Quote from: Robotbeat on 10/14/2023 11:50 amWhich 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.
Which talks about commercial alternatives to SLS. Since Orion is the only payload, it’s kind of important.
Quote from: yg1968 on 10/15/2023 04:18 amThe 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?
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.
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.
Quote from: DanClemmensen on 10/16/2023 02:57 pmMy 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.
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.
Quote from: DanClemmensen on 10/15/2023 03:35 pmQuote from: yg1968 on 10/15/2023 04:18 amThe 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.QuoteAs 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.
Quote from: yg1968 on 10/15/2023 11:40 pmQuote from: joek on 10/15/2023 11:24 pmQuote from: OTV Booster on 10/15/2023 08:28 pmCan 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.
Quote from: joek on 10/15/2023 11:24 pmQuote from: OTV Booster on 10/15/2023 08:28 pmCan 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.
Quote from: OTV Booster on 10/15/2023 08:28 pmCan 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.
Can you expand on SLS and Orion being joined at the hip? Straight up question. No snark.
Quote from: Zed_Noir on 10/16/2023 07:55 amQuote from: yg1968 on 10/15/2023 11:40 pmQuote from: joek on 10/15/2023 11:24 pmQuote from: OTV Booster on 10/15/2023 08:28 pmCan 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.
Quote from: yg1968 on 10/17/2023 12:38 amQuote from: Zed_Noir on 10/16/2023 07:55 amQuote from: yg1968 on 10/15/2023 11:40 pmQuote from: joek on 10/15/2023 11:24 pmQuote from: OTV Booster on 10/15/2023 08:28 pmCan 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.
Quote from: DanClemmensen on 10/17/2023 01:19 amQuote from: yg1968 on 10/17/2023 12:38 amQuote from: Zed_Noir on 10/16/2023 07:55 amQuote from: yg1968 on 10/15/2023 11:40 pmQuote from: joek on 10/15/2023 11:24 pmQuote from: OTV Booster on 10/15/2023 08:28 pmCan 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...
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.
Quote from: yg1968 on 10/17/2023 12:38 amWhat 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.
Is FH powerful enough to launch this combined payload?
It's up to NASA if they want to keep completed Gateway components in ground or orbital storage at the Gateway
QuoteIt's up to NASA if they want to keep completed Gateway components in ground or orbital storage at the GatewayI 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.
Quote from: woods170 on 10/17/2023 08:15 amQuote from: yg1968 on 10/17/2023 12:38 amWhat 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?
Quote from: DanClemmensen on 10/17/2023 02:30 pmQuote from: woods170 on 10/17/2023 08:15 amQuote from: yg1968 on 10/17/2023 12:38 amWhat 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, ??)
Of course, you can deliver Canadarm on any SpaceX HLS.
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.