Author Topic: OIG report: NASA transitioning SLS to commercial contract  (Read 40470 times)

Offline pochimax

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Re: OIG report: NASA transitioning SLS to commercial contract
« Reply #40 on: 10/16/2023 06:41 pm »
Which talks about commercial alternatives to SLS. Since Orion is the only payload, it’s kind of important.
And as the report points out (albeit a bit nuanced), Orion is not the only solution if SLS is removed from the equation. Which begs the question: Why would other solutions have to cater to Orion? Simple answer: they don't. SLS and Orion are tied at the hip; they live and die together.

In reality, it is quite likely that NASA will find itself in the future with a problem to be solved but that would be easily solved: a commercial alternative (modified Starship) available to launch Orion ships, in turn already manufactured and paid for, and which could be cheaper than spending 2.5 billion on an SLS to launch them. And at the same time much more economical than building new replacement ships for Orion ships that would be completed or almost completed or in the recycling process.

Offline pochimax

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Re: OIG report: NASA transitioning SLS to commercial contract
« Reply #41 on: 10/16/2023 06:44 pm »
The best scenario to hope for is to have redundancy for SLS and Orion through a commercial option. I don't think that Congress is going to kill SLS and Orion in the short term especially if a commercial replacement isn't yet available.
This will depend on the definition of "available". One scheme proposes a second instance of HLS as an OTV to ferry crew from a Crew Dragon in LEO to NRHO. it uses no hardware that is not already needed for Artemis III. Is it "available"? How does its availability differ from EUS, Gateway, or an Orion with an NDS port?

If we follow the OIG and NASA report, it is not considered that there is currently any commercial alternative available. They estimate that there could be one within a period of 3 to 5 years.

Quote
As to Artemis III being "advanced in its construction": sunk costs are sunk. If a viable alternative can be delivered in the same timeframe as the longest-lead Artemis III deliverable, then the existence of this hardware is irrelevant.

So, according to OIG and NASA, there is no alternative currently nor will there be in at least 3 years. That is why it is physically impossible to find any alternative to Artemis III, since by the time the alternative is available, the rocket will be on the pad or launched.
« Last Edit: 10/16/2023 06:48 pm by pochimax »

Offline DanClemmensen

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Re: OIG report: NASA transitioning SLS to commercial contract
« Reply #42 on: 10/16/2023 07:47 pm »
My preferred solution as a Starship enthusiast is to replace Gateway entirely, using a custom Starship. It's likely to be cheaper than an individual Gateway module and its LV, and this is certainly true if the module launches on SLS/Orion.

very difficult to cancel or modify the gateway for a Starship. NASA would have to pay Europe and Japan for everything invested so far. I don't think ESA or JAXA could be convinced of the change. It's a very, very unrealistic scenario.

So, ...actually the problem is simplified and reduced to launching the two or three international modules of the Gateway with the SLS or with a commercial alternative. Any other variant is not a plausible scenario.
The partners agreed to exchange seats to Gateway for gateway hardware, and their sunk costs are sunk. In a rational world, NASA would offer to replace these few seats to Gateway with quite a few more seats to gateway plus seats to the Lunar surface. The partners would agree to abandon the in-progress Gateway components and begin contributing to fitting out the Starship Gateway. I doubt this can actually happen because of institutional inertia.

Offline DanClemmensen

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Re: OIG report: NASA transitioning SLS to commercial contract
« Reply #43 on: 10/16/2023 07:50 pm »
The best scenario to hope for is to have redundancy for SLS and Orion through a commercial option. I don't think that Congress is going to kill SLS and Orion in the short term especially if a commercial replacement isn't yet available.
This will depend on the definition of "available". One scheme proposes a second instance of HLS as an OTV to ferry crew from a Crew Dragon in LEO to NRHO. it uses no hardware that is not already needed for Artemis III. Is it "available"? How does its availability differ from EUS, Gateway, or an Orion with an NDS port?

If we follow the OIG and NASA report, it is not considered that there is currently any commercial alternative available. They estimate that there could be one within a period of 3 to 5 years.

Quote
As to Artemis III being "advanced in its construction": sunk costs are sunk. If a viable alternative can be delivered in the same timeframe as the longest-lead Artemis III deliverable, then the existence of this hardware is irrelevant.

So, according to OIG and NASA, there is no alternative currently nor will there be in at least 3 years. That is why it is physically impossible to find any alternative to Artemis III, since by the time the alternative is available, the rocket will be on the pad or launched.
It is not possible to replace SLS to launch Orion without substantial new hardware development and crew qualification of the launcher. However, it is probably feasible to replace SLS/Orion using hardware that is already in development for Artemis III. Replacement of SLS/Orion was not addressed in the OIG report.

Offline yg1968

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Re: OIG report: NASA transitioning SLS to commercial contract
« Reply #44 on: 10/17/2023 12:38 am »
Can you expand on SLS and Orion being joined at the hip? Straight up question. No snark.

Only launch manifest for SLS in the foreseeable future is Orion as part of Artemis. Only LV manifested to launch on SLS is Orion. That is very unlikely to change. SLS is simply too expensive for other missions (one reason why Europa Clipper moved to FH). Orion is tied to Artemis, which is tied to SLS. Could Orion be untied from SLS? Maybe--a number of other threads discuss options. But the cost for an Orion mission is still very steep--regardless of LV--so once you take one out of the equation, think the other will follow.

edit: p.s. OIG report hints at that with the statement "NASA’s SLS single-use rocket". Single use = Orion/Artemis.

SLS will also be used for Gateway modules: IHab and Esprit (and perhaps the Airlock). However, Orion will also be part of these missions.

Only if NASA have the SLS Block 1B available. More likely the Falcon Heavy will launch the iHab, Esplit and airlock modules to NRHO due to cost and scheduling. Since the SLS Block 1B be on schedule is extremely unlikely, IMO.

Kinda of silly waiting for a $4.5B+ SLS Block 1B/Orion stack (according to NASA IG) when you can booked several Falcon Heavies for less than $200M each immediately. So @joek is likely correct that the Orion will be the only payload for the SLS. Which NASA is unlikely to get the Block 1B version operational any time soon.

What is the point of launching IHab, Esprit and the Airlock with FH if you can't get to them with Orion? Woods170 had mentioned that NASA was considering using FH for other Gateway modules but I don't think that anything has been announced on that front. 
« Last Edit: 10/17/2023 12:38 am by yg1968 »

Offline DanClemmensen

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Re: OIG report: NASA transitioning SLS to commercial contract
« Reply #45 on: 10/17/2023 01:19 am »
Can you expand on SLS and Orion being joined at the hip? Straight up question. No snark.

Only launch manifest for SLS in the foreseeable future is Orion as part of Artemis. Only LV manifested to launch on SLS is Orion. That is very unlikely to change. SLS is simply too expensive for other missions (one reason why Europa Clipper moved to FH). Orion is tied to Artemis, which is tied to SLS. Could Orion be untied from SLS? Maybe--a number of other threads discuss options. But the cost for an Orion mission is still very steep--regardless of LV--so once you take one out of the equation, think the other will follow.

edit: p.s. OIG report hints at that with the statement "NASA’s SLS single-use rocket". Single use = Orion/Artemis.

SLS will also be used for Gateway modules: IHab and Esprit (and perhaps the Airlock). However, Orion will also be part of these missions.

Only if NASA have the SLS Block 1B available. More likely the Falcon Heavy will launch the iHab, Esplit and airlock modules to NRHO due to cost and scheduling. Since the SLS Block 1B be on schedule is extremely unlikely, IMO.

Kinda of silly waiting for a $4.5B+ SLS Block 1B/Orion stack (according to NASA IG) when you can booked several Falcon Heavies for less than $200M each immediately. So @joek is likely correct that the Orion will be the only payload for the SLS. Which NASA is unlikely to get the Block 1B version operational any time soon.

What is the point of launching IHab, Esprit and the Airlock with FH if you can't get to them with Orion? Woods170 had mentioned that NASA was considering using FH for other Gateway modules but I don't think that anything has been announced on that front.
These modules are not powered. They cannot get from TLI to NRHO without a tug, and they cannot RPOD to Gateway without a tug. Orion serves as the tug.  To boost a module using FH,You will need to design some sort of OTV that can launch with the module and can perform these functions. Yuck.

Offline Asteroza

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Re: OIG report: NASA transitioning SLS to commercial contract
« Reply #46 on: 10/17/2023 02:05 am »
Can you expand on SLS and Orion being joined at the hip? Straight up question. No snark.

Only launch manifest for SLS in the foreseeable future is Orion as part of Artemis. Only LV manifested to launch on SLS is Orion. That is very unlikely to change. SLS is simply too expensive for other missions (one reason why Europa Clipper moved to FH). Orion is tied to Artemis, which is tied to SLS. Could Orion be untied from SLS? Maybe--a number of other threads discuss options. But the cost for an Orion mission is still very steep--regardless of LV--so once you take one out of the equation, think the other will follow.

edit: p.s. OIG report hints at that with the statement "NASA’s SLS single-use rocket". Single use = Orion/Artemis.

SLS will also be used for Gateway modules: IHab and Esprit (and perhaps the Airlock). However, Orion will also be part of these missions.

Only if NASA have the SLS Block 1B available. More likely the Falcon Heavy will launch the iHab, Esplit and airlock modules to NRHO due to cost and scheduling. Since the SLS Block 1B be on schedule is extremely unlikely, IMO.

Kinda of silly waiting for a $4.5B+ SLS Block 1B/Orion stack (according to NASA IG) when you can booked several Falcon Heavies for less than $200M each immediately. So @joek is likely correct that the Orion will be the only payload for the SLS. Which NASA is unlikely to get the Block 1B version operational any time soon.

What is the point of launching IHab, Esprit and the Airlock with FH if you can't get to them with Orion? Woods170 had mentioned that NASA was considering using FH for other Gateway modules but I don't think that anything has been announced on that front.
These modules are not powered. They cannot get from TLI to NRHO without a tug, and they cannot RPOD to Gateway without a tug. Orion serves as the tug.  To boost a module using FH,You will need to design some sort of OTV that can launch with the module and can perform these functions. Yuck.

You could stick yet another PPE to those modules to get them there. Gateway would be swimming in PPE's though, which might not be a bad thing per se...

Offline DanClemmensen

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Re: OIG report: NASA transitioning SLS to commercial contract
« Reply #47 on: 10/17/2023 02:08 am »
Can you expand on SLS and Orion being joined at the hip? Straight up question. No snark.

Only launch manifest for SLS in the foreseeable future is Orion as part of Artemis. Only LV manifested to launch on SLS is Orion. That is very unlikely to change. SLS is simply too expensive for other missions (one reason why Europa Clipper moved to FH). Orion is tied to Artemis, which is tied to SLS. Could Orion be untied from SLS? Maybe--a number of other threads discuss options. But the cost for an Orion mission is still very steep--regardless of LV--so once you take one out of the equation, think the other will follow.

edit: p.s. OIG report hints at that with the statement "NASA’s SLS single-use rocket". Single use = Orion/Artemis.

SLS will also be used for Gateway modules: IHab and Esprit (and perhaps the Airlock). However, Orion will also be part of these missions.

Only if NASA have the SLS Block 1B available. More likely the Falcon Heavy will launch the iHab, Esplit and airlock modules to NRHO due to cost and scheduling. Since the SLS Block 1B be on schedule is extremely unlikely, IMO.

Kinda of silly waiting for a $4.5B+ SLS Block 1B/Orion stack (according to NASA IG) when you can booked several Falcon Heavies for less than $200M each immediately. So @joek is likely correct that the Orion will be the only payload for the SLS. Which NASA is unlikely to get the Block 1B version operational any time soon.

What is the point of launching IHab, Esprit and the Airlock with FH if you can't get to them with Orion? Woods170 had mentioned that NASA was considering using FH for other Gateway modules but I don't think that anything has been announced on that front.
These modules are not powered. They cannot get from TLI to NRHO without a tug, and they cannot RPOD to Gateway without a tug. Orion serves as the tug.  To boost a module using FH,You will need to design some sort of OTV that can launch with the module and can perform these functions. Yuck.

You could stick yet another PPE to those modules to get them there. Gateway would be swimming in PPE's though, which might not be a bad thing per se...
A PPE could get a module to NRHO. I don't think is has the right thrusters to RPOD, though.

Online woods170

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Re: OIG report: NASA transitioning SLS to commercial contract
« Reply #48 on: 10/17/2023 08:15 am »
What is the point of launching IHab, Esprit and the Airlock with FH if you can't get to them with Orion? Woods170 had mentioned that NASA was considering using FH for other Gateway modules but I don't think that anything has been announced on that front. 

Still actively being worked on by groups at NASA. The idea is to use NG's Cygnus-based tug vehicles to deliver the modules to Gateway. Remember: before HALO was merged with PPE, it was supposed to be delivered as a separate module, where a modified service section of a Cygnus CRS vehicle would act as the tug. Which would make perfect sense given that the HALO pressure hull is directly derived from a Cygnus pressure hull. The major difference between a standard Cygnus and the originally conceived HALO, was that the service section (the tug) could detach itself from the pressure module.

When NASA decided to merge PPE and HALO into one integrated vehicle, they didn't do away with the idea of having a modified Cygnus service section as a tug.
« Last Edit: 10/18/2023 01:58 pm by woods170 »

Offline Zed_Noir

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Re: OIG report: NASA transitioning SLS to commercial contract
« Reply #49 on: 10/17/2023 08:25 am »
Can you expand on SLS and Orion being joined at the hip? Straight up question. No snark.

Only launch manifest for SLS in the foreseeable future is Orion as part of Artemis. Only LV manifested to launch on SLS is Orion. That is very unlikely to change. SLS is simply too expensive for other missions (one reason why Europa Clipper moved to FH). Orion is tied to Artemis, which is tied to SLS. Could Orion be untied from SLS? Maybe--a number of other threads discuss options. But the cost for an Orion mission is still very steep--regardless of LV--so once you take one out of the equation, think the other will follow.

edit: p.s. OIG report hints at that with the statement "NASA’s SLS single-use rocket". Single use = Orion/Artemis.

SLS will also be used for Gateway modules: IHab and Esprit (and perhaps the Airlock). However, Orion will also be part of these missions.

Only if NASA have the SLS Block 1B available. More likely the Falcon Heavy will launch the iHab, Esplit and airlock modules to NRHO due to cost and scheduling. Since the SLS Block 1B be on schedule is extremely unlikely, IMO.

Kinda of silly waiting for a $4.5B+ SLS Block 1B/Orion stack (according to NASA IG) when you can booked several Falcon Heavies for less than $200M each immediately. So @joek is likely correct that the Orion will be the only payload for the SLS. Which NASA is unlikely to get the Block 1B version operational any time soon.

What is the point of launching IHab, Esprit and the Airlock with FH if you can't get to them with Orion? Woods170 had mentioned that NASA was considering using FH for other Gateway modules but I don't think that anything has been announced on that front.
It's up to NASA if they want to keep completed Gateway components in ground or orbital storage at the Gateway, if the Orion don't have a ride.

As for getting crew to the Gateway if the SLS Block 1B is unable to met the schedule and the ICPS stage isn't available. Then the SpaceX HLS Starship could be press into service as crew transport and maybe orbital tug between LEO and NRHO, if it is operational.
« Last Edit: 10/18/2023 09:26 am by Zed_Noir »

Offline DanClemmensen

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Re: OIG report: NASA transitioning SLS to commercial contract
« Reply #50 on: 10/17/2023 02:30 pm »
What is the point of launching IHab, Esprit and the Airlock with FH if you can't get to them with Orion? Woods170 had mentioned that NASA was considering using FH for other Gateway modules but I don't think that anything has been announced on that front. 

Still actively being worked on by groups at NASA. The idea is to use NG's Cygnus-based tug vehicles to deliver the modules to Gateway. Remember: before HALO was merged with PPE, it was supposed to be delivered as a separate module, where a modified service section of a Cygnus CRS vehicle would act as the tug. Which would make perfect sense given that the HALO pressure hull is directly derived from a Cygnus pressure hull. The major difference between a standard Cygnus and the originally conceived HALO, was that the service section (the tug) could detach itself from the pressure module.

Can a Cygnus with an attached Gateway element perform the RPOD maneuvers to actually dock the element to Gateway? Could the Dragon XL (if it existed) do this? I think the Gateway element would need to be mated to the tug prior to launch from Earth, since AFAIK the element is not equipped with reaction wheels or thrusters and so cannot act as a docking target. Is FH powerful enough to launch this combined payload?

Offline pochimax

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Re: OIG report: NASA transitioning SLS to commercial contract
« Reply #51 on: 10/17/2023 09:38 pm »
Is FH powerful enough to launch this combined payload?

Good question. Maybe just wait for Starship (launcher)

***

As for the tugs, many modifications would have to be made to the currently existing hardware. Here is one of the 2019 proposals. I don't think any of this will be cheap (hundreds of millions of dollars per mission), but compared to the cost of the SLS, I imagine it will be a bargain.

https://twitter.com/northropgrumman/status/1190687724040269824

Offline pochimax

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Re: OIG report: NASA transitioning SLS to commercial contract
« Reply #52 on: 10/17/2023 09:44 pm »
Quote
It's up to NASA if they want to keep completed Gateway components in ground or orbital storage at the Gateway

I do not share this opinion. ESA and JAXA could decide to launch their modules and continue with the Gateway on their own. They could even invite India.

I don't see NASA abandoning Gateway, it would be an international ridicule and a mess... It would destroy the intricate collaboration currently existing between NASA and ESA/JAXA, both in the Artemis program and in LEO.

Therefore, for the commercial alternative to SLS I understand that it must be kept in the equation that the additional Gateway modules will be launched as designed. The only question is whether they will do so as payloads alongside the Orion on the SLS or through commercial alternatives.
« Last Edit: 10/17/2023 09:46 pm by pochimax »

Offline Zed_Noir

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Re: OIG report: NASA transitioning SLS to commercial contract
« Reply #53 on: 10/18/2023 09:39 am »
Quote
It's up to NASA if they want to keep completed Gateway components in ground or orbital storage at the Gateway

I do not share this opinion. ESA and JAXA could decide to launch their modules and continue with the Gateway on their own. They could even invite India.

I don't see NASA abandoning Gateway, it would be an international ridicule and a mess... It would destroy the intricate collaboration currently existing between NASA and ESA/JAXA, both in the Artemis program and in LEO.

Therefore, for the commercial alternative to SLS I understand that it must be kept in the equation that the additional Gateway modules will be launched as designed. The only question is whether they will do so as payloads alongside the Orion on the SLS or through commercial alternatives.
To clarified about the 'orbital storage'  in my previous post. It meant the modules are send to to the Gateway at NRHO and docked with the station. Waiting for the next crew tour for module(s) commissioning. Since it is much easier to keeping station on orbit with one object rather many objects.

Online woods170

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Re: OIG report: NASA transitioning SLS to commercial contract
« Reply #54 on: 10/18/2023 02:05 pm »
What is the point of launching IHab, Esprit and the Airlock with FH if you can't get to them with Orion? Woods170 had mentioned that NASA was considering using FH for other Gateway modules but I don't think that anything has been announced on that front. 

Still actively being worked on by groups at NASA. The idea is to use NG's Cygnus-based tug vehicles to deliver the modules to Gateway. Remember: before HALO was merged with PPE, it was supposed to be delivered as a separate module, where a modified service section of a Cygnus CRS vehicle would act as the tug. Which would make perfect sense given that the HALO pressure hull is directly derived from a Cygnus pressure hull. The major difference between a standard Cygnus and the originally conceived HALO, was that the service section (the tug) could detach itself from the pressure module.

Can a Cygnus with an attached Gateway element perform the RPOD maneuvers to actually dock the element to Gateway? Could the Dragon XL (if it existed) do this? I think the Gateway element would need to be mated to the tug prior to launch from Earth, since AFAIK the element is not equipped with reaction wheels or thrusters and so cannot act as a docking target. Is FH powerful enough to launch this combined payload?

Emphasis mine.

Cygnus service section as-is can't do the "D" portion of RPOD. Hence why NASA and NG are looking into a modified version of the Cygnus service section. Docking of new modules will be needed multiple times, because the initial PPE-HALO combination lacks Canadarm3 to support a MRM-style assisted docking of additional modules. In fact, as far as I know, under current planning Canadarm3 won't be delivered to Lunar Gateway until after iHAB has arrived. And I've heard exactly nothing about the vehicle that is to deliver Canadarm3 (Dragon-XL, HTV-X, mounted on a new module, ??)
« Last Edit: 10/18/2023 02:07 pm by woods170 »

Offline yg1968

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Re: OIG report: NASA transitioning SLS to commercial contract
« Reply #55 on: 10/18/2023 02:14 pm »
What is the point of launching IHab, Esprit and the Airlock with FH if you can't get to them with Orion? Woods170 had mentioned that NASA was considering using FH for other Gateway modules but I don't think that anything has been announced on that front. 

Still actively being worked on by groups at NASA. The idea is to use NG's Cygnus-based tug vehicles to deliver the modules to Gateway. Remember: before HALO was merged with PPE, it was supposed to be delivered as a separate module, where a modified service section of a Cygnus CRS vehicle would act as the tug. Which would make perfect sense given that the HALO pressure hull is directly derived from a Cygnus pressure hull. The major difference between a standard Cygnus and the originally conceived HALO, was that the service section (the tug) could detach itself from the pressure module.

Can a Cygnus with an attached Gateway element perform the RPOD maneuvers to actually dock the element to Gateway? Could the Dragon XL (if it existed) do this? I think the Gateway element would need to be mated to the tug prior to launch from Earth, since AFAIK the element is not equipped with reaction wheels or thrusters and so cannot act as a docking target. Is FH powerful enough to launch this combined payload?

Emphasis mine.

Cygnus service section as-is can't do the "D" portion of RPOD. Hence why NASA and NG are looking into a modified version of the Cygnus service section. Docking of new modules will be needed multiple times, because the initial PPE-HALO combination lacks Canadarm3 to support a MRM-style assisted docking of additional modules. In fact, as far as I know, under current planning Canadarm3 won't be delivered to Lunar Gateway until after iHAB has arrived. And I've heard exactly nothing about the vehicle that is to deliver Canadarm3 (Dragon-XL, HTV-X, mounted on a new module, ??)

Canadarm 3 will be delivered by Dragon XL. It was in the RFP and it's been mentioned a number of times by NASA.

Offline DanClemmensen

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Re: OIG report: NASA transitioning SLS to commercial contract
« Reply #56 on: 10/18/2023 02:40 pm »
What is the point of launching IHab, Esprit and the Airlock with FH if you can't get to them with Orion? Woods170 had mentioned that NASA was considering using FH for other Gateway modules but I don't think that anything has been announced on that front. 

Still actively being worked on by groups at NASA. The idea is to use NG's Cygnus-based tug vehicles to deliver the modules to Gateway. Remember: before HALO was merged with PPE, it was supposed to be delivered as a separate module, where a modified service section of a Cygnus CRS vehicle would act as the tug. Which would make perfect sense given that the HALO pressure hull is directly derived from a Cygnus pressure hull. The major difference between a standard Cygnus and the originally conceived HALO, was that the service section (the tug) could detach itself from the pressure module.

Can a Cygnus with an attached Gateway element perform the RPOD maneuvers to actually dock the element to Gateway? Could the Dragon XL (if it existed) do this? I think the Gateway element would need to be mated to the tug prior to launch from Earth, since AFAIK the element is not equipped with reaction wheels or thrusters and so cannot act as a docking target. Is FH powerful enough to launch this combined payload?

Emphasis mine.

Cygnus service section as-is can't do the "D" portion of RPOD. Hence why NASA and NG are looking into a modified version of the Cygnus service section. Docking of new modules will be needed multiple times, because the initial PPE-HALO combination lacks Canadarm3 to support a MRM-style assisted docking of additional modules. In fact, as far as I know, under current planning Canadarm3 won't be delivered to Lunar Gateway until after iHAB has arrived. And I've heard exactly nothing about the vehicle that is to deliver Canadarm3 (Dragon-XL, HTV-X, mounted on a new module, ??)
If you need Canadarm to already be on the Gateway to berth new Gateway components, then the Canadarm must be delivered with a components that can  actively dock, right? So you you need to solve the docking problem for component deliveries up to and including the Canadarm delivery. Of course, you can deliver Canadarm on any SpaceX HLS. It docks to Gateway as part of its primary mission and it has the spare payload capacity.  This would solve the docking problem, but a tug is still needed for the rest of the component delivery.

The notional Dragon XL has a payload capacity of 5000 kg. The nominal I-Hab mass is 10,000 kg. If I-HAB is not delivered by the SLS block 1B during Artemis IV, I don't think NASA can count on an unmodified FH+Dragon XL to do the job. I don't know what FH is used for  the notional Dragon XL mission. Perhaps a fully-expended FH would do the job.

Offline pochimax

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Re: OIG report: NASA transitioning SLS to commercial contract
« Reply #57 on: 10/18/2023 06:54 pm »
Quote
Of course, you can deliver Canadarm on any SpaceX HLS.

I don't know if it would be that simple.
For example, in Grumman's proposal, the robotic arm travels on the outside of the cargo ship, exposed to space, but launched inside a fairing, and once on the Gateway the robot self-deploys (I think).
I don't know how the robot arm would travel on a Dragon XL, I imagine it would be in a similar way since this ship is also launched protected by a fairing in a Falcon Heavy.

(See here again, after 1.20' )

twitter.com/northropgrumman/status/1190687724040269824

However, I'm not sure how it would travel on a Starship HLS. It cannot travel on the outside of the ship because it is not launched protected. Does it have a non-pressurized cargo compartment? And how would the robot arm be deployed from the compartment until it reaches the nearest module?

I am not sure that the transport and deployment of the robotic arm did not require certain important modifications to the Starship HLS.
« Last Edit: 10/18/2023 07:05 pm by pochimax »

Offline DanClemmensen

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Re: OIG report: NASA transitioning SLS to commercial contract
« Reply #58 on: 10/18/2023 08:54 pm »

However, I'm not sure how it would travel on a Starship HLS. It cannot travel on the outside of the ship because it is not launched protected. Does it have a non-pressurized cargo compartment? And how would the robot arm be deployed from the compartment until it reaches the nearest module?

I am not sure that the transport and deployment of the robotic arm did not require certain important modifications to the Starship HLS.
My assumption is that it can travel in the garage. The garage has a large hatch that can be opened to space. I don't know if the garage is pressurizable or not, but in normal operation on the lunar surface that big hatch is opened to vacuum to move big cargo onto the big elevator.

Yes, the HLS might need some external attachment points to let the canadarm "walk" onto the Gateway. However, the HLS visits Gateway to support crew. The crew can EVA to move the Canadarm.

Offline pochimax

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Re: OIG report: NASA transitioning SLS to commercial contract
« Reply #59 on: 10/18/2023 09:36 pm »
My assumption is that it can travel in the garage. The garage has a large hatch that can be opened to space. I don't know if the garage is pressurizable or not, but in normal operation on the lunar surface that big hatch is opened to vacuum to move big cargo onto the big elevator.

Yes, the HLS might need some external attachment points to let the canadarm "walk" onto the Gateway. However, the HLS visits Gateway to support crew. The crew can EVA to move the Canadarm.

I understand the concept of the Starship garage, but I imagine it to be too far from the Gateway modules for the robotic arm to be able to move from inside the garage to the closest module. It may not be so. I don't know.

An EVA to help the robot arm seems complex to me and that NASA would try to avoid doing it.

The problem with Starship HLS's external attachment points for the robotic arm is getting them to survive atmospheric friction during launch. It may not be feasible. Not sure about this.

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