SLS Program working on accelerating EUS development timeline

[TheRadicalModerate]

The next step, which in my opinion is less than a year away, is that US Congress, again under influence of the Boeing lobby, will force NASA to work EUS into the very center of return-to-the-Moon plans. Either by writing an integrated lander into law or writing the launching of the lander element on SLS into law (like how US Congress did with Europa Clipper).

All that has to happen for the implementation of that next step is for NASA to select the Boeing HLS proposal, and Artemis is stuck with Block 1B until the whole program collapses under its own weight.

But I suspect that there will be some serious congressional pushback on an architecture that requires launching two SLSes in rapid succession forever--even with the chairman of the Senate appropriations committee putting his thumb on the scales.  It's insanely expensive and requires introducing almost as much risk into EGS and other launch processing infrastructure as it takes out of HLS itself.

And Boeing isn't the only game in town any more.  SpaceX and Blue Origin both have some lobbying heft to them, and generate a lot of business for gulf coast states.  (Even Shelby can't ignore architectures that would expand the Huntsville BE-4 plant severalfold.)  Add to that NGIS, which I'm sure is counting on eventually getting some commercial resupply work to NRHO, and the old lobbying paradigm could break down.

Ultimately, I think Loverro is going to be faced with a choice between an insanely expensive double SLS launch, which carries a lot of political risk as Congress becomes bored with Artemis, and a more developmentally risky architecture that's much cheaper to launch on commercial components but a lot more complex to put together and service in NRHO.

It's never a good idea to bet against Boeing not getting its way in Congress, but the situation's a lot more complicated for them now than it has been in even the recent past.

[MATTBLAK]

Boeing has the SLS and they will get the EUS contract if and when it happens. If the HLS is fielded as a 3-stage design (my preference) launched on Vulcan etc, Boeing can still be a part of it all.

1: Boeing makes SLS & EUS. 2: Boeing has a stake in Vulcan. 3: Boeing can bid on at least one element of the 3-stage Lander.

If they want ALL the HLS as well, launched on another, entire SLS... One could be forgiven for thinking that Boeing doesn't just want a slice of the pie - they want the whole pie... It seems to me that wedding a single, one-week long human landing mission to an approximately $4 billion of launch costs, plus another $2 billion (at least) in spacecraft hardware, plus hundreds of millions in mission infrastructure... See where I'm going with this? When people find out that each mission to the Moon costs about $7 billion U.S. dollars - not to mention the big costs of developing Gateway - then someone in Congress and/or Senate is going to rebel. The human exploration of space should not be about spreading the pork and/or wasting money, when there would be a better, less costly way to do things. I know some will think I'm naive or missing the point - I'm not. I know how some of these politics work. But human lunar landing missions should not cost more than an Apollo J-Series landing mission, adjusted for inflation.

But removing the $2 billion dollar cost of an additional SLS launch from a $7 billion dollar mission would help a lot, but it would still hurt. The three launches of the separate Lander pieces would still cost in the neighborhood of a half-billion dollars or more. However, with the EUS in service and hopefully, better boosters for SLS later, the Orion launched part of the mission could bring a co-manifested payload of either a fresh Descent Stage or a refueling Tanker for the Ascent or Transfer stage. With a two-thirds reusable Lander system in operation, based at Gateway, long-term cost savings would eventually creep into the mission budgets. So we have to ask ourselves: which is better - removing the costs of an additional SLS launch per Lunar mission, or simplifying the architecture by reducing the number of launches per mission to 2x SLS?

[TheRadicalModerate]

Boeing has the SLS and they will get the EUS contract if and when it happens. If the HLS is fielded as a 3-stage design (my preference) launched on Vulcan etc, Boeing can still be a part of it all.

1: Boeing makes SLS & EUS. 2: Boeing has a stake in Vulcan. 3: Boeing can bid on at least one element of the 3-stage Lander.

If they want ALL the HLS as well, launched on another, entire SLS... One could be forgiven for thinking that Boeing doesn't just want a slice of the pie - they want the whole pie... It seems to me that wedding a single, one-week long human landing mission to an approximately $4 billion of launch costs, plus another $2 billion (at least) in spacecraft hardware, plus hundreds of millions in mission infrastructure... See where I'm going with this? When people find out that each mission to the Moon costs about $7 billion U.S. dollars - not to mention the big costs of developing Gateway - then some Congress and/or Senate is going to rebel. The human exploration of space should not be about spreading the pork and/or wasting money, when there would be a better, less costly way to do things. I know some will think I'm naive or missing the point - I'm not. I know how some of these politics work. But human lunar landing missions should not cost more than an Apollo J-Series landing mission, adjusted for inflation.

But removing the $2 billion dollar cost of an additional SLS launch from a $7 billion dollar mission would help a lot, but it would still hurt. The three launches of the separate Lander pieces would still cost in the neighborhood of a billion dollars. However, with the EUS in service and hopefully, better boosters for SLS later, the Orion launched part of the mission could bring a co-manifested payload of either a fresh Descent Stage or a refueling Tanker for the Ascent or Transfer stage. With a two-thirds reusable Lander system in operation, based at Gateway, long-term cost savings would eventually creep into the mission budgets. So we have to ask ourselves: which is better - removing the costs of an additional SLS launch per Lunar mission, or simplifying the architecture by reducing the number of launches per mission to 2x SLS?

That's a fair summary.

I'd only add that I don't think Boeing cares for a moment about landing the HLS contract--it's chump change to them.  What they do care about is locking in Block 1B and double the SLS cores that they would have otherwise.  Since they're the only company insane enough to bid that kind of system, that's what their bid is really about.

It's hard to imagine Starship imploding so badly that it's not good for at least hauling massive amounts of cargo from LEO to NRHO.  If that's the case, then you can take all of the HLS components you could ever dream of, toss 'em into the payload bay, and get everything for a mission to NRHO except the crew, for something around $200M (assuming $50M/launch and three tankers).

Maybe that's a good reason to use the Boeing architecture, because an AE/DE that doesn't have to rely on co-manifesting is huge, and can likely be put to a fair number of uses.  Then hosting it on Starship chops out the Block 1B flights, but leaves Boeing still with a Block 1 and an HLS stack per mission.  From there, a crewed Starship (even if you have to bring the crew up/down to/from LEO on an F9/D2), takes out the Block 1, and finally the full Starship flight profile finally gets rid of the HLS.

I doubt that's what Boeing would wish for in its wildest dreams, but it's probably on balance a lot more money than they'd make if they just waited for Congress to kill the whole program.

[MATTBLAK]

Part of me wants SLS killed stone dead, now. But the far more pragmatic me wants it to stick around until Starship/SpaceX does or does not succeed in its aims. If the Starship program tanks (I wanna be very wrong about that) the SLS Block 1B or 2 will be the class leader among the Super Heavy Lift programs. Other than political and financial obstacles; I don't see any technical hurdles for SLS's survival. It should be good at what it does. But if they are going to throw away a sh1t ton of beautiful hardware every time they launch; they should give it the best upper stage and solid boosters they can, to maximize that payload and at least partly justify that vast expenditure. A launch rate better than 2x per annum would help it's cause as well. 2x SLS launches per year, coupled with 2 or 3 commercial heavy lifters could build a Lunar Outpost in relatively short order.

And if both Starship and SLS went away - the Commercial Heavy lift launch fleet of (Roll Call) Falcon Heavy, Vulcan Heavy, New Glenn, Ariane 6 and H-3 (heavy-ish) could get a lot of mass into orbit fairly smartly, if need be. In fact, if you executed twinned launches of all these guys and asked China and Russia to chip in with 2x LM-5 and Angara 5 each; that would be enough for fair-sized Manned Mars Mission. And we really need Propellant Depot technology, Stat!!

And wake me when New Glenn begins testing. When's that supposed to be again?!

[jadebenn]

Boeing has the SLS and they will get the EUS contract if and when it happens.

They've had the EUS contract for quite some time now, though they'll only have flight hardware on order once the SLS block buy contract gets finalized.

[oldAtlas_Eguy]

At the moment both Boeing and NASA engineers who would otherwise be busy with SLS green runs need something to do.

[JohnF]

Lots of debate on this one huh ?, ..just fly SLS Block 1 until EUS has tested enough for crew, then throw a lander built by whoever into Block 1B, fly it all together to the moon ala Apollo, simple....cont. with debate, lol.

[MATTBLAK]

Block 1B isn't powerful enough to send both Orion and a fully-fueled Lander to the Moon; by that I mean low lunar orbit. Block 1B might be able to send an Orion and a completely unfuelled, lightweight Lunar Lander roughly Apollo LM-sized as a co-manifested payload to the Gateway at NRHO. So would a Tanker Module be there, waiting to fill up the Lander? Or would the Gateway be a Propellant Depot? See - this is why I prefer any Lunar Lander design as a three-stage version; so the Orion could bring along a fresh Descent Stage with it each time. Vulcan or Falcon Heavy could have sent a Transfer Stage and Ascent Stage out to the Gateway first. The new Descent Stage could then be integrated with the Transfer and Ascent Stage for a fresh mission. Later flights before humans return could be Commercial launches that bring propellant shipments to refill the Ascent and Transfer Stages.

This frees the Lunar architecture from the tyranny of having to pay for and wait for another $2 billion dollar SLS to be built. Save the SLS for only launching crewed Orions or very occasionally large cargo. One version of 'large cargo' could be a fully fueled and integrated 3x stage Lunar Lander to replace one that had finally worn out!

[dglow]

So in the dual-launch, Orion-on-ICPS + HLS-on-EUS, the two will meet up in NRHO, even sans Gateway. Whereas if both launches were on Block 1B they could/would meet in LLO.
Is that correct?

[TrevorMonty]

So in the dual-launch, Orion-on-ICPS + HLS-on-EUS, the two will meet up in NRHO, even sans Gateway. Whereas if both launches were on Block 1B they could/would meet in LLO.
Is that correct?

EUS isn't designed to survive 3-4 day trip from TLI to LLO. Has DV but not life. It may e possible upgrade.

[TheRadicalModerate]

So in the dual-launch, Orion-on-ICPS + HLS-on-EUS, the two will meet up in NRHO, even sans Gateway. Whereas if both launches were on Block 1B they could/would meet in LLO.
Is that correct?

EUS isn't designed to survive 3-4 day trip from TLI to LLO. Has DV but not life. It may e possible upgrade.

Even if you could extend the stage life of the EUS, it and Orion together still can get less than 3t of co-manifested payload to LLO and leave enough prop for Orion to get back to TEI.

The Universal Stage Adapter is heavy.  Assuming a 400 kg PAF, it lops off almost 4.8t from what you can co-manifest.  If you could find a way to get rid of it before TLI, things would be better, but then you'd be flying Orion eyeballs-out and relying on the PAF, the co-manifest, and the NDS to keep the Orion stable during the burn.  Not gonna happen.

[dglow]

So in the dual-launch, Orion-on-ICPS + HLS-on-EUS, the two will meet up in NRHO, even sans Gateway. Whereas if both launches were on Block 1B they could/would meet in LLO.
Is that correct?

EUS isn't designed to survive 3-4 day trip from TLI to LLO. Has DV but not life. It may e possible upgrade.

Even if you could extend the stage life of the EUS, it and Orion together still can get less than 3t of co-manifested payload to LLO and leave enough prop for Orion to get back to TEI.

The Universal Stage Adapter is heavy.  Assuming a 400 kg PAF, it lops off almost 4.8t from what you can co-manifest.  If you could find a way to get rid of it before TLI, things would be better, but then you'd be flying Orion eyeballs-out and relying on the PAF, the co-manifest, and the NDS to keep the Orion stable during the burn.  Not gonna happen.

Interesting, and thank you both. So EUS only solves Orion's 'LLO problem' by enabling it to be paired with a beefier ESM. Where the current ESM's size/capability has been driven as a function of Orion's mass and ICPS's limitations. Yes?

[TheRadicalModerate]

See - this is why I prefer any Lunar Lander design as a three-stage version; so the Orion could bring along a fresh Descent Stage with it each time. Vulcan or Falcon Heavy could have sent a Transfer Stage and Ascent Stage out to the Gateway first. The new Descent Stage could then be integrated with the Transfer and Ascent Stage for a fresh mission. Later flights before humans return could be Commercial launches that bring propellant shipments to refill the Ascent and Transfer Stages.

This is a bit O/T, but I do think it's important to note that a big chunk of the EUS's appeal is its ability to co-manifest, and therefore figuring out what it should co-manifest for HLS is pretty key to whether it's truly essential to Artemis or not.

I don't think you want to co-manifest the DE in a 3-stage architecture.  There are three main reasons:

1) I don't think the Gateway has a prayer of occurring before the first versions of HLS have to fly.  So we're talking about free-flying assembly of components, with no Gateway assistance.

2) Think about the sequence for attaching a DE to the HLS stack.  You have two constraints here.  First, the AE has to be the top of the stack, because you have to board the crew, and you don't want to do that until the entire stack is assembled.  Second, the DE has to be directly below the AE.  That pretty much fixes the order of elements as, from top to bottom, AE-DE-TE.  If you co-manifest the DE, you have to leave the AE and TE separately free-flying, then assemble all three while the crew sits there in the Orion, wondering if it's all gonna assemble properly.  So, unless you want to incur that kind of mission risk, that restricts you to co-manifesting either the AE or the TE.

3) You really want to get as much impulse out of the co-manifested element as possible.  I'm assuming that the free-flyers need to use storable prop, because they're likely going to be in place weeks or months before the Orion/co-manifest shows up.  envy will no doubt disagree with me on this, but I don't think that the low-boiloff cryogenic technologies we're working on are sufficiently mature to use in HLS, at least for the kind of mission lives we're talking about.

But the co-manifested piece probably can be cryogenic, because it's in a fast transfer and because it can be encapsulated by the Orion, USA, and EUS, which can act as a sunshade for a decent part of the trans-lunar coast.

I know that there's been talk about a reusable TE, but it's nonsense.  The TE is the least expensive component, and the only way to refuel it is with something that looks an awful lot like another (expendable) TE.  You should assume that TE's are expendable, and therefore are good candidates for co-manifesting.

Finally, TE's will have the lowest structural mass fraction (SMF).  They don't need landing legs.  They don't need gimbals for TVC.  They don't need fancy radars, or landing-shock-resistant components.  They don't have weird restrictions on their center of mass.  And most importantly, they don't have to be crew-rated for a landing, only for providing a certain amount of dumb delta-v.  Low SMF means more impulse, which is what you want.

That said, there's also a case to be made for co-manifesting the AE.  It's the simplest docking configuration: once you've got it extracted from the USA and docked to the Orion's nose, Orion just docks it with the DE/TE stack (docked/mated before you ever launch your $4B+ of SLS, Orion, and co-manifest) and you're good to go.  It's also arguably the component that you'd least like to have sitting in space for long periods, simply because it's the piece where you really, really don't want anything to fail.

But that makes it small.  If you assume that EUS can take 41t to TLI (which is frankly pushing it), you've got a 26.7t Orion (with crew), a 4.4t Universal Stage Adapter, and a PAF that's likely 0.4t, which means that your max co-manifested payload will be something like 9.5t.  If you assume a pressure-fed storable engine (which you should, because it's reliable, does landing aborts quickly, and has no boil-off risk on the very hot daytime lunar surface), the lower Isp limits your burnout mass + up mass + crew to 3820 kg, which is... more than an Apollo ascent stage, but not by very much.

And it's obviously not the element with the smallest SMF.

With a co-manifested pumped methalox TE (Isp=360) and an SMF of 10% and a second "crasher" TE with pressure-fed storables (same SMF), I can get a DAE from NRHO and back with 4.9t of burnout mass, 0.5t of surface payload, with 0.3t of crew added in NRHO.  Bear in mind, though, that this is also the lander, so you're adding landing gear and gimbals and whatnot.  It's still likely a bit more luxurious than the co-manifested AE, but it's close enough that the reduced complexity in docking might make the CMAE a better choice.

[TheRadicalModerate]

Interesting, and thank you both. So EUS only solves Orion's 'LLO problem' by enabling it to be paired with a beefier ESM. Where the current ESM's size/capability has been driven as a function of Orion's mass and ICPS's limitations. Yes?

The bottom line is that even SLS Block 1B can't put as much stuff into TLI as a Saturn V could.  A Block 2 will, but that's further out.

[ZChris13]

Interesting, and thank you both. So EUS only solves Orion's 'LLO problem' by enabling it to be paired with a beefier ESM. Where the current ESM's size/capability has been driven as a function of Orion's mass and ICPS's limitations. Yes?

The bottom line is that even SLS Block 1B can't put as much stuff into TLI as a Saturn V could.  A Block 2 will, but that's further out.

Are those TLI numbers for Block 2 coming from Congress or from the options being considered (the advanced boosters) (also, which advanced boosters)

[TheRadicalModerate]

Are those TLI numbers for Block 2 coming from Congress or from the options being considered (the advanced boosters) (also, which advanced boosters)

I just grabbed Ed Kyle's numbers, which seem to be from the 2014-vintage SRBs.

I'm viewing Block 2 as science fiction, pretty much.  I'll be very interested to see what tweaks they make to EUS, though.  Fairly minor increases in co-manifesting capability make big differences to potential HLS architectures.

[jadebenn]

I think you'll find this useful.

I'm making the (fairly safe) assumption the jaw-dropping 43t TLI (not counting reserves) is Block 1B with all the upgraded components and bells-and-whistles, so not the one available for initial HLS. Still, corroborates what you're saying about the impact of the stage adapter on payload.

[TheRadicalModerate]

Do you have the source for that diagram?

I would assume that you'd get all the bells and whistles possible in the reworking of the EUS that's currently ongoing, and they'd show up in the first Block 1B.  If you can really do a 13t co-manifest, that changes a lot of things.

[Coastal Ron]

In mid-2018 NASA was showing:

Payload to TLI/Moon for Block 1B Cargo - 37-40 t (74k-81k lbs)

Has the EUS really changed that much in just a year and a half?

[MATTBLAK]

A 13 metric ton co-manifest would allow the Orion to bring with it a new Transfer stage each time, or a Tanker module to top up either a Transfer stage or Ascent stage. A separate Commercial launch would have to bring a propellant load for an Ascent or Transfer stage, or a fresh descent stage if the Lander design is three-segment. Which I think would be wise; to avoid another $2 billion dollar, schedule-pushing SLS launch of an integrated 2 stage, 40+plus ton Monster LM.

Is the Orion adapter for SLS going to be a lightest possible composite structure? I admit to not knowing much about it. The Apollo LM adapter weighed more than 4,000 pounds - 1,840 kgs and was made of aluminum.