Quote from: pochimax on 05/30/2023 08:16 pmQuote from: Zed_Noir on 05/29/2023 08:37 pmIF someone wants a "bigger" Orion service module. There always the option of docking the current Orion stack to a pre-positioned stripped down SpaceX HLS lander variant with no landing hardware and full tanks in LEO. Plus the bonus of the pressurized volume and pre-positioned cargo that will be available in the lander variant.Of course getting the Orion to LEO with the SLS will be optional. You need to connect that kind of Moonship with Orion with all the requirements... At that point, will be far cheaper to modify the ESM instead of making that "Moonshipstein". Moreover if it is the eurpeans who pay for it as a contribution for Artemis or whatever the name of the NASA cislunar / mars space program in the '30s, '40s, etc.You do realize that the SpaceX HLS lander is supposed to docked with Orion and act as a mothership, prior to the Gateway platform being available.IIRC, the length of the Orion ESM is limited by roof ceiling in the VAB. Could make the ESM wider. But that is basically developing a new spacecraft. The European ESM derived from the ATV is the form factor it is because it cost too much change from it's previous form factor.The Europeans should be considering something else to contributed in the future instead of more Orion ESM to the Artemis program.
Quote from: Zed_Noir on 05/29/2023 08:37 pmIF someone wants a "bigger" Orion service module. There always the option of docking the current Orion stack to a pre-positioned stripped down SpaceX HLS lander variant with no landing hardware and full tanks in LEO. Plus the bonus of the pressurized volume and pre-positioned cargo that will be available in the lander variant.Of course getting the Orion to LEO with the SLS will be optional. You need to connect that kind of Moonship with Orion with all the requirements... At that point, will be far cheaper to modify the ESM instead of making that "Moonshipstein". Moreover if it is the eurpeans who pay for it as a contribution for Artemis or whatever the name of the NASA cislunar / mars space program in the '30s, '40s, etc.
IF someone wants a "bigger" Orion service module. There always the option of docking the current Orion stack to a pre-positioned stripped down SpaceX HLS lander variant with no landing hardware and full tanks in LEO. Plus the bonus of the pressurized volume and pre-positioned cargo that will be available in the lander variant.Of course getting the Orion to LEO with the SLS will be optional.
Quote from: Zed_Noir on 05/30/2023 09:52 pmQuote from: pochimax on 05/30/2023 08:16 pmQuote from: Zed_Noir on 05/29/2023 08:37 pmIF someone wants a "bigger" Orion service module. There always the option of docking the current Orion stack to a pre-positioned stripped down SpaceX HLS lander variant with no landing hardware and full tanks in LEO. Plus the bonus of the pressurized volume and pre-positioned cargo that will be available in the lander variant.Of course getting the Orion to LEO with the SLS will be optional. You need to connect that kind of Moonship with Orion with all the requirements... At that point, will be far cheaper to modify the ESM instead of making that "Moonshipstein". Moreover if it is the eurpeans who pay for it as a contribution for Artemis or whatever the name of the NASA cislunar / mars space program in the '30s, '40s, etc.You do realize that the SpaceX HLS lander is supposed to docked with Orion and act as a mothership, prior to the Gateway platform being available.IIRC, the length of the Orion ESM is limited by roof ceiling in the VAB. Could make the ESM wider. But that is basically developing a new spacecraft. The European ESM derived from the ATV is the form factor it is because it cost too much change from it's previous form factor.The Europeans should be considering something else to contributed in the future instead of more Orion ESM to the Artemis program.The door height of the VAB is 456 ft. The ML-1 tower when on the crawler transporter is about 400 ft tall. There's plenty of clearance for a taller rocket. The EUS on the Block 1B will increase the height of the SLS by about 30 ft.
I was in doubt of starting a new topic or using this one. I decided to do the later.ESA supplies the Orion ESM (European Service Module), as barter element contribution to ISS and Gateway.The ESM's for Orion 1 to 6 are under construction. I as European want ESA to be relieved from this contribution (/burden) to the Artemis program. So it can be used to fund a European payload return (human) launch capability.This would cause a problem for NASA, because Orion doesn't function without ESM.NASA would be required to fund the development of a new Orion service module; possibly this could go alongside with enlarging it. In my opinion launching Orion (humans) on a launcher with giant solid rocket motors is not wise. It causes very stingent requirements for the launch escape system.This leads me to the idea to launch Orion from a commercial launch vehicle.If the launch escape system is integrated into the service module; similar to Boeing Starliner, the reduced mass for the launch escape system can be traded by increasing the size and propulsive capability of the service module. I think MethaLOx would be a good choice for the new service module & launch escape system. How are you thinking about this?
ESA supplies the Orion ESM (European Service Module), as barter element contribution to ISS and Gateway.The ESM's for Orion 1 to 6 are under construction. I as European want ESA to be relieved from this contribution (/burden) to the Artemis program. So it can be used to fund a European payload return (human) launch capability.This would cause a problem for NASA, because Orion doesn't function without ESM.NASA would be required to fund the development of a new Orion service module; possibly this could go alongside with enlarging it.
The original conceptual Orion SM, during CPX, was larger. The original Orion CM diameter was to be a far too large ~6m, and was downsized to a still too massive 5.02m. The original SM was to be the same diameter prior to the ESA taking the contract for it. The ESA builds the current SM on a common bus which they already use for multiple purposes. This is why it has a smaller diameter and also ∴ requires jetisonable cover panels. In the Apollo program, the size ratio of SM to CM was > the same ratio between Orion SM and CM. This is because the Apollo SM had to provide the ΔV of the full stack for LOI, and then the ΔV for the CSM for TEI. In the CPX program, the Altair lander would have utilized Hydrolox prop (high iSP, low density, high volumetric tank requirements) for the ΔV of the full stack into LOI, and then the same engine and tanks for landing. The Orion SM in CXP would only have to provide ΔV for the CSM for TEI. As the Orion was carried over to the Artemis Program, its SM still only has to provide ΔV for TEI and no ΔV for LOI. Since Artemis/Orion lunar orbit will be NRHO, LOI requirements are quite different from Apollo.
If I remember correctly, the NRHO orbit was picked instead of LLO because of the limitations in ΔV of the service module. Performance limited requirements instead of requirements driving performance. NASA had created a chart of ΔV requirements to get to different possible place to park Orion and they had little choice but to choose NRHO since it fit what they had in development.
The original conceptual Orion SM, during CPX, was larger. The original Orion CM diameter was to be a far too large ~6m, and was downsized to a still too massive 5.02m. The original SM was to be the same diameter prior to the ESA taking the contract for it.
The ESA builds the current SM on a common bus which they already use for multiple purposes.
This is why it has a smaller diameter and also ∴ requires jetisonable cover panels.
That is completely correct. I stated this partially in my last sentence above, and have edited to expand that. I was just looking at that chart which is embedded in this article: https://space.stackexchange.com/questions/23992/why-is-a-near-rectilinear-halo-orbit-proposed-for-lop-g-formerly-known-as-deep