NASA's Artemis Program Updates and Discussion Thread 5

[VSECOTSPE]

So 2 guys on the surface for 5 days once every 2 years is an exploration plan?

Flags and footprints.

You get what you are willing to pay for.  Artemis could easily become a true exploration plan if it's given the resources.

Artemis is getting $8B+ a year.  The program doesn’t need more resources.  It needs to spend what it’s getting more wisely and on actual exploration.

[TheRadicalModerate]

I can't find an actual GDSS spec.  I'm assuming that it's a superset of IDSS, and has the ability to accommodate an IDSS implementation.  It would obviously be missing all the fancy fluid transfer capabilities.  But my guess is that SpaceX has different plans for how fluids get transferred to an LSS.

It doesn't appear to be public yet.  I assume they plan on releasing it as part of the www.internationaldeepspacestandards.com (like is done for the www.internationaldockingstandard.com).  That one, Rev F, shows all the locations for the umbilicals and fluids for GDSS, but what isn't shown are details about the umblicals (which are different).  So, as far as I'm aware, IDSS and GDSS systems can make a pressure seal, but not transfer power and data.  I was under the impression that the GDSS fluid transfer specification was most critical to re-fueling the PPE?

I assume that GDSS does not support cryogenic transfers?

If only the Dragon XL needs to implement GDSS fluid transfer, I imagine the wiring modifications are pretty easy.  (BTW, why do you think they changed the power and data interfaces?  That kinda seems like somebody wasn't thinking ahead about the fluids if they had to relocate electrical connectors to make it work.  Surely this must have come up while hashing out IDSS.)

[TheRadicalModerate]

Use a DragonXL for the tug. This does require yet another FH mission in addition to the FH used for the I-Hab. Dragon XL must already be able to do autonomous RPOD and must already have an active IDSS axial port.

For me, using any autonomous tug to dock the tug+I-Hab to PPE+HALO just seems magical because the thrusters are so far away from the port being docked, but I'm not a rocket scientist and therefore my visualization of this maneuver is probably faulty.

DXL or Cygnus, either one will have to lose its pressure vessel and make some software changes.  As I said, I suspect that NorGrum cares quite a bit about making a naked Cygnus bus, if for no other reason than they had to bid one for SLD refueling.  Meanwhile SpaceX is probably "meh" about a naked Dragon bus.

And yes, rotation tensors for an RCS system that's so far from the docking system do indeed seem magical.  But the Orion people have obviously figured them out, so somebody else can, too.

[Zed_Noir]

Will point out that eventually SpaceX needs the dual active and passive docking capabilities for their vehicles.

If the Artemis program stumbles for too long and the LSS landers along with the supporting tankers are ready. SpaceX might consider mounting a private Option B LSS crewed landing test mission. Of course this would be the second LSS landing on the Moon after the uncrewed LSS test landing around the end of 2024.

While such a Lunar test mission might be expensive. It will be much cheaper doing a LEO-LS-LEO mission profile, skipping the NRHO part along with not using the SLS and the Orion.

You can't do LEO-LS-LEO without refueling somewhere in cislunar space.  If you do that pre-descent, it's really expensive and complex.  If you do it post-ascent, you run the risk of stranding the crew if the refueling fails.  I think that risk rapidly diminishes with refueling experience, but it's not the sort of thing you want to do on your second lunar mission without a Plan B.

SpaceX will likely have plenty of prototype and early production Starship tankers and Starship Depots to be able to expended one of them as a Mega "Drop Tank" for a LEO-LS-LEO mission profile.

Staged from LEO with the "Drop Tank" docked to the LSS as combine stack for Earth departure after both have been fill up from either tankers from Earth or orbital depots.

The LSS transfer propellants from the "Drop Tank" prior to attempting a landing on the Lunar surface while they are still docked together. Then jettisoning the "Drop Tank".

This is an one off crewed LSS test mission proposal after all with on hand hardware while waiting for the next SLS/Orion stack to show up.


Add't: Presumably there will some sort of viable Lunar surface exclusion EVA suit available for the Moon walkers for this mission. Kinda pointless if you couldn't walk on the regolith.

[yg1968]

According to the FY24 NASA Budget request, Artemis III is now December 2025 and Artemis IV is now September 2028 <snip>

Almost 3 years between flights!
Further proof that Artemis is NOT a true exploration plan.

I am not sure that it's proof of that. Artemis IV has a lot of new elements to it including the EUS and ML2. It seems likely that Artemis III will slip into 2026. As Eric Berger mentioned before, it might be better to let Artemis III slip into 2026 to avoid a 3 year gap.

Sure it is. Even with a slip to 2026 it's still a 2 year gap.
So 2 guys on the surface for 5 days once every 2 years is an exploration plan?
I don't think so.

The cadence of missions doesn't determine if a program is an exploration program. We have missions to Mars every 2 years and we still consider them exploration missions. There will be one mission per year after Artemis IV (Artemis I to IV are essentially demo/non-operational missions where each mission has important new elements to it). If you include CLPS, there will be more than one lunar mission per year. Furthermore, the LTV will be exploring the Moon when humans aren't exploring it. So there will be full time exploration of the Moon under Artemis.

[yg1968]

So 2 guys on the surface for 5 days once every 2 years is an exploration plan?

Flags and footprints.

You get what you are willing to pay for.  Artemis could easily become a true exploration plan if it's given the resources.

Artemis is getting $8B+ a year.  The program doesn’t need more resources.  It needs to spend what it’s getting more wisely and on actual exploration.

It's not flag and footprints since the objective is to permanently return to the Moon. Given the budgets constraints, the missions at first are only for a few days but the days spent on the Moon will increase. Each mission is progressively more difficult. The main difference with Apollo is that there shouldn't be an end to Artemis. That is a big difference.

[Robotbeat]

If those once-in-two-years missions to Mars are short stay, then yeah that doesn’t seem like an exploration program. If they are long stay or continuous inhabitation, it does.

[DanClemmensen]

So 2 guys on the surface for 5 days once every 2 years is an exploration plan?

Flags and footprints.

You get what you are willing to pay for.  Artemis could easily become a true exploration plan if it's given the resources.

Artemis is getting $8B+ a year.  The program doesn’t need more resources.  It needs to spend what it’s getting more wisely and on actual exploration.

It's not flag and footprints since the objective is to permanently return to the Moon. Given the budgets constraints, the missions at first are only for a few days but the days spent on the Moon will increase. Each mission is progressively more difficult. The main difference with Apollo is that there shouldn't be an end to Artemis. That is a big difference.

"The road to Hell is paved with good intentions." Apollo was terminated earlier than originally planned, and NASA certainly advertised it as the beginning of a continuing program. We won't know if Artemis is just flags and footprints until at one actual exploration expedition occurs. For me that's four or more crew for a month or more at a bare minimum. I do not think Artemis can proceed beyond flags and footprints until SLS and Orion are retired.

[jarmumd]

...

I assume that GDSS does not support cryogenic transfers?

If only the Dragon XL needs to implement GDSS fluid transfer, I imagine the wiring modifications are pretty easy.  (BTW, why do you think they changed the power and data interfaces?  That kinda seems like somebody wasn't thinking ahead about the fluids if they had to relocate electrical connectors to make it work.  Surely this must have come up while hashing out IDSS.)

It's a bit more generic when it comes to the fluid umbilicals.  I think it can support cryo, but the scale is much smaller than say refueling starship.  I think the main purpose is to provide a way to transfer xenon propellant to refuel the PPE?  I think they changed the interface to support gateway and Orion using Time Triggered Ethernet (TTE).  And because anything docking to gateway would need to go through some amount of new certification anyways, now would be a good time to change to a new (better??) standard.  And they didn't relocate the electrical connectors, they are the same connectors even, in the same place.  But the individual electrical connections do not mate.

For a different thread, but this IDSS vs GDSS creates a bit of a problem for which spec to use for commercial space stations.  IDSS would allow for Dragon and CST-100, but GDSS might be more capable?

[yg1968]

So 2 guys on the surface for 5 days once every 2 years is an exploration plan?

Flags and footprints.

You get what you are willing to pay for.  Artemis could easily become a true exploration plan if it's given the resources.

Artemis is getting $8B+ a year.  The program doesn’t need more resources.  It needs to spend what it’s getting more wisely and on actual exploration.

It's not flag and footprints since the objective is to permanently return to the Moon. Given the budgets constraints, the missions at first are only for a few days but the days spent on the Moon will increase. Each mission is progressively more difficult. The main difference with Apollo is that there shouldn't be an end to Artemis. That is a big difference.

"The road to Hell is paved with good intentions." Apollo was terminated earlier than originally planned, and NASA certainly advertised it as the beginning of a continuing program. We won't know if Artemis is just flags and footprints until at one actual exploration expedition occurs. For me that's four or more crew for a month or more at a bare minimum. I do not think Artemis can proceed beyond flags and footprints until SLS and Orion are retired.

Apollo was supposed to end with Apollo 20, it had an end. Artemis does not.

[DanClemmensen]

I can't find an actual GDSS spec.  I'm assuming that it's a superset of IDSS, and has the ability to accommodate an IDSS implementation.  It would obviously be missing all the fancy fluid transfer capabilities.  But my guess is that SpaceX has different plans for how fluids get transferred to an LSS.

It doesn't appear to be public yet.  I assume they plan on releasing it as part of the www.internationaldeepspacestandards.com (like is done for the www.internationaldockingstandard.com).  That one, Rev F, shows all the locations for the umbilicals and fluids for GDSS, but what isn't shown are details about the umblicals (which are different).  So, as far as I'm aware, IDSS and GDSS systems can make a pressure seal, but not transfer power and data.  I was under the impression that the GDSS fluid transfer specification was most critical to re-fueling the PPE?

I assume that GDSS does not support cryogenic transfers?

If only the Dragon XL needs to implement GDSS fluid transfer, I imagine the wiring modifications are pretty easy.  (BTW, why do you think they changed the power and data interfaces?  That kinda seems like somebody wasn't thinking ahead about the fluids if they had to relocate electrical connectors to make it work.  Surely this must have come up while hashing out IDSS.)

NOTE: all of this is from analysis of stuff in Wikipedia and not from any inside info or actual analysis of source documents.

Dragon XL does not dock directly to each Gateway module, so if other modules need fluids I guess each of the intra-Gateway ports will need to conduct fluids.

Apparently, Xenon for PPE will be transferred from ESPRIT, not Dragon XL, and ESPRIT will be replaced as needed at long intervals. But ESPRIT is docked to HALO, not directly to PPE, so the ESPRIT-HALO and HALO-PPE ports must be able to handle Xenon.

[clongton]

The cadence of missions doesn't determine if a program is an exploration program. We have missions to Mars every 2 years and we still consider them exploration missions. There will be one mission per year after Artemis IV (Artemis I to IV are essentially demo/non-operational missions where each mission has important new elements to it). If you include CLIPS, there will be more than one lunar mission per year. Furthermore, the LTV will be exploring the Moon when humans aren't exploring it. So there will be full time exploration of the Moon under Artemis.

The most important element of any lunar exploration program is time on the surface, specifically to locate reasonably exploitable resources for future exploitation and to identify suitable locations for ISRU facilities for resource extraction equipment and facilities to process those resources into usable products. If we're not going there for this purpose then what is the sense of going there at all? Just so we can say we did? Been there, done that. The Artemis mission cadence is dooming it in this regard to be a miserable failure, with or without CLIPS. True exploration requires boots on the ground for multiple months at a time during any calendar year. Anything short of that is a waste. Supposedly we are going back to the moon "this time to stay". Really? Not if we are depending on this program to facilitate that. In this regard, the way this Artemis program is structured, it is not a true exploration program. It's a feel good, look at me, must take picture effort. We are capable of SO much better.

[whitelancer64]

I can't find an actual GDSS spec.  I'm assuming that it's a superset of IDSS, and has the ability to accommodate an IDSS implementation.  It would obviously be missing all the fancy fluid transfer capabilities.  But my guess is that SpaceX has different plans for how fluids get transferred to an LSS.

It doesn't appear to be public yet.  I assume they plan on releasing it as part of the www.internationaldeepspacestandards.com (like is done for the www.internationaldockingstandard.com).  That one, Rev F, shows all the locations for the umbilicals and fluids for GDSS, but what isn't shown are details about the umblicals (which are different).  So, as far as I'm aware, IDSS and GDSS systems can make a pressure seal, but not transfer power and data.  I was under the impression that the GDSS fluid transfer specification was most critical to re-fueling the PPE?

I assume that GDSS does not support cryogenic transfers?

If only the Dragon XL needs to implement GDSS fluid transfer, I imagine the wiring modifications are pretty easy.  (BTW, why do you think they changed the power and data interfaces?  That kinda seems like somebody wasn't thinking ahead about the fluids if they had to relocate electrical connectors to make it work.  Surely this must have come up while hashing out IDSS.)

NOTE: all of this is from analysis of stuff in Wikipedia and not from any inside info or actual analysis of source documents.

Dragon XL does not dock directly to each Gateway module, so if other modules need fluids I guess each of the intra-Gateway ports will need to conduct fluids.

Apparently, Xenon for PPE will be transferred from ESPRIT, not Dragon XL, and ESPRIT will be replaced as needed at long intervals. But ESPRIT is docked to HALO, not directly to PPE, so the ESPRIT-HALO and HALO-PPE ports must be able to handle Xenon.

No, ESPIRIT is not made to be replaced, it can be refueled. Visiting Vehicles can transfer Xenon / MON / MMH to ESPIRIT or through it directly to the PPE tanks.

[whitelancer64]

I can't find an actual GDSS spec.  I'm assuming that it's a superset of IDSS, and has the ability to accommodate an IDSS implementation.  It would obviously be missing all the fancy fluid transfer capabilities.  But my guess is that SpaceX has different plans for how fluids get transferred to an LSS.

It doesn't appear to be public yet.  I assume they plan on releasing it as part of the www.internationaldeepspacestandards.com (like is done for the www.internationaldockingstandard.com).  That one, Rev F, shows all the locations for the umbilicals and fluids for GDSS, but what isn't shown are details about the umblicals (which are different).  So, as far as I'm aware, IDSS and GDSS systems can make a pressure seal, but not transfer power and data.  I was under the impression that the GDSS fluid transfer specification was most critical to re-fueling the PPE?

I assume that GDSS does not support cryogenic transfers?

If only the Dragon XL needs to implement GDSS fluid transfer, I imagine the wiring modifications are pretty easy.  (BTW, why do you think they changed the power and data interfaces?  That kinda seems like somebody wasn't thinking ahead about the fluids if they had to relocate electrical connectors to make it work.  Surely this must have come up while hashing out IDSS.)

The IDSS reserves areas for fluid and other connections, as seen on page 56 of the PDF, page 3-43 of the document.

https://www.internationaldockingstandard.com/download/IDSS_IDD_Revision_F.pdf

[DanClemmensen]

I can't find an actual GDSS spec.  I'm assuming that it's a superset of IDSS, and has the ability to accommodate an IDSS implementation.  It would obviously be missing all the fancy fluid transfer capabilities.  But my guess is that SpaceX has different plans for how fluids get transferred to an LSS.

It doesn't appear to be public yet.  I assume they plan on releasing it as part of the www.internationaldeepspacestandards.com (like is done for the www.internationaldockingstandard.com).  That one, Rev F, shows all the locations for the umbilicals and fluids for GDSS, but what isn't shown are details about the umblicals (which are different).  So, as far as I'm aware, IDSS and GDSS systems can make a pressure seal, but not transfer power and data.  I was under the impression that the GDSS fluid transfer specification was most critical to re-fueling the PPE?

I assume that GDSS does not support cryogenic transfers?

If only the Dragon XL needs to implement GDSS fluid transfer, I imagine the wiring modifications are pretty easy.  (BTW, why do you think they changed the power and data interfaces?  That kinda seems like somebody wasn't thinking ahead about the fluids if they had to relocate electrical connectors to make it work.  Surely this must have come up while hashing out IDSS.)

NOTE: all of this is from analysis of stuff in Wikipedia and not from any inside info or actual analysis of source documents.

Dragon XL does not dock directly to each Gateway module, so if other modules need fluids I guess each of the intra-Gateway ports will need to conduct fluids.

Apparently, Xenon for PPE will be transferred from ESPRIT, not Dragon XL, and ESPRIT will be replaced as needed at long intervals. But ESPRIT is docked to HALO, not directly to PPE, so the ESPRIT-HALO and HALO-PPE ports must be able to handle Xenon.

No, ESPIRIT is not made to be replaced, it can be refueled. Visiting Vehicles can transfer Xenon / MON / MMH to ESPIRIT or through it directly to the PPE tanks.

Sorry, my bad. I assumed from its name (ESPRIT Refueling Module) that the ERM brought in the fuel. Apparently, it is actually the fuel storage and transfer module. Xenon will be transferred to ERM from Dragon XL.

[whitelancer64]

I can't find an actual GDSS spec.  I'm assuming that it's a superset of IDSS, and has the ability to accommodate an IDSS implementation.  It would obviously be missing all the fancy fluid transfer capabilities.  But my guess is that SpaceX has different plans for how fluids get transferred to an LSS.

It doesn't appear to be public yet.  I assume they plan on releasing it as part of the www.internationaldeepspacestandards.com (like is done for the www.internationaldockingstandard.com).  That one, Rev F, shows all the locations for the umbilicals and fluids for GDSS, but what isn't shown are details about the umblicals (which are different).  So, as far as I'm aware, IDSS and GDSS systems can make a pressure seal, but not transfer power and data.  I was under the impression that the GDSS fluid transfer specification was most critical to re-fueling the PPE?

I assume that GDSS does not support cryogenic transfers?

If only the Dragon XL needs to implement GDSS fluid transfer, I imagine the wiring modifications are pretty easy.  (BTW, why do you think they changed the power and data interfaces?  That kinda seems like somebody wasn't thinking ahead about the fluids if they had to relocate electrical connectors to make it work.  Surely this must have come up while hashing out IDSS.)

NOTE: all of this is from analysis of stuff in Wikipedia and not from any inside info or actual analysis of source documents.

Dragon XL does not dock directly to each Gateway module, so if other modules need fluids I guess each of the intra-Gateway ports will need to conduct fluids.

Apparently, Xenon for PPE will be transferred from ESPRIT, not Dragon XL, and ESPRIT will be replaced as needed at long intervals. But ESPRIT is docked to HALO, not directly to PPE, so the ESPRIT-HALO and HALO-PPE ports must be able to handle Xenon.

No, ESPIRIT is not made to be replaced, it can be refueled. Visiting Vehicles can transfer Xenon / MON / MMH to ESPIRIT or through it directly to the PPE tanks.

Attached document, "JOINT DEVELOPMENT TESTING OF THE INTEGRATED GATEWAY-ESPRIT BIPROPELLANT REFUELLING SYSTEM" with screenshots from it, is from May 2022

[TheRadicalModerate]

...

I assume that GDSS does not support cryogenic transfers?

If only the Dragon XL needs to implement GDSS fluid transfer, I imagine the wiring modifications are pretty easy.  (BTW, why do you think they changed the power and data interfaces?  That kinda seems like somebody wasn't thinking ahead about the fluids if they had to relocate electrical connectors to make it work.  Surely this must have come up while hashing out IDSS.)

It's a bit more generic when it comes to the fluid umbilicals.  I think it can support cryo, but the scale is much smaller than say refueling starship.  I think the main purpose is to provide a way to transfer xenon propellant to refuel the PPE?  I think they changed the interface to support gateway and Orion using Time Triggered Ethernet (TTE).  And because anything docking to gateway would need to go through some amount of new certification anyways, now would be a good time to change to a new (better??) standard.  And they didn't relocate the electrical connectors, they are the same connectors even, in the same place.  But the individual electrical connections do not mate.

For a different thread, but this IDSS vs GDSS creates a bit of a problem for which spec to use for commercial space stations.  IDSS would allow for Dragon and CST-100, but GDSS might be more capable?

The obvious application for cryo fluid transfer would be for refueling of one of the SLD/SLT stacks, allowing it to be refueled while docked tot he Gateway.  That would avoid having to:

1) Ascend.
2) Dock at Gateway to offload crew.
3) Loiter for a long time.
4) Undock from Gateway and stand off.
5) Dock with a tanker and transfer prop.
6) Undock from tanker and do yet another RPOD with the Gateway.

Replacing steps 4-6 with a tanker that could flow methalox or hydrolox through the Gateway infrastructure would take a lot of risk out of the system.

It does kinda beg the question of whether NASA is sweating this more elaborate conops for LSS.  It would be a pretty big plumbing change to get LSS to make nice with a Gateway-mediated system and still be able to play with Starship depots and tankers.


I didn't know about TTE.  That's probably something that would be handy to have as your visiting widget transitioned from being its own flight-critical network to part of the Gateway's flight-critical network, and would allow things like coopting a visitor's RCS systems for station- and attitude-keeping purposes without having to invent an elaborate protocol to get the visitor's avionics to act as a proxy for the Gateway's GN&C system.

The annoying thing about this is that it assumes that the set of ISS-bound spacecraft and Gateway-bound spacecraft is disjoint, which shouldn't have to be true.  However, given that ISS is getting long in the tooth and Gateway's schedule is gliding frictionlessly to the right, they're probably temporally disjoint anyway.  Might be a good time to cut over.

[Paul451]

For me that's four or more crew for a month or more at a bare minimum. I do not think Artemis can proceed beyond flags and footprints until SLS and Orion are retired.

Apollo was supposed to end with Apollo 20, it had an end. Artemis does not.

Apollo was meant to continue with the Apollo Applications program. (Of which only Skylab survived.)

There will be one mission per year after Artemis IV

No. NASA would like one mission per year, but it isn't funded, the necessary precursor development isn't being funded. And there's no capability to do so with SLS/Orion without that new development. It's the "Apollo Applications" of Artemis. Wishful thinking.

[yg1968]

No. NASA would like one mission per year, but it isn't funded, the necessary precursor development isn't being funded. And there's no capability to do so with SLS/Orion without that new development. It's the "Apollo Applications" of Artemis. Wishful thinking.

Funding is a year to year process, so obviously it isn't funded yet. There is been no indication that an increase in funding would be necessary for the operations missions (Artemis V and later missions). What is your source for saying this?

Here is what the FY24 Budget says on this:

The FY 2024 President’s Budget Request manifest supports an Artemis II mission in 2024, Artemis III mission in 2025, Artemis IV mission in 2028, and Artemis V mission in 2029 with subsequent flights on a yearly basis.

https://www.nasa.gov/sites/default/files/atoms/files/nasa_fy_2024_cj_v2.pdf

[yg1968]

Apollo was meant to continue with the Apollo Applications program. (Of which only Skylab survived.)

These weren't lunar missions. https://www.wired.com/2012/08/before-the-fire/