Last week, when NASA announced that they were picking Blue Origin’s National Team to develop a sustainable human lander for the Artemis V mission, what surprised me wasn’t the selection, but the fact that I’ve come around to really liking the decision.
While it’s still recent enough to be relevant, I wanted to share some thoughts on Blue Origin’s updated human lander architecture, why I think this was the right selection in spite of my feelings about their original concept, thoughts on the execution challenges they’ll face, and some of the interesting future possibilities having two fully-reusable lander architectures may open up for NASA. But first, you may be wondering why I was so surprised that I would end up liking Blue Origin’s lander architecture.
Why I Wasn’t A Fan of Blue Moon 1.01
I hope I don’t offend any of my friends who work or worked at Blue Origin by saying this, but if you had to summarize my initial reaction to the National Team’s original HLS lander concept, I would’ve used the word cynical.
It felt cynical, because rather than trying to come up with the best solution for affordably and reliably bring people to/from the lunar surface, they seemed instead to be regurgitating exactly what they thought NASA wanted to see. NASA had a reference mission concept that was a complex, fully expendable system with three stages — an in-space tug, a descent element, and a separate ascent element, so that’s what they had. Blue Origin was a relatively unproven space contractor, so they added not one, but two aerospace primes to their team. Which also happened to maximize the number of congressional districts their project would have work performed in2. It almost felt like they weren’t even trying to win, so much as guarantee that they’d be one of the two solutions picked3. While in theory at least some of the elements in Blue Moon 1.0 could be refueled and reused, some components like the massive lander descent stage had no easy path to future reuse.
In contrast, the Dynetics ALPACA design was a creative approach that seemed to be genuinely trying to provide NASA with a good way of getting people and cargo to and from the lunar surface. By the end of the base period, they had shifted to a single-stage lunar lander concept that leveraged in-space refueling, and had a clear pathway to full reuse. The low-slung central crew/cargo attachment point allowed easily delivering crew to/from the lunar surface as well as delivering large cargo modules, without needing multi-story ladders or elevators. The low CG meant that it could likely land on rough terrain with a lower odds of tipping than a design like Starship HLS. It did have the teensy problem that at the time proposals had to be submitted, the design’s mass budget didn’t close yet4, but they did eventually close the design, just not in time for consideration in the Option A evaluation.
Anyhow, suffice it to say, that going into last week’s HLS Sustainable Lander Development announcement, I was really rooting for Dynetics to win, and didn’t have a very high opinion of Blue Origin’s lander concept. So, when Administrator Nelson announced the National Team had been selected, my first reaction was pretty strong disappointment.
I’m glad I was too busy taking notes from work to tweet my immediate hot take, because by the end of the call, my opinion had shifted pretty dramatically.
Why Blue Moon 2.05 is a Dramatic Improvement Over v1.0
It took the press conference a while to show any details about the new design, but when they unveiled the Blue Moon 2.0 lander, I almost did a double take. The design was superficially similar to the original design, but you pretty quickly noticed some pretty significant differences. Was I seriously seeing a bottom-loader single stage design?
I never got around to blogging about what I call bottom-loader SSTO landers, but it’s an idea I first learned about almost 20 years ago with t/Space’s CXV Stage 2 concept from their Concept Exploration & Refinement study final report6. It’s one of my three favorite Unorthodox Reusable Lunar Lander Concepts that I’ll hopefully get more chance to blog about in the future. Needless to say, when I saw that, I perked up and started paying real attention.
If I had to summarize the highlights we could glean of the proposed Blue Moon 2.0 lander architecture, I’d point out three key features:
- Bottom-Loader SSTO Lander: Crew or cargo pod on the bottom, propellant tanks on top. Enables easy surface access without cranes or ladders. Keeps the CG low for reduced tipping risks. Keeps the load paths for the rocket higher efficiency. Provides the best thermal isolation between the warm parts7 and the parts that want to be kept really, really cold8. This is the part that Blue Origin would be developing
- Reusable Cis-Lunar Refueling Tug: While they never showed any pictures of the tug, this element would bring LOX and LH2 propellant from LEO to NRHO to refuel the lander, and return to be refueled again for reuse. This is the part that Lockheed Martin would be developing.
- Reusable From the Start and ISRU Compatible: By going to a single-stage architecture, there’s a clear and easy path forward to refueling — initially in NRHO using tugs coming from LEO, but eventually also on the lunar surface9. Also, while LH2 is harder to handle than Methane, LOX/LH2 can be derived readily from lunar water ice sources10, enabling a switch over from terrestrial to lunar sourcing once ISRU is proven out/debugged/scaled up.
In short, Blue Origin responded to their Option A loss in 2021 by significantly improving their offering to NASA, offering a solution that was innovative and actually worth funding.
Why I think Blue Moon 2.0 Was the Right Call
I’m still a fan of Dynetics’ ALPACA and LLAMA concepts, and I hope they find some way to see the light of day. But given what we know now, I think the Blue Moon 2.0 concept was the right call for NASA, and not a politically-motivated decision, or one that only won because a space billionaire bought his way to success.
First, and most importantly, I think Blue Moon 2.0 helped close the innovation gap between the National Team and Dynetics. Blue Moon 2.0 captures many of the benefits that ALPACA brought to the table, including: lower CG for better landing on uneven terrain, crew/cargo located close to the ground for easy ingress/egress and loading/unloading, ability to deliver significant cargo mass to the surface, and a single-stage design with a clear path to full-reusability. In some ways it was better than ALPACA, by providing a cleaner load path and easier thermal isolation of cryogenic tanks from heat sources, a propellant combo that had an easier path to 100% sourcing from lunar ISRU, and a more developed fully-reusable cislunar tanker concept11. There were some relative drawbacks like the challenges of LH2 storage, and the potentially smaller available cargo volume12, but overall they did a good job of narrowing or closing the gap with Dynetics’ solution.
Second, there seemed to be far less zip-code engineering this time around13. There are multiple team members still, but each of them makes logical sense, not just as a way to get more congressional support.
Third, while there’s very real execution risk for Blue, since they haven’t flown anything anywhere near this complex, Dynetics carries similar risk, so it’s not really a discriminator.
Fourth, while Bezos’s willingness to subsidize the price to NASA probably made a difference, it was far from the only consideration, and in my opinion was probably more of icing on the cake. In addition to closing the innovation gap with Dynetics, it sounds like Blue did a better job of convincing NASA that they had a design that unambiguously closed technically. If Dynetics had still had the clearly superior concept, and if they had done a better job of making it unambiguous that they had a design that closed for all of NASA’s needs, I think they would’ve had a decent chance of winning, even with being more expensive to NASA.
In the end, for all of these reasons, I think NASA made the right call. That said, while I doubt it will happen, I hope Dynetics finds some way to get their concept fielded14.
But Can Blue Deliver?
This is where I have the strongest reservations. While Blue has now laid out an innovative and exciting architecture that’s worthy of being funded, a concept is only as good as the organization tasked with executing it. And frankly, people have reasons to have reservations about Blue Origin’s ability to execute on a project this complex. Whether you look at how late the BE-4 engines were in development, how long it took New Shepard to transition from flight test into operations, or how long New Glenn has been taking to make visible progress, there’s definitely room to worry that Blue sometimes take the Graditim part of its slogan more seriously than the Ferociter part. One thing Blue Origin has made me realize is that while I’ve had too much experience with having too little money, that there are real risks in having too much money, that has too few requirements for demonstrated traction tied to it.
It’s an open question if Blue can change its company culture and processes quickly enough to be able to deliver on an ambitious project like this on a tight schedule. I hope they can succeed at that evolution though, because if both the National Team and SpaceX are successful, it could lead to a very exciting new world.
What If They Are Successful?
If both SpaceX and the Blue Origin National Team are successful, we enter a really interesting world. As Eric Berger pointed out in this Ars Technica article today that I was quoted in, both architectures are now based solidly on the use of reusable launch, in-space cryogenic storage and transfer, and in-space reuse. As I pointed out in the intro to my unfinished series on Unorthodox Reusable Lunar Lander Concepts, a fully-reusable lander architecture brings a lot of advantages, beyond the obvious ones of cost savings:
- Lower Marginal Costs: While you’ll still have some fixed costs associated with the lander infrastructure, the marginal cost of such an architecture drops dramatically, since you’re not having to build new lander or in-space tug hardware for every mission.
- Throttleability: Once you have a stable of multiple reusable landers, where there aren’t any major expendable components, it becomes a lot easier to throttle up or down mission tempos based on budget availability. If you have a year or two that you need more money to fund say Mars system development, you can throttle down to a lower ops tempo without risking losing the capability, unlike what happened during Apollo.
- Easier International Involvement: While Starship and New Glenn should theoretically be cheaper than any other launch source, if NASA is paying for those launches, it’s still a cost. But with a distributed lift/tanker architecture, it becomes more feasible to allow international partners to contribute propellant or crew or cargo launches to LEO as their part of the mission. Even if their rockets are more expensive, if NASA isn’t having to pay for those launches, it lowers the cost to NASA.
In addition to those benefits, a fully-reusable Cislunar tug, like what LM is proposing as their part in the Blue Moon 2.0 architecture, opens up some very interesting possibilities. Once you have a reliable way of getting from LEO to NRHO and back reusably with propellant, it’s a relatively straightforward upgrade to add the ability to ferry crew and/or cargo instead of or in addition to propellant. And since Blue will have already developed a crew cabin that’s safe for up to 30 days on the lunar surface, using a derivative of that as a crew pod on the reusable Cislunar Tug isn’t a crazy option. We don’t have hardly any details on LM’s concept, so there’s a chance they might have something in mind that wouldn’t be able to do the LEO-NRHO-LEO loop with crew or cargo, but most of the most likely options should be fairly straightforward to do that.
Once you have the ability to move crew, cargo, and propellants around from LEO to NRHO with a fully reusable system, do you really need SLS and Orion anymore? The vast majority of the budget being attributed to Artemis was the development and operation of SLS and Orion, but they’re only really capable of one mission per year. If you replaced them with distributed lift and reusable Cislunar tugs for crew/cargo out to NRHO, you could probably enable upping the lunar mission tempo dramatically, while freeing up money for developing lunar surface habitation and ISRU payloads. It’s still a longshot politically, but if SpaceX and the National Team are successful, we could be living in very interesting times.
Jonathan Goff
Latest posts by Jonathan Goff (see all)
- NASA’s Selection of the Blue Moon Lander for Artemis V - May 25, 2023
- Fill ‘er Up: New AIAA Aerospace America Article on Propellant Depots - September 2, 2022
- Independent Perspectives on Cislunar Depotization - August 26, 2022
- My nickname for the National Team’s original Human Landing System concept from 2020.
- A practice sometimes called Zip-Code Engineering
- At the time, most of NASA’s comments had made it sound like they were going to downselect from three providers to two. Almost nobody I had spoken with in NASA or industry had expected that they would be willing to go with just one HLS provider.
- The Option A proposals were due around half-way through the Base Period, shortly after Dynetics had shifted from their drop-tank configuration to their single-stage configuration.
- Also my nickname, not theirs
- For a trip down memory lane, check out theirs and the other studies at: https://www.nasa.gov/missions/solarsystem/vision_concepts.html
- Where people, electronics, engines, and cargo are.
- The cryogenic propellant tanks
- As a big fan of refueling early, and refueling often, I’d also note that topping up in LLO on the way to/from NRHO could theoretically provide a pretty big performance boost
- I know some people will point out that the LCROSS data suggests that there is some CO2 and hydrocarbon ice in polar deposits, but I’m still pretty skeptical that there will be as much of it available as there will be of regular water ice. I know at least some of the data that people tend to quote was based on the original uncorrected data, and IIRC the corrected data suggested that such carbon-bearing ices were far less common relative to water than the original uncorrected data suggested.
- My one real disappointment was that they didn’t show more about this cislunar tug. From the discussion, it’s clear that this was an explicit and significant part of their proposed concept, but it’s really unclear exactly what this looks like, how it’s being reused, etc.
- They didn’t get into deep detail on exactly how the cargo would be stored. From the picture it looks like the engines might be under the crew pod, so it’s not clear if the crew pod is removable or if they have to have a seperate cargo variant. And for the separate cargo variant, it’s unclear exactly where the cargo needs to fit in. The volume of the crew pod looks like it’s on the order of 70-80m^3, which would be hard to usefully fit 20-30mT of cargo into.
- To some extent, I think Dynetics also reduced the amount of zip code engineering in their concept as well.
- Either by doing a subscale suborbital surface hopper transport system, or by partnering with a serious foreign partner that wants to be in the lander game, or some other way.
Is it known where SpaceX and Blue Origin are going land in south lunar polar region?
Or what needs to done before these sites are selected?
In regards to LH2 storage on orbit, over 10 years ago I heard a rumor (from a pretty reliable source) that there was a classified program that had an improved cryocooler, suitable for keeping LH2 cold on orbit. Look at who is doing the tug. Look at their past experience with classified programs. Maybe the cryocooler is in that design.
gbaikie,
I haven’t been paying close enough attention to know which of the Artemis landing sites have been selected so far, and which are still TBD.
ech,
That seems believable. Most IR telescopes need to be chilled to cryo temps to function correctly, and the DoD and IC probably use a fair number of such telescopes looking back at Earth. In the past, AIUI, some Earth-Imaging IR satellites used Liquid Helium dewars to keep chilled, but that has a finite lifetime. I could imagine them wanting to replace those with cryocoolers that could run indefinitely. AIUI, people have some pretty low temperature cryo coolers here on earth too. So, I’m not sure, but its a plausible theory. I didn’t think the cryo coolers necessarily were a showstopper, just that the overall challenge of making a practical LH2 ZBO system was non-trivial.
~Jon
I tend to agree that National Team Mark II has done a good job, and they likely have a system that can be competitive with SpaceX for quite a while.
One significant problem with the bottom-loader design: In the HDL configuration (the cargo version of the lander), the landing leg struts and (to the extent that it’s different) load-transmission system severely limit the dimensions of the payloads that can be off-loaded. If everything’s engineered for New Glenn, then the outer mould line can’t be more than 6.3m in diameter. The artwork shows four landing legs, which means that any payload can only be ~4.3m wide, with a ~4.3m length. Not the end of the world, but definitely a limitation.
I assume that the old Blue Moon system of davits is now gone, and the lander will deploy payload via a ramp. That should eliminate and significant restrictions on payload height.
I’m still intensely skeptical about the ability of **any** lander system being reusable in the near-term, but Blue Moon, with its low-slung engines, will be especially vulnerable to FOD and dust contamination. I guess that Blue could do something weird and mount landing thrusters with high cosine losses on the top of the LH2 tank, similar to what Lunar Starship will probably do with the waist thrusters, but it’s gonna be a problem. And proving that a vehicle that’s returned to NRHO is safe to reuse is going to be extremely difficult.
I’m very interested to see LockMart’s design for the Cislunar Transport–especially since Coulouris said that it would launch on a New Glenn. Several big questions:
1) If it’s really reusable, does it return to LEO propulsively, or are they going to aerobrake in back to LEO over a few tens of orbits? I did a back-of-napkin that convinced me that 20m/s of aerobraking delta-v per pass will get the CT back to LEO in about 75 days. Given the execrable Artemis cadence, that should be fine.
2) Does the CT return to LEO via fast transit (which costs about 475m/s) or via some kind of a reverse BLT, which likely only costs 100m/s? If reverse BLT, a shallow aerobraking might not work, because the BLT apogee is so far out that engineering the apogee reduction via aerobraking will get dicey.
3) Are they planning on refueling the Blue Moon in a single sortie, or will it require multiple trips? I’m guessing that NASA will frown on multiple RPODs and refuelings of crew-rated hardware, if for no other reason than risk management. But a CT capable of doing everything in a single trip will require ~120t hydrolox tanks¹ with ε=10% and RL10-like Isps, which is big enough that the New Glenn fairing will force some weird choices. More specifically, you can’t put the engine bell near the PAF and still have enough volume for 5.9:1 hydrolox. You could mount the whole CT upside-down, with the engine and thrust structure sticking up into the ogive/nose section, but then getting the center of mass low enough, and the structure stiff enough, will get interesting.
4) Does this mean that LockMart is really the buyer of ULA, and will they start from the Centaur V for the CT? If so, I’m sure that Tory would be happy to show them how to put IVF back into the Centaur V, effectively turning it back into something close to the original-concept ACES. But then they’re stuck with multiple sorties to fully refuel the Blue Moon.
5) What non-HLS markets will LockMart go after with the CT? I’m guessing that commercial GEO refueling, and a wide variety of DoD/NRO cislunar applications are low-hanging fruit. And they could bid the fueling for DRACO with the CT as well. This also feeds into questions about the actual size of the tanks, and the one-vs.-multiple trip question.
____________
¹There’s also the issue of Coulouris’s “north of 45t” statement for Blue Moon’s wet mass. When I work out the hydrolox for the stated 16t dry mass, it’s 41.8t for polar and 46.4t for equatorial. I’m assuming that the “north of 45t” really meant that it could launch partially filled on a New Glenn, because otherwise it doesn’t come close to closing.
I’m still intensely skeptical about the ability of **any** lander system being reusable in the near-term, but Blue Moon, with its low-slung engines, will be especially vulnerable to FOD and dust contamination. I guess that Blue could do something weird and mount landing thrusters with high cosine losses on the top of the LH2 tank, similar to what Lunar Starship will probably do with the waist thrusters, but it’s gonna be a problem.
This *is* a valid concern, and it occurred immediately to me as well.
That said, it’s an issue that NASA is pretty obviously alive to, given the tech study they have commissioned into it with SpaceX, for example . . . to say nothing of the latest work done by Phil Metzger (https://arxiv.org/abs/2305.12234). I simply *have* to think there were some serious discussions with both Blue Origin and Dynetics about this over the last year, given the obvious vulnerability of their architectures to this. How will they shield the engines and crew compartment? Will they supplement with high-mounted thrusters, like Starship is doing? Have they calculated plume dynamics for ascent and descent?
Alas, whatever the answers turned out to be, they are not sharing them publicly yet.
Throttleability: […] If you have a year or two that you need more money to fund say Mars system development, you can throttle down to a lower ops tempo without risking losing the capability, unlike what happened during Apollo.
We could think even more expansively about this, with the the example of SpaceX’s aggressive use of Crew Dragon for commercial clients as our model. Let’s assume that, before long (say, by the early 2030’s), both SpaceX and Blue Origin/Lockheed can indeed put in place alternative transport capabilities from LEO to lunar orbit. At that point, you have not only opened the door to third parties paying to provide propellant or cargo, but even entire lunar missions! After all, the whole point of HLS for the vendors is that they get to keep and operate these architectures for clients other than NASA, to help amortize their development costs (and eventually, make profits!).
Say a mid-rank space country (say, UAE, South Korea, Saudi Arabia, Italy, whatever) is looking for a way to make a mark in space without breaking the bank to build their own lunar architecture. Just to spitball, let’s say the full bill for a lunar mission is half a billion dollars. That covers transport to and from LEO, transport to and from lunar orbit, the use of the HLS for a short lunar mission, propellant launches, consumables, and training. That’s far from an unattainable price tag for “sovereign” clients, especially if two or more team up to spread the cost. This keeps the ops tempo of the architectures up, and experience and improvement of operations and systems, at periods where NASA has to cut back.
After all, Jared Isaacman can’t do it all.
I don’t see the point in a re-usable lander to support the Artemis mission tempo of once every two, or or three, or more, years. Why spend billions on a re-usable that you will never re-use? Does anyone else see this?
Other than the free money aspect, why would any aerospace contractor want to bother? Once New Glenn and Starship prove themselves out, SpaceX and Blue Origin will surely create their own mission architectures for beyond earth orbit.
“I don’t see the point in a re-usable lander to support the Artemis mission tempo of once every two, or or three, or more, years. Why spend billions on a re-usable that you will never re-use?”
–Artemis 5 (2029) is planned to be the third crewed lunar landing, which will deliver four astronauts to the Gateway Space Station. The mission will deliver the European Space Agency’s ESPRIT refueling and communications module and a Canadian-built robotic arm system for the Gateway. Also delivered will be NASA’s Lunar Terrain Vehicle. Launch is scheduled no earlier than September 2029. The mission will also be the first to use Blue Origin’s Blue Moon lander to bring astronauts down to the moon’s surface. —
https://en.wikipedia.org/wiki/Artemis_program
So, before this is Starship and one could call this a reusable lunar lander, but you could also it a land able lunar base.
The main thing about Starship is it’s vehicle to land on Mars, but it could land on the Moon. So first, reusable lunar lander is the Blue Moon lander, and going to have started
making Gateway by then and NASA is planning lunar outpost after this.
And one could say, Starship and Blue Moon lander could be considered experimental rather than operational. If they fly and they work, then they will be used for operational missions. It seems Starship might be used for lunar work, if you want a lot payload put on the Moon. And many countries are signed on to Artemis accords, and some might make their own lunar lander or use the Blue Moon.
There not much sense in building the gateway or an lunar outpost, without using it.
Also seems to be some doubt SLS will be still flying after 2029.
It might not even get to 2029.
It’s slightly possible that the Moon is a lot of mineable water.
And what I mean by a lot mineable water, is that within 10 years of time, one
could be mining 1 billion tonnes of water per year.
In comparison to Mars, mining 1 billion tonnes water per year within 10 years
is not a lot of water, rather it’s one of the requirement for Mars to be habitable planet.
Or can’t do this, don’t have settlements on Mars. Or it’s assume there is enough water
on Mars or we wouldn’t call it the most habitable planet other than Earth. We assume
there are trillions of tons of water. But one could have tens of trillion of tonnes of water on Mars and not have mineable water which can allow you to mine 1 billion tons per year.
In terms of the Moon I tend to focus on minimum amount of water in needed, which I would say is around mining 10,000 ton within 10 years, and starting out doing about 100 tons of water and rapidly increasing amount mined per year.
But suppose there was a lot mineable water on the Moon, and it’s possible you mine as much as 1 billion tons within 10 year- assumes there are years thereafter of mining 1 billion tons or more per year.
Or Africans are drawing 2.4 billion tons [or 2.4 cubic km} of fossil water from the Sahara desert- have been doing for more than decade and we continue to do for decades.
Anyhow to do this on Mars, you have make lakes.
And if had a lot mineable water on the Moon, you could produce 1 billion tons per year, you also have to make lakes or one call them deep swimming pools.
On Mars you mine this much water to make desirable real estate and to make water cheap enough {$1000 per ton- or less}. And this doesn’t really apply to the Moon- though a deep swimming pool would nice thing to have for an hotel. So hotel could under water,
and people could swim in the pool. But if going mine that much water, you have store it
somehow.
Anyhow the issue is the potential mine billion tons per year due to there being a lot of mineable water on the Moon, but there is no apparent immediate need to make water priced at $1 per kg.
What could a need is you were exporting lunar water and had export market for 1 billion tons of water per year, and then don’t need lakes or very many hotel swimming pools.
So if the was a lot mineable water on the Moon, it seems one would be making a lot nuclear powerplants. And nuclear power plants would be cooled by water and they could be under water and these could provide electrical power to make chemical rocket fuel but
you need them to provide power to make and power mass drivers which could export
the water.
So, it probably take longer than 10 years to make the infrastructure to export water, so could mine as much a billion tons in 10 years, but might reach 1 billion tons within say 30 years when there market demand for it.
Whereas with Mars, the more water are make, the more market demand {more real estate] you have.
It’s unlikely the Moon has a lot water, but if it did, the Moon would probably export water to Venus orbit.
And if have settlement on Mars, there will be a lot mineable water, and like the Moon with a lot water, you export billion of tons water to Venus orbit {and that also requires
mass driver} but Mars will also grow food and can export food everywhere in solar system including Venus orbit.
But the Moon may not have any mineable water- in sense it can’t reach 10,000 tons water per year within 10 years of time.
The elimination of powered cranes and lifts is a big positive in my opinion. Any fault or excessive wear could leave people stranded. If a piece of equipment is being moved and a crane stops midway, there would need to be a way to ‘cut the ropes’ and just sacrifice that gear if it would mean losing the ability to get back into space if it can’t be freed. Even if a crane is useful, there should be a climbing option just in case.
I don’t see the need to make everything reusable and if the mission cadence is very low, it might not make any sense at all. It would be good to see anything that is intended to be left on the moon be constructed in a way that it can be disassembled and shares as many parts as possible with all types of craft that could be used. The parts that aren’t used in other landers would be best to be constructed to the extent possible out of easily separated materials or sub-assemblies that could be used in the future. I can see good arguments to having cargo, personnel and tanker variants of landers. It might be that only the manned craft that are reusable. A tanker might trade the mass added to making it reusable into a mechanism that can be deployed that turns it into a tanker truck so if it’s prepositioned in advance, it can be driven to where it’s needed if a following flight isn’t exactly where planned or just to facilitate connecting transfer hoses to shift the fuel.
All of the technology that will be required that isn’t already proven makes me concerned about the timelines. It’s also going to mean that if any item(s) wind up being more difficult and time consuming to finish will be adding age to the components that are ready for use. In 5 years time, the technology incorporated in the launch vehicles may have to be completely revisited due to vendors discontinuing parts. An example is the Magnetic Core Memory that was used in the Shuttle. By the end of the program the ladies that used to wind the cores were almost all gone and engineering modern memory into the system would have been a gargantuan task that would lead to a much larger change than just the memory to make work.
As far as water and other ISRU, it’s important to be on the moon doing it before making any detailed plans and especially before relying on it. Anybody that’s worked on the leading edge knows how often the unknown scraps the best laid plans. If you expect to grow food on Mars, don’t count on it until you do, at scale. Need to mine water on the Moon to use in creating propellents and other products, don’t count those chickens before they hatch either. All of these things are a reason I’d like to see non-reusable and simple landers so several experiment packages can be sent in advance to be tested when a crew arrives. Perhaps an empty cargo lander can be fitted out to be used as habitat/emergency shelter.