1. Someone said, somewhere here, that when facility to manufacture Saturn V 1st and 2nd stages were for 6 Saturn V's per year. So, the facility can at least do 6. 2. The VAB can process at least 4 at a time. It has 4 bays. They would have to build at least 4 platforms.
Someone said, somewhere here, that when facility to manufacture Saturn V 1st and 2nd stages were for 6 Saturn V's per year. So, the facility can at least do 6.
So, can ATK manufacture 12 solid boosters a year to match?
I guess if they are going to Mars using SLS, they are probably going to have to use other launchers to launch components, fuel, SEP tugs, habitats, or something to LEO or to L2 and assemble to go to Mars.
More SLS launches would equal less in space assembly.
NASA simply desgined the factory for SLS and for an flight rate of 1-2 an year and it likely was an attractive thing to do(complies with the law--which states nothing about production rate). President not actively engaged(not his baby) and does nothing to further his goal(commercialization of human spaceflight). Saves money(designing for smaller scales of production is cheaper than larger scales). All parties are fine with it. It isn't one tool, it is the whole thing.
The evolvable Mars campaign has a maximum of 3 SLS launches during certain years. Do we really need to up the SLS production rate beyond 2 a year? Assuming NASA only uses SLS they could store extra cores made during the decade of once a year flights and then use them for the years that require 3 flights. Block 2B uses the same core and upper stage as Block 1B.
Alternatively you could tag team SLS with Vulcan and Falcon to launch some elements of the mission. That should get rid of the need to launch more than 2 SLS's a year.
Sure, or even go all commercial. Letting commercial launchers into the mix opens Pandora's box for NASA, since it will highlight the disadvantages of a government-run HLV transportation system - chief of which would be cost and redundancy. Quite the conundrum...
Quote from: 93143 on 09/27/2015 09:15 pm...We were discussing marginal costs associated with changes in flight rate...What was the original supposition that lead to this discussion about "marginal cost"? I think it's been a while, and I've forgotten.
...We were discussing marginal costs associated with changes in flight rate...
Is "marginal cost" something that will play into the discussion about the future of the SLS? In other words, is a future NASA Administrator going to be called in front of Congress and asked what the "marginal cost" is of the SLS, and that their answer will determine whether an additional SLS is authorized?Or are we talking about something that only accountants get excited about?
Do we really need to up the SLS production rate beyond 2 a year?
QuoteMore SLS launches would equal less in space assembly. There are trade-offs that negate that potential advantage.
Going all commercial wouldn't work IMHO. You would run into capacity and volume issues that I have pointed out previously.
A number of payloads as well as manned Orion launches wouldn't work on a Falcon Heavy or a Vulcan.
The best bet is to use commercial to supplement SLS.
Quote from: Endeavour_01 on 09/28/2015 08:54 pmDo we really need to up the SLS production rate beyond 2 a year?Do we really need a space program at all?Now, we probably don't need SLS making milk runs to the ISS. But I see no reason why a couple of heavy lunar landers per year (perhaps developed from existing upper stage technology, so as to save money vs. Altair) should be out of scope, except that Obama's "vision" seems to have sucked all the hope out of everybody. Add depots (with tankers), and you've freed up a couple of launches, but you still have to go past two per year if you want to do literally anything else on top of your six-month moon base rotation. Like, say, launch scientific probes to the outer planets, or large space telescopes, or BA-330s to cislunar space, or BA-2100s to LEO, or the notional giant black payloads that have been hinted about, or, y'know... go to Mars. Especially every two years...
I'd rather see a focus on landing on the Moon, practicing base building there, and developing a L2 station than trying to do a bare bones trip to Mars.
Quote from: spacenut on 09/28/2015 07:38 pm1. Someone said, somewhere here, that when facility to manufacture Saturn V 1st and 2nd stages were for 6 Saturn V's per year. So, the facility can at least do 6. 2. The VAB can process at least 4 at a time. It has 4 bays. They would have to build at least 4 platforms. Also, there is not only one pad for SLS.
Quote from: Jim on 09/28/2015 07:55 pmQuote from: spacenut on 09/28/2015 07:38 pm1. Someone said, somewhere here, that when facility to manufacture Saturn V 1st and 2nd stages were for 6 Saturn V's per year. So, the facility can at least do 6. 2. The VAB can process at least 4 at a time. It has 4 bays. They would have to build at least 4 platforms. Also, there is not only one pad for SLS.Clarification please.Are you saying there is one pad, or more than 1 pad for SLS?
So if they had two MLP's and used two bays to set up a couple of SLS's, they could what launch 1 a week?
So, it seems to me the bottleneck for launching more than two a year is production at McCloud facility.
Now is seems they should have designed a clean sheet with reusable boosters and core, or at least a return pod with the engines.
Quote from: spacenut on 09/30/2015 09:21 pmSo if they had two MLP's and used two bays to set up a couple of SLS's, they could what launch 1 a week? No, booster stacking takes longer than that. Add in upper stage and payload and VAB time is much more than Shuttle.
Quote from: spacenut on 09/28/2015 07:38 pm1. Someone said, somewhere here, that when facility to manufacture Saturn V 1st and 2nd stages were for 6 Saturn V's per year. So, the facility can at least do 6. 2. The VAB can process at least 4 at a time. It has 4 bays. They would have to build at least 4 platforms. 1. Not true. Space/volume does not determine capability. The tooling does. Anyways, it is a shared facility and there are other users2. See above. The 4 bays were never fully outfitted and even during shuttle, only two were outfitted. Also, there is not only one pad for SLS.
I'm pretty sure that Jim meant "there is now only one pad for SLS", since NASA leased pad 39A to SpaceX. The implication is that SLS cannot have a higher launch rate e.g. Shuttle because of the limitation of a single SLS launch pad 39B.
Quote from: Mark S on 09/30/2015 08:59 pmI'm pretty sure that Jim meant "there is now only one pad for SLS", since NASA leased pad 39A to SpaceX. The implication is that SLS cannot have a higher launch rate e.g. Shuttle because of the limitation of a single SLS launch pad 39B.There is one pad and one ML. Original maps of Complex 39 show locations for 5 potential pads, but it is doubtful in the extreme that any more would ever be developed. Even if they wanted to, environmental impact reviews would most surely prevent it anyway.