing more parts than what was purchased as long lead buy. I can see a purchase for the new box even if the parts exists to possibly cost as much as all 5 of the previous block buy to replace a a single damaged or failed box. The subcontractor who built the previous 5 may no longer be in business 5+ years from now.

[Timber Micka]

I genuinely believe that the Chinese beating Artemis on the Moon could be a very good thing for NASA and prompt a rapid refocus on Mars. In this situation, I dare to hope that NASA's budget would be increased significantly. If the people at Michoud got the necessary funding, I think they would be perfectly capable of producing 1 or 2 SLSs per year. Sometimes there's nothing better than a good old kick in the ass, in the same way Sputnik and Gagarin led the US to Apollo 11.

With a nuke-thermal transit stage, Mars DRM 5.0 needs at least seven (7) launches of a 130t lifter within twenty-six (26) months (a little more than two years).  At the other end of the spectrum, with chemical propulsion and aerocapture, Mars DRM 5.0 needs at least eighteen (18) launches of a 70t lifter within twenty-six (26) months (a little more than two years).  There are options in between, but these bound the space.

Even at a rate of two (2) per year, SLS production can’t meet these figures by a factor of two (2x) to nine (9x).  And even if production was that high, given STS history and what we’re seeing on Artemis I, the likelihood that SLS can reliably pull off that many launches within that window is dubious at best.

And that’s for one Mars expedition.  If you want keep going at each opportunity, you have to quadruple or so these numbers over a decade.  That’s just not within the realm of a craft- or cottage-industry launch technology base like STS/SLS.  I’m not saying SpaceX has the answer, but if you’re serious about Mars, you need something approaching industrial scale production levels like the Falcon family or Starliner/Superheavy.

The mass of a single Mars expedition — 849t for nuke-thermal or 1252t for chemical/aerocapture according to Mars DRM 5.0 — exceeds or is in the ballpark of all the payload mass put into orbit by the entire world annually (depending on what year you’re looking at).  You literally have to create or find a launch capability equal to the rest of the world combined to send humans to Mars.  SLS falls far, far short of that.

Thanks for the reminder, but yeah DRM 5 is a ridiculous and outdated plan.
If for whatever reason NASA wants to launch a Mars expedition on SLS, it's more likely to use Solar Electric Propulsion (2017's Deep Space Transport MTV concept comes to mind).

NASA's 2017 DST presentation says that the SEP MTV is "launched on one SLS 1B cargo vehicle - resupply and minimal outfitting to be performed in cislunar space" (I read that as "launch on SLS, refueling and outfitting by commercial LVs")
1 DST = 3 Mars expeditions
That sounds fair to me.

https://nvite.jsc.nasa.gov/presentations/b2/D1_Mars_Connolly.pdf

[su27k]

https://twitter.com/jeff_foust/status/1582747555640639488

Updated this story after learning from NASA that the EPOC contract (the one that would go to the Boeing-NG joint venture) would only cover Artemis missions. The pre-solicitation statement had mentioned an option for additional non-Artemis SLS launches that’s no longer part of it.

https://spacenews.com/nasa-outlines-case-for-making-sole-source-sls-award-to-boeing-northrop-joint-venture/

NASA added in the justification statement that it will look for “alternative solutions or new sources” before exercising any options on the EPOC contract, which as currently proposed would cover the Artemis 5 through 9 missions with options for Artemis 10 through 14. NASA, in the pre-solicitation statement in July, said that the contract would also include an option for up to 10 non-Artemis SLS missions, but NASA spokesperson Rachel Kraft said Oct. 19 that the agency had “refined our planning” and would limit EPOC to the 10 Artemis missions listed in the justification statement.

Sounds like this killed the idea of using SLS for science missions, I assume it also means no commercial missions for SLS. Both are expected, but good to see them confirmed given some SLS supporters keep quoting so called "insider information" to claim SLS has other uses besides Orion.

[oldAtlas_Eguy]

Maybe it was dropped off is that the IX mission may be sometime after 2034. That maybe to far out already to project costs. Currently even next year is to far out to project costs accurately.

As far as the FAR to go past a 5 year length it requires the approval of the NASA chief. To go past the 10 year length requires the written approval about exceptional circumstance by the Sec of the Interior. That second one may be determined as a bridge to far. Forgive the PUN. Also that would likely mean that contract award may be moving more toward the right as well to accommodate the 10 year period that only the NASA boss has to sign for. Also Note that a 10 year period of time is plenty of duration to come up with something new to replace it like a commercial provider that offers the capability as a common service.

[lrk]

Parts are rather interesting in that the more common use the part is the more likely it may still be in production even 20 to 30 years. TTL compatible NAND quad chips 14 pin 5V are still available and those were introduced in early 1970's. They have been in production or a facsimile of them for >50 years. Low quantity chips for a radiation tolerant chip set that were in production several years before 2012 when SLS and Orion got going in ernest are the likely ones used. Those may be available but extremely expensive, 10s of thousands of dollars each making the price of the parts for a single box could cost >$1M.

Use of exotic rad-hardened parts is a completely different story, as you say, and of course it affects Orion. Maybe SLS not so much as it has far less exposure time to radiation.

That would just make too much sense. 

IIRC, the Orion launch abort motor controller was using a giant rad-hardened FPGA to emulate a microprocessor.  Despite only   spending a few minutes outside of the atmosphere... so I wouldn't be too optimistic about the rad hardness requirements being relaxed for the rest of SLS. 

[VSECOTSPE]

Thanks for the reminder, but yeah DRM 5 is a ridiculous and outdated plan.
If for whatever reason NASA wants to launch a Mars expedition on SLS, it's more likely to use Solar Electric Propulsion (2017's Deep Space Transport MTV concept comes to mind).

So does JIMO, which went nowhere.  Large-scale electric propulsion is not a panacea.  The scale needed for human space flight is orders of magnitude larger than any electric propulsion to date (or even planned for Gateway), which raises all sorts of issues from propellant supply to spacecraft charging effects.  Large-scale electric propulsion should be in the tradespace and the technology should be pushed.  But it’s far from a certain bet at this time.

(I read that as "launch on SLS, refueling and outfitting by commercial LVs")

Even a mostly electric stack for humans-to-Mars needs a handful/half-dozen HLV launches.  The current HEOMD-007 “plan” requires at least four launches (dual NEP stages, a chemical stage, and the TH), along with an unspecified number of “commercial tankers” and a checkout crew rotation before leaving for lunar orbit and then Mars.   If the government-run HLV can only support one or two of those launches within the assembly window and the rest will have to be addressed by commercial HLVs, then we should stop wasting taxpayer and program resources on the oddball, low-cadence, government-run HLV and use the nation’s commercial HLV fleet for all the launches instead.

[VSECOTSPE]

Sounds like this killed the idea of using SLS for science missions, I assume it also means no commercial missions for SLS.

Surprise, surprise...

[whitelancer64]

...
That said, for a program like SLS that appears to have a low deliverable count, Boeing et. al. may acquire all necessary parts right from the get-go. Unlike say, missiles, where hundreds or thousands may be ordered over the life of the program, storing electronics for 10-ish SLS vehicles is likely to be comparatively cheap. Having a single lot codes for many of them probably helps enough with traceability, data group purchases, etc. to make it worthwhile from day 1.
...

I'm a bit concerned about Orion. The "we have to reuse electronics from A1 on A2 despite adding months to the launch rate" thing feels very odd. They didn't buy enough components?

I can think of a few reasons for this, though none of them are really 'good'. If I had to guess, knowing nothing more about the program than the next person on this site, I would guess that a design revision or something is in works, and the design simply isn't stable enough to know what's going to be needed a few years down the road. I've seen design changes come frustratingly late in a program life cycle (post CDR) and it's never pleasant. Lifetime buy is generally done from a standpoint of design stability, otherwise there's little point.

It's a demonstration of reuse, and that is the only reason they are doing it. Some of the avionics and etc. for Artemis 3 have been ordered and are already being assembled.

They want to do it as a precursor to full reuse of the Orion for Artemis 3 on Artemis 6. Some early experience with subsystem reuse buys down risk for future full capsule reuse.

[leovinus]

https://twitter.com/jeff_foust/status/1582747555640639488

Updated this story after learning from NASA that the EPOC contract (the one that would go to the Boeing-NG joint venture) would only cover Artemis missions. The pre-solicitation statement had mentioned an option for additional non-Artemis SLS launches that’s no longer part of it.

https://spacenews.com/nasa-outlines-case-for-making-sole-source-sls-award-to-boeing-northrop-joint-venture/

Thank you for bringing the story to our attention. I took the opportunity to contact The White House directly and voice my displeasure at a sole-source contract, throwing good money after a bad cause. I simply requested more space innovation and multiple sources instead. 

As a taxpayer, I am willing to pay for a rocket out of the Jetsons but not for a rehash of a 60 year old rocket.  Every Jane and Joe Sixpack notice the difference in experience between an iPhone and a flip phone, or an electric Tesla vs a Chevy. NASA can do innovation in space again but they need direction and budget.

[yg1968]

https://twitter.com/jeff_foust/status/1582747555640639488

Updated this story after learning from NASA that the EPOC contract (the one that would go to the Boeing-NG joint venture) would only cover Artemis missions. The pre-solicitation statement had mentioned an option for additional non-Artemis SLS launches that’s no longer part of it.

https://spacenews.com/nasa-outlines-case-for-making-sole-source-sls-award-to-boeing-northrop-joint-venture/

NASA added in the justification statement that it will look for “alternative solutions or new sources” before exercising any options on the EPOC contract, which as currently proposed would cover the Artemis 5 through 9 missions with options for Artemis 10 through 14. NASA, in the pre-solicitation statement in July, said that the contract would also include an option for up to 10 non-Artemis SLS missions, but NASA spokesperson Rachel Kraft said Oct. 19 that the agency had “refined our planning” and would limit EPOC to the 10 Artemis missions listed in the justification statement.

Sounds like this killed the idea of using SLS for science missions, I assume it also means no commercial missions for SLS. Both are expected, but good to see them confirmed given some SLS supporters keep quoting so called "insider information" to claim SLS has other uses besides Orion.

I sort of wonder if a sole-source contract for non-Artemis missions could be justified. The justification becomes a lot harder for science missions.

In terms of commercial SLS missions, NASA wouldn't be involved, so this sole-source document wouldn't cover those. But I doubt that commercial SLS missions will ever happen.

[woods170]

Updated this story after learning from NASA that the EPOC contract (the one that would go to the Boeing-NG joint venture) would only cover Artemis missions. The pre-solicitation statement had mentioned an option for additional non-Artemis SLS launches that’s no longer part of it.

https://spacenews.com/nasa-outlines-case-for-making-sole-source-sls-award-to-boeing-northrop-joint-venture/

NASA added in the justification statement that it will look for “alternative solutions or new sources” before exercising any options on the EPOC contract, which as currently proposed would cover the Artemis 5 through 9 missions with options for Artemis 10 through 14. NASA, in the pre-solicitation statement in July, said that the contract would also include an option for up to 10 non-Artemis SLS missions, but NASA spokesperson Rachel Kraft said Oct. 19 that the agency had “refined our planning” and would limit EPOC to the 10 Artemis missions listed in the justification statement.

Sounds like this killed the idea of using SLS for science missions, I assume it also means no commercial missions for SLS. Both are expected, but good to see them confirmed given some SLS supporters keep quoting so called "insider information" to claim SLS has other uses besides Orion.

I sort of wonder if a sole-source contract for non-Artemis missions could be justified. The justification becomes a lot harder for science missions.

Emphasis mine.

It is quite simple. Right now NASA can't order SLS vehicles for non-existing NASA non-Artemis missions.

There are several missions in the recent decadal survey mentioning SLS as "possible" launch vehicles. But most of those missions will never become reality. For those that do the launch vehicle is selected at a later time (several years from now in fact). There is no guarantee that at selection time the SLS will be the optimal choice.

Ordering a few extra SLS vehicles for non-Artemis missions therefore runs a very serious risk of those vehicles (at a price tag of $2B each) suffering the ultimate fate of gathering dust in a warehouse indefinitely. That is, until they are retired to museums or scrapped. Heck, it is even possible that several of the currently ordered SLS Block 1B vehicles will suffer the same fate as the last 3 Saturn V vehicles. I don't believe for a minute that the Artemis program will still be using Orion and SLS for crew transport beyond 2030.

[libra]

- Saturn V HLV was given a science mission - Voyager-Mars. It was killed as insanely expensive.
- Back in 2008 was a National Academies report examining Ares V -allowed science missions. Lots of them, but insanely expensives.
- Back in 2019 SLS tried to snatch an Europa mission. Nice tried, but as soon as Congressman Culbertson retired, the proposal died.
So not really surprised SLS science missions have gone nowhere...

[clongton]

- Saturn V HLV was given a science mission - Voyager-Mars. It was killed as insanely expensive.
- Back in 2008 was a National Academies report examining Ares V -allowed science missions. Lots of them, but insanely expensive.
- Back in 2019 SLS tried to snatch an Europa mission. Nice tried, but as soon as Congressman Culbertson retired, the proposal died.
So not really surprised SLS science missions have gone nowhere...

The ultra high expense of using SLS as a launch vehicle for a science mission far outweighs any possible advantage the SLS might supply by an order of magnitude. There are other launch vehicles that can do the same job far, FAR less expensively. SLS is stupid expensive. It will never fly a science mission - ever.

[Zed_Noir]

- Saturn V HLV was given a science mission - Voyager-Mars. It was killed as insanely expensive.
- Back in 2008 was a National Academies report examining Ares V -allowed science missions. Lots of them, but insanely expensive.
- Back in 2019 SLS tried to snatch an Europa mission. Nice tried, but as soon as Congressman Culbertson retired, the proposal died.
So not really surprised SLS science missions have gone nowhere...

The ultra high expense of using SLS as a launch vehicle for a science mission far outweighs any possible advantage the SLS might supply by an order of magnitude. There are other launch vehicles that can do the same job far, FAR less expensively. SLS is stupid expensive. It will never fly a science mission - ever.

The same can be said for any other missions. The SLS is simply too expensive with a low launch cadence.

[mn]

- Saturn V HLV was given a science mission - Voyager-Mars. It was killed as insanely expensive.
- Back in 2008 was a National Academies report examining Ares V -allowed science missions. Lots of them, but insanely expensive.
- Back in 2019 SLS tried to snatch an Europa mission. Nice tried, but as soon as Congressman Culbertson retired, the proposal died.
So not really surprised SLS science missions have gone nowhere...

The ultra high expense of using SLS as a launch vehicle for a science mission far outweighs any possible advantage the SLS might supply by an order of magnitude. There are other launch vehicles that can do the same job far, FAR less expensively. SLS is stupid expensive. It will never fly a science mission - ever.

The same can be said for any other missions. The SLS is simply too expensive with a low launch cadence.

Sure a higher launch cadence would make it somewhat cheaper, but it will still be 'too expensive' for anything that has another choice.

It's built in to the design and no amount of flying will fix it.