HLS Option B and the Sustaining Lunar Development Phase (Appendix P)

[TheRadicalModerate]

Sorry, there was a typo in my reply (which I have now fixed). In your original message, you spoke of a second option B lander in parenthesis which got me confused.

These landers have yet to be assigned to a mission but presumably Option B would be part of the Artemis V mission which is scheduled for 2027. The Appendix P lander would be part of Artemis VI in 2028 (if it is ready). This assumes that Artemis IV is a Gateway only mission. I am still hoping that NASA changes its mind on that.

See the schedule for the Artemis missions at this link:
https://arstechnica.com/science/2022/06/we-got-a-leaked-look-at-nasas-future-moon-missions-and-likely-delays/

See also page 7:
https://www.nasa.gov/sites/default/files/atoms/files/fy23_nasa_budget_request_summary.pdf

So that would be:

Non-Artemis:  LSS #1, used for Option A uncrewed test.
Artemis III: LSS #2, used for Option A crewed mission.
Artemis IV: LSS #3, used for Option B initial crewed test
Artemis V: LSS #3, refueled in NRHO for first operational Option B crew mission.
Artemis VI: Some App. P vehicle.
Artemis VII: LSS #... 3?, refueled in NRHO for second operational Option B crew mission.

We have no idea how many missions per spacecraft will be feasible.  Presumably, the minimum to claim "sustainability" is 2.

I still have this feeling that dust is going to severely limit the number of missions per spacecraft until there's an architecture that can land on Earth between missions for a thorough cleaning/refurbishment.

[sdsds]

Is it unreasonably hopeful to suggest the Option A crewed lander (the actual flight article, not just the design) would meet the Option B requirements if it were refilled with propellant somewhere in the cis-lunar vicinity?

[TheRadicalModerate]

Is it unreasonably hopeful to suggest the Option A crewed lander (the actual flight article, not just the design) would meet the Option B requirements if it were refilled with propellant somewhere in the cis-lunar vicinity?

It could happen.  SpaceX might decide that there's enough close-in business to go straight to an 8-12 person crew module, in which case Option A and Option B might be identical, and both SpaceX and NASA might be fine letting Artemis III's HLS become the Option B test flight.  On the other hand, SpaceX does love the minimum viable product, and such a crew module seems a bit maximalist for them.

One thing that might make them want to go bigger:  The airlocks.  If the egress hatch is basically at the lowest level of the payload deck, then that's where the airlocks would be.  It then makes a certain amount of sense to reduce the distance that crew would have to climb down to get into the airlocks--and climb up to get out of them.  It's a nice safety feature to make it as easy as possible to get an injured astronaut up into the main crew area for treatment.

If that's the case, then the crew module may start out with multiple decks right from the git-go, which might push SpaceX toward a bigger ECLSS to handle the full volume, and then you'd kinda get an 8-12 person system by default, which would make it easy to support 4 people for an extended period.

[DanClemmensen]

Is it unreasonably hopeful to suggest the Option A crewed lander (the actual flight article, not just the design) would meet the Option B requirements if it were refilled with propellant somewhere in the cis-lunar vicinity?

I am not a SpaceX engineer, but the Option B requirements are not a huge increment over the Option A requirements given that you are starting with a Starship derivative already. This means they might use the same design as a cost-saving measure.

Refuelling is simple if you throw enough money at it: no new hardware design is needed. Put another depot in NRHO and fill it using tankers, probably laddering through the depot in Earth orbit.

But here is the show-stopper: how do you reprovision the HLS? Each mission consumes a lot more than just LO₂ and LCH₄. You need cargo and you need consumables. You may need customized EVA suits.  Something must bring that stuff to NRHO, and you need a port that is big enough to transfer the stuff.

[JayWee]

Is it unreasonably hopeful to suggest the Option A crewed lander (the actual flight article, not just the design) would meet the Option B requirements if it were refilled with propellant somewhere in the cis-lunar vicinity?

It could happen.  SpaceX might decide that there's enough close-in business to go straight to an 8-12 person crew module, in which case Option A and Option B might be identical, and both SpaceX and NASA might be fine letting Artemis III's HLS become the Option B test flight.  On the other hand, SpaceX does love the minimum viable product, and such a crew module seems a bit maximalist for them.

...

If that's the case, then the crew module may start out with multiple decks right from the git-go, which might push SpaceX toward a bigger ECLSS to handle the full volume, and then you'd kinda get an 8-12 person system by default, which would make it easy to support 4 people for an extended period.

Don't forget dearMoon and the Tito flight. Both are planned for up to 12 people. The crew module will be similar if not identical.

[JayWee]

Is it unreasonably hopeful to suggest the Option A crewed lander (the actual flight article, not just the design) would meet the Option B requirements if it were refilled with propellant somewhere in the cis-lunar vicinity?

I am not a SpaceX engineer, but the Option B requirements are not a huge increment over the Option A requirements given that you are starting with a Starship derivative already. This means they might use the same design as a cost-saving measure.

Yeah. They were problematic for the BO HLS who essentially had to start from scratch for Opt B due to its tiny size.

[TheRadicalModerate]

Is it unreasonably hopeful to suggest the Option A crewed lander (the actual flight article, not just the design) would meet the Option B requirements if it were refilled with propellant somewhere in the cis-lunar vicinity?

It could happen.  SpaceX might decide that there's enough close-in business to go straight to an 8-12 person crew module, in which case Option A and Option B might be identical, and both SpaceX and NASA might be fine letting Artemis III's HLS become the Option B test flight.  On the other hand, SpaceX does love the minimum viable product, and such a crew module seems a bit maximalist for them.

...

If that's the case, then the crew module may start out with multiple decks right from the git-go, which might push SpaceX toward a bigger ECLSS to handle the full volume, and then you'd kinda get an 8-12 person system by default, which would make it easy to support 4 people for an extended period.

Don't forget dearMoon and the Tito flight. Both are planned for up to 12 people. The crew module will be similar if not identical.

That's what I meant by "close-in business."  But both of those are currently missions that have crewed launch and EDL.  That likely makes them Starship, as opposed to lunar Starship.

Note that LSS will likely have a docking port on the nose, while a vanilla Starship can't; that's where the header tanks are.  So they could have a fairly different crew cabin layout.  (Or maybe the same layout, but without a docking tunnel; the possibilities are endless.)

I keep waiting for SpaceX to reinstate the 7-crew D2, which would allow them to use the LSS for bigger private flights, to either cislunar or the lunar surface.  But those flights require a lot more refueling (to get back to LEO propulsively), and therefore may have too high a per-seat price.

[TheRadicalModerate]

But here is the show-stopper: how do you reprovision the HLS? Each mission consumes a lot more than just LO₂ and LCH₄. You need cargo and you need consumables. You may need customized EVA suits.  Something must bring that stuff to NRHO, and you need a port that is big enough to transfer the stuff.

That's not an Option B requirement.  You have to be able to get about a tonne of stuff through the docking tunnel, transferred either from the Gateway or the Orion, but that's it.

I think the requirements are silent on how you reprovision the ECLSS, which I assume means it's up to the provider.  I wouldn't be incredibly surprised to see the Starship QD sprout a set of LN2 and water lines.

I don't even want to think about the toilet on mission 4.

[yg1968]

Sorry, there was a typo in my reply (which I have now fixed). In your original message, you spoke of a second option B lander in parenthesis which got me confused.

These landers have yet to be assigned to a mission but presumably Option B would be part of the Artemis V mission which is scheduled for 2027. The Appendix P lander would be part of Artemis VI in 2028 (if it is ready). This assumes that Artemis IV is a Gateway only mission. I am still hoping that NASA changes its mind on that.

See the schedule for the Artemis missions at this link:
https://arstechnica.com/science/2022/06/we-got-a-leaked-look-at-nasas-future-moon-missions-and-likely-delays/

See also page 7:
https://www.nasa.gov/sites/default/files/atoms/files/fy23_nasa_budget_request_summary.pdf

So that would be:

Non-Artemis:  LSS #1, used for Option A uncrewed test.
Artemis III: LSS #2, used for Option A crewed mission.
Artemis IV: LSS #3, used for Option B initial crewed test
Artemis V: LSS #3, refueled in NRHO for first operational Option B crew mission.
Artemis VI: Some App. P vehicle.
Artemis VII: LSS #... 3?, refueled in NRHO for second operational Option B crew mission.

We have no idea how many missions per spacecraft will be feasible.  Presumably, the minimum to claim "sustainability" is 2.

I still have this feeling that dust is going to severely limit the number of missions per spacecraft until there's an architecture that can land on Earth between missions for a thorough cleaning/refurbishment.

No. It would be something like this:

Uncrewed mission:  HLS-Starship #1, used for Option A uncrewed test.
Artemis III: HLS-Starship #2, used for Option A crewed mission.
Artemis IV only goes to Gateway, so no lander for that mission.
Artemis V: HLS Starship #3, used for Option B crewed test
Uncrewed mission: App P uncrewed demo.
Artemis VI: App. P crewed demo.
Artemis VII: Recurring services (Sustaining Lunar Transport) operational mission which could be either the HLS-Starship or the App P lander.

See the chart that I posted above:
https://forum.nasaspaceflight.com/index.php?topic=56067.msg2422236#msg2422236

[DanClemmensen]

But here is the show-stopper: how do you reprovision the HLS? Each mission consumes a lot more than just LO₂ and LCH₄. You need cargo and you need consumables. You may need customized EVA suits.  Something must bring that stuff to NRHO, and you need a port that is big enough to transfer the stuff.

That's not an Option B requirement.  You have to be able to get about a tonne of stuff through the docking tunnel, transferred either from the Gateway or the Orion, but that's it.

I think the requirements are silent on how you reprovision the ECLSS, which I assume means it's up to the provider.  I wouldn't be incredibly surprised to see the Starship QD sprout a set of LN2 and water lines.

I don't even want to think about the toilet on mission 4.

I think each crew is supposed to clean the toilet in 1/6 g, just before leaving the surface.

[yg1968]

Is it unreasonably hopeful to suggest the Option A crewed lander (the actual flight article, not just the design) would meet the Option B requirements if it were refilled with propellant somewhere in the cis-lunar vicinity?

I am not a SpaceX engineer, but the Option B requirements are not a huge increment over the Option A requirements given that you are starting with a Starship derivative already. This means they might use the same design as a cost-saving measure.

Refuelling is simple if you throw enough money at it: no new hardware design is needed. Put another depot in NRHO and fill it using tankers, probably laddering through the depot in Earth orbit.

But here is the show-stopper: how do you reprovision the HLS? Each mission consumes a lot more than just LO₂ and LCH₄. You need cargo and you need consumables. You may need customized EVA suits.  Something must bring that stuff to NRHO, and you need a port that is big enough to transfer the stuff.

The EVA suits aren't required to be brought back to NRHO, they can stay on the surface:
https://forum.nasaspaceflight.com/index.php?topic=53612.msg2305334#msg2305334

[DanClemmensen]

Is it unreasonably hopeful to suggest the Option A crewed lander (the actual flight article, not just the design) would meet the Option B requirements if it were refilled with propellant somewhere in the cis-lunar vicinity?

I am not a SpaceX engineer, but the Option B requirements are not a huge increment over the Option A requirements given that you are starting with a Starship derivative already. This means they might use the same design as a cost-saving measure.

Refuelling is simple if you throw enough money at it: no new hardware design is needed. Put another depot in NRHO and fill it using tankers, probably laddering through the depot in Earth orbit.

But here is the show-stopper: how do you reprovision the HLS? Each mission consumes a lot more than just LO₂ and LCH₄. You need cargo and you need consumables. You may need customized EVA suits.  Something must bring that stuff to NRHO, and you need a port that is big enough to transfer the stuff.

The EVA suits aren't required to be brought back to NRHO, they can stay on the surface:
https://forum.nasaspaceflight.com/index.php?topic=53612.msg2305334#msg2305334

I thought the suits were custom-fitted for each crew member. The post you point to (thanks!) is about "xEVA hardware", which I would take to mean the ancillary stuff like backpacks and outerwear that is not custom-fitted.  And yes, if it can be left on the surface for reuse, it can be left in the HLS for reuse even more profitably if the upmass is supportable since the HLS might not return to the same spot on the Moon.

My post was about reprovisioning an HLS in NRHO or elsewhere in space. Reuse requires reprovisioning, so you cannot plan on having anything on board that is customized to a specific crewmember unless you have a way to convey it from Earth  and a way to transfer it to HLS.

[yg1968]

Is it unreasonably hopeful to suggest the Option A crewed lander (the actual flight article, not just the design) would meet the Option B requirements if it were refilled with propellant somewhere in the cis-lunar vicinity?

I am not a SpaceX engineer, but the Option B requirements are not a huge increment over the Option A requirements given that you are starting with a Starship derivative already. This means they might use the same design as a cost-saving measure.

Refuelling is simple if you throw enough money at it: no new hardware design is needed. Put another depot in NRHO and fill it using tankers, probably laddering through the depot in Earth orbit.

But here is the show-stopper: how do you reprovision the HLS? Each mission consumes a lot more than just LO₂ and LCH₄. You need cargo and you need consumables. You may need customized EVA suits.  Something must bring that stuff to NRHO, and you need a port that is big enough to transfer the stuff.

The EVA suits aren't required to be brought back to NRHO, they can stay on the surface:
https://forum.nasaspaceflight.com/index.php?topic=53612.msg2305334#msg2305334

I thought the suits were custom-fitted for each crew member. The post you point to (thanks!) is about "xEVA hardware", which I would take to mean the ancillary stuff like backpacks and outerwear that is not custom-fitted.  And yes, if it can be left on the surface for reuse, it can be left in the HLS for reuse even more profitably if the upmass is supportable since the HLS might not return to the same spot on the Moon.

My post was about reprovisioning an HLS in NRHO or elsewhere in space. Reuse requires reprovisioning, so you cannot plan on having anything on board that is customized to a specific crewmember unless you have a way to convey it from Earth  and a way to transfer it to HLS.

From what I recall, the spacesuits aren't customed made but they will have several body types that will fit the whole range of astronauts.

One firm requirement, however, is a flexible design that will accommodate astronauts of all sizes: The new suits must fit a woman at the fifth percentile to a man at the 95th percentile.

https://arstechnica.com/science/2022/06/nasa-announces-a-new-plan-to-buy-private-spacesuits-to-make-lunar-landing-date/

See also this link:
https://www.thewellnews.com/space/nasa-announces-companies-contracted-to-create-competing-next-gen-spacesuits/

[DanClemmensen]

From what I recall, the spacesuits aren't customed made but they will have several body types that will fit the whole range of astronauts.

One firm requirement, however, is a flexible design that will accommodate astronauts of all sizes: The new suits must fit a woman at the fifth percentile to a man at the 95th percentile.

https://arstechnica.com/science/2022/06/nasa-announces-a-new-plan-to-buy-private-spacesuits-to-make-lunar-landing-date/

So a reusable HLS would need to carry a range of suits from Earth, or there must be a way to move suits into the HLS in space (or NASA will need to select crew to match the suits in the HLS).

[yg1968]

From what I recall, the spacesuits aren't customed made but they will have several body types that will fit the whole range of astronauts.

One firm requirement, however, is a flexible design that will accommodate astronauts of all sizes: The new suits must fit a woman at the fifth percentile to a man at the 95th percentile.

https://arstechnica.com/science/2022/06/nasa-announces-a-new-plan-to-buy-private-spacesuits-to-make-lunar-landing-date/

So a reusable HLS would need to carry a range of suits from Earth, or there must be a way to move suits into the HLS in space (or NASA will need to select crew to match the suits in the HLS).

Presumably, only some spacesuit parts would be necessary but you make a good point about the need to restock the HLS if the intent is to reuse it. For spacesuits, reuse seems to be a nice to have but not a requirement. Reuse of the HLS is also not a requirement but also a nice to have in order to improve affordability. So it's really up to the providers as to how they want to reuse HLS or the spacesuits.

[DanClemmensen]

From what I recall, the spacesuits aren't customed made but they will have several body types that will fit the whole range of astronauts.

One firm requirement, however, is a flexible design that will accommodate astronauts of all sizes: The new suits must fit a woman at the fifth percentile to a man at the 95th percentile.

https://arstechnica.com/science/2022/06/nasa-announces-a-new-plan-to-buy-private-spacesuits-to-make-lunar-landing-date/

So a reusable HLS would need to carry a range of suits from Earth, or there must be a way to move suits into the HLS in space (or NASA will need to select crew to match the suits in the HLS).

Presumably, only some spacesuit parts would be necessary but you make a good point about the need to restock the HLS if the intent is to reuse it. For spacesuits, reuse seems to be a nice to have but not a requirement. Reuse of the HLS is also not a requirement but also a nice to have in order to improve affordability. So it's really up to the providers as to how they want to reuse HLS or the spacesuits.

From a cost standpoint, you can either design a cheap and disposable HLS, or you can figure out a way to cheaply reuse it. The question is: what does the requirement for "sustainability" mean?

Realistically, At a cadence of once every 18 months a disposable Starship HLS is probably more cost-effective. It's cheap to build because it leverages the SS manufacturing capacity. It's cheaper to operate because no recovery ops are needed. It might have residual value as a structure on the Moon or as scrap material on the Moon.

A reusable HLS will be at least a little bit more expensive to build. Refueling and reprovisioning will add to the mission costs, and a second permanent depot may be needed. I think cheap reusability will be hard to achieve.

[TheRadicalModerate]

Presumably, only some spacesuit parts would be necessary but you make a good point about the need to restock the HLS if the intent is to reuse it. For spacesuits, reuse seems to be a nice to have but not a requirement. Reuse of the HLS is also not a requirement but also a nice to have in order to improve affordability. So it's really up to the providers as to how they want to reuse HLS or the spacesuits.

From a cost standpoint, you can either design a cheap and disposable HLS, or you can figure out a way to cheaply reuse it. The question is: what does the requirement for "sustainability" mean?

Realistically, At a cadence of once every 18 months a disposable Starship HLS is probably more cost-effective. It's cheap to build because it leverages the SS manufacturing capacity. It's cheaper to operate because no recovery ops are needed. It might have residual value as a structure on the Moon or as scrap material on the Moon.

A reusable HLS will be at least a little bit more expensive to build. Refueling and reprovisioning will add to the mission costs, and a second permanent depot may be needed. I think cheap reusability will be hard to achieve.

At least for Starship, there's a pretty easy solution to this problem:  return it to Earth.

On the ground, it can be serviced to whatever level is required to make it good to go for the next mission.  And of course it can then be loaded with the cargo manifest needed for that mission.

Four issues:

1) TPS landing on the Moon means that if there are high-up landing thrusters, at least one of them has to poke out through the TPS.  On the other hand, if SpaceX goes with landing on the Raptors, the TPS has to survive whatever debris gets kicked up during landing.

The other TPS issue is how to make it play nice with landing legs.  If the legs poke out from under the skirt, ŕ la the high-altitude tests, this isn't a big deal.  But if they fold out from the sides, ŕ la F9, at least one of the legs will have to fold up to become an integral part of the TPS.  And the legs can't interfere with the elonerons.

2)  An EDL-capable LSS (EDLC-LSS) doesn't necessarily have to launch and land crew; crew can still be taken on and put off, either in cislunar or LEO.  And even if the EDLC-LSS eventually gets crew-certified for launch and EDL, it'll still need to service the Gateway.  But an EDLC-LSS needs the header tanks in the nose, so the docking port would have to be moved somewhere else.

I don't think it makes sense to combine the docking port with the surface access hatch, because the port needs a pressurized tunnel to the main crew module.  Maybe put the port above the hatch?  In that design, one of the surface airlocks might be able to do double duty as the bulk of the pressurized tunnel.

3) An EDLC-LSS will have thermal issues as it tries to store prop for long periods.  Solar white paint won't survive EDL, and of course the TPS is the TPS, which is a good insulator, but not for 90 days.  ISTM that SpaceX would have to commit to cryocooling to solve this problem.

4) All this extra stuff obviously increases the mass, which completely rules out being able to do LEO-NRHO-LS-NRHO, or even LEO-LS-LEO, on one tank of prop.  At the very least, there will be a refueling required in HEEO.  That's a non-trivial conops complication, requiring all the usual risk-management hand-wringing by NASA.

My guess is that this is too much work for Option B and SpaceX will hold off doing this until they have an EDLC-LSS that's also crew-certifiable for launch and EDL.


One other thing:  None of this will help the provider who wins Appendix P--unless they use Starship for part of their transit strategy.  Two possible options:

a) They use one or more CLVs to deploy their lander into NRHO, and it can stay there for however long it needs to, being refueled between missions, before needing ground servicing.  Then they contract with SpaceX for a vanilla Starship to go to NRHO, open a chomper, and let the HLS dock and secure itself for recovery through EDL.  What's the worst that could happen?  If the whole thing burns up, they're no worse off than if they had to abandon an unserviceable HLS in NRHO.

b) If you're going to the trouble to put the docking/securing hardware for a Starship return into your design, then you can also launch the thing on Starship.  Note that this doesn't commit you to using Starship for deployment if you've already gone to the trouble of working out deployment on other CLVs, but it gives you a much cheaper option, as long as Starship is healthy.

[TheRadicalModerate]

No. It would be something like this:

Uncrewed mission:  HLS-Starship #1, used for Option A uncrewed test.
Artemis III: HLS-Starship #2, used for Option A crewed mission.
Artemis IV only goes to Gateway, so no lander for that mission.
Artemis V: HLS Starship #3, used for Option B crewed test
Uncrewed mission: App P uncrewed demo.
Artemis VI: App. P crewed demo.
Artemis VII: Recurring services (Sustaining Lunar Transport) operational mission which could be either the HLS-Starship or the App P lander.

Where is the source showing that Artemis IV is Gateway-only?  I've heard this elsewhere, but I can't seem to run it down.

Note that in the leaked chart from Eric Berger, all missions after Artemis III no longer explicitly say that they have surface missions.  I've assumed that was because it was obvious.

The budget request deck that you linked indeed doesn't show a lander for Artemis IV.  However, it also doesn't show an Option B mission.  I think this is likely an oversight.  I also interpret the generic "TBD Human Lander" slot on Artemis V-VIII as implying that they're either Appendix P or SLD/SLT missions.

Note that in the Berger-leaked document, the "cadence" schedule create an Artemis III.5 mission, which is Block 1.  That has to be for a surface mission, because there's otherwise absolutely no reason for it to exist:  it can't deliver a co-manifested Gateway component, so there's no other reason for it to exist.  And if III.5 would be a surface mission, then IV seems like it also has to be, in either the baseline or content timelines.

[JayWee]

No. It would be something like this:

Uncrewed mission:  HLS-Starship #1, used for Option A uncrewed test.
Artemis III: HLS-Starship #2, used for Option A crewed mission.
Artemis IV only goes to Gateway, so no lander for that mission.
Artemis V: HLS Starship #3, used for Option B crewed test
Uncrewed mission: App P uncrewed demo.
Artemis VI: App. P crewed demo.
Artemis VII: Recurring services (Sustaining Lunar Transport) operational mission which could be either the HLS-Starship or the App P lander.

Where is the source showing that Artemis IV is Gateway-only?  I've heard this elsewhere, but I can't seem to run it down.

Note that in the leaked chart from Eric Berger, all missions after Artemis III no longer explicitly say that they have surface missions.  I've assumed that was because it was obvious.

The budget request deck that you linked indeed doesn't show a lander for Artemis IV.  However, it also doesn't show an Option B mission.  I think this is likely an oversight.  I also interpret the generic "TBD Human Lander" slot on Artemis V-VIII as implying that they're either Appendix P or SLD/SLT missions.

Note that in the Berger-leaked document, the "cadence" schedule create an Artemis III.5 mission, which is Block 1.  That has to be for a surface mission, because there's otherwise absolutely no reason for it to exist:  it can't deliver a co-manifested Gateway component, so there's no other reason for it to exist.  And if III.5 would be a surface mission, then IV seems like it also has to be, in either the baseline or content timelines.

Artemis IV is supposed to bring the iHAB to the gateway. Therefore there will be some work required to make connections, etc. I guess they don't want to give the crew another mission - to the surface.

[Paul451]

Where is the source showing that Artemis IV is Gateway-only?  I've heard this elsewhere, but I can't seem to run it down.

You linked a source in the budget request. There's never been a landing co-manifested with the iHab delivery, due (as JayWee notes) to the complexity of setting up Gateway for human use.