The moment you launch a separate Block 1B SLS to handle the lander, you limit yourself to storables, because the second SLS will still be under construction when you launch the first one.
Quote from: TheRadicalModerate on 11/16/2019 10:14 pmThe moment you launch a separate Block 1B SLS to handle the lander, you limit yourself to storables, because the second SLS will still be under construction when you launch the first one. This is a bad assumption. There are two mobile launchers. If NASA wants, they are fully capable of outfitting high bay 1 and stacking a second SLS at the same time as the first.
The current Mobile Launch Platform (MLP) can only handle the Block 1 configuration, and the new MLP is being built to handle Block 1B and Block 2, so if there was a need to launch more than one SLS per year then it's likely they would only use the new MLP (it can handle multiple launches per year). The only opportunity to use both MLP would be at the transition from Block 1 to Block 1B/2, and I think that is too soon to allow a plan to do that.
Quote from: Coastal Ron on 11/16/2019 11:22 pmThe current Mobile Launch Platform (MLP) can only handle the Block 1 configuration, and the new MLP is being built to handle Block 1B and Block 2, so if there was a need to launch more than one SLS per year then it's likely they would only use the new MLP (it can handle multiple launches per year). The only opportunity to use both MLP would be at the transition from Block 1 to Block 1B/2, and I think that is too soon to allow a plan to do that.Even with the current ML configuration it would be entirely possible to launch a Block 1 crewed SLS in conjunction with a Block 1B cargo SLS with very little turnaround if high bay 1 is set up for it.
When I was researching this topic it was implied that only the new MLP could handle the Orion configuration. But it wasn't stated.
However there is only one point in the future where flying a Block 1 and a Block 1B significantly less than 12 months apart can happen, and that is right around 2024. And we know that Boeing doesn't have ability, currently, to build more than one SLS per year - it would take an act of Congress to fund the ability to build more than one per year.
Quote from: Coastal Ron on 11/17/2019 12:24 amWhen I was researching this topic it was implied that only the new MLP could handle the Orion configuration. But it wasn't stated.Can you clarify what you mean by this?Quote from: Coastal Ron on 11/17/2019 12:24 amHowever there is only one point in the future where flying a Block 1 and a Block 1B significantly less than 12 months apart can happen, and that is right around 2024. And we know that Boeing doesn't have ability, currently, to build more than one SLS per year - it would take an act of Congress to fund the ability to build more than one per year.I'm quite certain that Boeing's lander proposal isn't going to gimp non-lander SLS production. That would go against the terms laid down for using SLS in the HLS solicitation.In other words, the only way they can make a proposal that complies with the HLS requirements is to push the production rate above 1 per year.
HLS program will pay for the additional cost of the launch vehicle.
You know, according to this press release from 2014, it only cost about $100M to outfit VAB High Bay 3 for SLS. I see no reason that shouldn't hold with High Bay 1.So if it only costs ~$100M to enable dual launch of Block 1 and Block 1B, there's really nothing stopping NASA from doing so if such a capability is ever needed.
Stacking isn't the long pole in the tent. Based on behavior so far, manufacturing is.
And how much more money would you be planning on throwing at EGS to get two stacks running at the same time, with two sets of SRBs? Good thing that there won't be any stray LOX domes lounging about.
I guess you could store a core in the VAB, then finish stacking just as the second one came out of Stennis. But it's still likely to take a month or two to stack the second SLS--especially one with an Orion on it--after the first one has rolled out. That's still too long for cryogenics without a bunch of low-TRL stuff being required by Artemis.
Just to be clear, if you're going to launch two SLSes nearly simultaneously for Artemis 3, you're not talking about some dim, distant eventuality. You'd pretty much have to have the contracts in place by now. Oh, yeah: Don't forget that you won't be doing any High Bay expansion work that'll interfere with Artemis 1.
I think it's much more likely that they simply build an AE/DE that use storables.
Let's see. Artemis 3 is 2024. HB-3 modifications were contracted in 2014, and finished in 2017. 3 years. Assuming that there's no speed improvements and that they want to finish VAB modifications before the end of 2023, that gives them until the end of next year to start working on it. So yeah, they'd have to act soon, but it's not yet been ruled out as an option.Also, I don't see where there'd be much possibility for interference. High Bay 1 and High Bay 3 don't share any equipment insofar as stacking rockets goes. There'd be more possibility of conflicts with High Bay 2 (which will eventually start being equipped for OmegA) than conflicts with High Bay 3.
They're not going to let somebody even breathe on the VAB configuration with an SLS in there. And you've got Artemis 2 in there somewhere. How long does stacking take? Four months? So you're going to do all the work between (optimistically) mid 2021 and mid-2022? Or (more realistically) late 2023?
Quote from: Coastal Ron on 11/17/2019 12:24 amWhen I was researching this topic it was implied that only the new MLP could handle the Orion configuration. But it wasn't stated.Can you clarify what you mean by this?
Quote from: Coastal Ron on 11/17/2019 12:24 amHowever there is only one point in the future where flying a Block 1 and a Block 1B significantly less than 12 months apart can happen, and that is right around 2024. And we know that Boeing doesn't have ability, currently, to build more than one SLS per year - it would take an act of Congress to fund the ability to build more than one per year.I'm quite certain that Boeing's lander proposal isn't going to gimp non-lander SLS production. That would go against the terms laid down for using SLS in the HLS solicitation.
In other words, the only way they can make a proposal that complies with the HLS requirements is to push the production rate above 1 per year.
From what I read it seemed that the Orion would only be able to launch from either a modified version of the current MLP, or the new MLP that will be needed for the Block 1B and Block 2. That needs to be verified though.
Just because Boeing bid it doesn't mean they are likely to do it. I think they would need quite a bit of money to do a non-NASA launch of the SLS.
QuoteIn other words, the only way they can make a proposal that complies with the HLS requirements is to push the production rate above 1 per year.That seems to be the case. Which is possible, but only if NASA pours more money and personnel into the SLS facility.
Their partnership with Intuitive Machines (which makes methalox engines) wouldn't make much sense if an all-storable lander was their game-plan.
“Our typical propulsion partner tends to be Aerojet Rocketdyne,” he said. “We are looking at alternate sources, too, depending on their maturity, but there are some off-the shelf engines that we’re looking at from Aerojet Rocketdyne, that are flying on commercial crew, so existing engines.”Boeing is looking at storable hypergolic propellant systems for the engines on the 2024 lunar landing mission, McGrath said.
Quote from: TripleSeven on 11/15/2019 05:52 pmBoth vehicles can be opreated independent of a gateway station...which if there is a Boeing plan, cannot be built..Baseless speculation.
Both vehicles can be opreated independent of a gateway station...which if there is a Boeing plan, cannot be built..
So the 2021 NASA budget request throws some wrenches into Boeing's plan:1. It defers SLS Block 1B indefinitely2. It assigns Europa Clipper to commercial LV because otherwise it would reduce the SLS assigned to Artemis, which basically says NASA doesn't expect more than 3 SLS by 2024Congress may restore SLS Block 1B, but NASA will be the one who pick the winner of HLS, it's pretty clear NASA has no confidence that Boeing can work on Block 1B in parallel or increase the production rate of SLS cores, it would be interesting to see how this non-confidence translates into their evaluation of Boeing's HLS proposal.