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#260
by
Endeavour_01
on 08 May, 2015 14:52
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The ISS production line is shut down and Boeing has no incentive to restart it when they can try to sell existing SLS tooling at Michoud that is already up and running. Don't jump to conclusions - for all that is known, it would cost the same to build the two.
This right here. An ISS derived architecture would require restart of production lines that have been shut down for years. Why not just go with an architecture that fits into what you are building right now?
In my mind SLS derived habs are superior to ISS derived habs. More mass and more volume in fewer launches as well as less assembly required.
Well, less assembly in space maybe. But the assembly here on Earth is far more complicated, and more time
Smaller modules can be assembled in parallel in different factories, which is what happened with the ISS.
Less assembly in space is a good thing. Given the capabilities we are going to have in the coming years it doesn't make sense to follow the piecemeal approach of ISS (at least not totally). SLS/Orion won't be able to launch 4 or 5 times a year to cislunar space which is what we would need to happen if we were assembling an ISS type Mars hab or cis-lunar station. ISS took 12 years and something like 35 shuttle missions to complete. Even if we accept something 1/5th the size of ISS that is still around 7 human missions + the actual module launches just to assemble the ISS hab vs. 1 launch on SLS for an SLS derived hab.
Also the economy of scale for SLS will benefit greatly and our investment in developing SLS will pay off more.
Sure, more things committed to the SLS means the SLS will be utilized more. Time is the important factor though, since no missions have been approved, and none are in the 2-year budget Congress is on track to pass this year. There is a looming launch gap coming, where once the SLS becomes operational there won't be any payloads or missions for it to launch. Not a good situation to be in where you're claiming the SLS is so badly needed.
We will see what happens after the next Presidential election. I have laid out a scenario in other posts that will take care of SLS launches once a year after 2021 to at least 2025. If development starts on an SLS derived hab in say 2018 we could take advantage of the time from EM-1 to EM-2 by using the tooling available to construct the shell of the hab. Then we can spend the next 8 years finishing it and then launch it in 2026 as a cis-lunar station. I think that is doable. Then once we have gotten the assembly line established we can begin production on the Mars hab.
Although I think the next station will utilize inflatables such as BA330's, since the material they are made out of provide far better radiation protection outside of Earth's protection.
I think that the only competition SLS derived habs will face is the BA330. If they can be shown to work well and perform in space then they are a very very strong contender.
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#261
by
mike robel
on 08 May, 2015 20:40
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Using ISS technology for its modules in a hab does not mean it has to be the same dimensions and forms as they are on the space station. They could be made, for instance, into 33 foot diameter, two story Tuna Cans, as Zubrin proposes.
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#262
by
redliox
on 09 May, 2015 02:19
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Using ISS technology for its modules in a hab does not mean it has to be the same dimensions and forms as they are on the space station. They could be made, for instance, into 33 foot diameter, two story Tuna Cans, as Zubrin proposes.
The ISS modules were only their size because of shuttle bay limitations, otherwise they should just be sized for whatever launcher available. You talk to any Russian cosmonaut, and they would admit to envying the wider spaces the 'American' modules brought versus the tighter limits of their Mir-like modules. Bigger of course is better, at least psychologically for crew if not to give functional room. I'd favor the tuna can design, although technically it could be inflatable and put inside a mere 5 meter rocket fairing.
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#263
by
TrevorMonty
on 09 May, 2015 02:54
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I'm in favour of commercial modules eg Cygnus and especially larger Exoliner. An empty 2.7m Cygnus with service module should be about $100m, a 3.3m version with NASA supplied ECLSS should be well under $500m. It may not have a lot of room but is affordable and could be launched with Orion. The follow on modules should be cheaper with each one adding extra room an functionality.
Mission durations would build as DSH expands.
Being able to launch modules with the Orion would save $100m in launch costs.
If they want to upgrade a function eg the ECLSS, just fly another module, the old ECLSS module could be kept as spare, used as EAM, repositioned to new location or disposed of along with a load of rubbish.
Each module added to DSH would also doubles as a container for supplies.
Upgrading the ECLSS in a SLS DSH would require a large amount of astronaut time and could result a DSH with no ECLSS if upgrade runs into problems.
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#264
by
Coastal Ron
on 09 May, 2015 03:38
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The ISS modules were only their size because of shuttle bay limitations, otherwise they should just be sized for whatever launcher available.
Regardless the mode of transportation, we won't be able to afford to expand out into space if everything we build is a one-off design. Commodity construction is a proven way of dramatically lowering costs, and it allows for reduced sustaining costs too.
If we can't find the sweet spot between "good enough" and "inexpensive enough" we're never leaving this rock...
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#265
by
Raj2014
on 09 May, 2015 12:23
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What is wrong with just using Bigelow's inflatable habitats? It offers free space inside, multiple protection, comes in different sizes and it is compact when traveling to orbit then inflates afterwards.
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#266
by
rayleighscatter
on 09 May, 2015 14:15
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What is wrong with just using Bigelow's inflatable habitats? It offers free space inside, multiple protection, comes in different sizes and it is compact when traveling to orbit then inflates afterwards.
The big problem with a system based purely on inflatable modules is that it will have to go out fully supplied. It can't be that compact for launch when its full of equipment, food, etc.
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#267
by
Raj2014
on 09 May, 2015 14:51
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What is wrong with just using Bigelow's inflatable habitats? It offers free space inside, multiple protection, comes in different sizes and it is compact when traveling to orbit then inflates afterwards.
The big problem with a system based purely on inflatable modules is that it will have to go out fully supplied. It can't be that compact for launch when its full of equipment, food, etc.
They can send cargo on a separate launch vehicle, if it is not that expensive. SpaceX or another aerospace company can send it. Why not use the same materials used on the inflatable modules on other types of deep space habitats?
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#268
by
HIP2BSQRE
on 09 May, 2015 14:59
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The problem with SLS derived habitat plus service module is that needs to be launched on an SLS. Most likely a dedicated launch which means crew would most likely follow a year later. Being a NASA built module it would expensive and a one off.
Smaller habitats based commercially modules could be delivered using commercial LVs or included in a SLS Orion launch.
SLS also means you have the added expense of an sls launch...which will not be cheap.
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#269
by
Coastal Ron
on 09 May, 2015 15:11
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The big problem with a system based purely on inflatable modules is that it will have to go out fully supplied. It can't be that compact for launch when its full of equipment, food, etc.
You're stuck in the 60's with doing things the Apollo way, whose methodologies were based on different constraints. With modern capabilities it's now possible to maximize a launch for just one need, like capabilities or supplies, meaning you don't have to compromise either.
For instance, if a vehicle built on Earth has to carry supplies then it has to be built stronger in order to hold those supplies during launch. That is wasted mass in space, reducing the amount of useful mass you could have launched if you had dedicated the design to just functional needs. The same with supplies, in that we know how to launch cargo vehicles packed with supplies, so that is one less thing that needs to be funded.
We're not going anywhere if we have to rely on one-shot architecture, so the sooner we assume reusable vehicles and resupply are the norm, the better.
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#270
by
RonM
on 09 May, 2015 15:13
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The problem with SLS derived habitat plus service module is that needs to be launched on an SLS. Most likely a dedicated launch which means crew would most likely follow a year later. Being a NASA built module it would expensive and a one off.
Smaller habitats based commercially modules could be delivered using commercial LVs or included in a SLS Orion launch.
SLS also means you have the added expense of an sls launch...which will not be cheap.
An SLS derived DSH module, like any other module, can be reused and have a useful life of twenty to thirty years. Dedicating an SLS launch for DSH and waiting around a year for the crew is not an issue. However, it would be expensive.
The big advantage of using smaller modules is that can be launched on a wide variety of rockets. Other countries can contribute their launch services to the cause. Spreading the costs amongst international partners increases the chances of BEO exploration being funded. The biggest obstacle to BEO exploration isn't technical, it's financial.
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#271
by
rayleighscatter
on 09 May, 2015 15:51
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The big problem with a system based purely on inflatable modules is that it will have to go out fully supplied. It can't be that compact for launch when its full of equipment, food, etc.
You're stuck in the 60's with doing things the Apollo way, whose methodologies were based on different constraints. With modern capabilities it's now possible to maximize a launch for just one need, like capabilities or supplies, meaning you don't have to compromise either.
For instance, if a vehicle built on Earth has to carry supplies then it has to be built stronger in order to hold those supplies during launch. That is wasted mass in space, reducing the amount of useful mass you could have launched if you had dedicated the design to just functional needs. The same with supplies, in that we know how to launch cargo vehicles packed with supplies, so that is one less thing that needs to be funded.
We're not going anywhere if we have to rely on one-shot architecture, so the sooner we assume reusable vehicles and resupply are the norm, the better.
I was working under the assumption that NASA wanted to avoid any sort of lengthy orbital construction and outfitting involving multiple launches. Especially considering the Augustine Commission's recommendation of not launching a manned mission to do something that could be done autonomously or on the ground.
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#272
by
redliox
on 09 May, 2015 16:24
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I was working under the assumption that NASA wanted to avoid any sort of lengthy orbital construction and outfitting involving multiple launches. Especially considering the Augustine Commission's recommendation of not launching a manned mission to do something that could be done autonomously or on the ground.
Unsure if the Augustine Commission specified that. Most engineers at least acknowledge the SLS is capable of putting more mass up in a single sitting than the shuttle ever could.
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#273
by
rayleighscatter
on 09 May, 2015 17:33
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I was working under the assumption that NASA wanted to avoid any sort of lengthy orbital construction and outfitting involving multiple launches. Especially considering the Augustine Commission's recommendation of not launching a manned mission to do something that could be done autonomously or on the ground.
Unsure if the Augustine Commission specified that. Most engineers at least acknowledge the SLS is capable of putting more mass up in a single sitting than the shuttle ever could.
It was part of the reference of separating cargo and crew, and one of the major reasons why a simple task like delivering cargo to the ISS was made to be done autonomously/robotically rather than rolled into a crewed mission as with shuttle.
And a system like this wouldn't have to be a single launch but the components, I suspect, would have to be much more "plug and play" than ISS construction was. Spending several weeks just to properly assemble it is likely an additional manned launch, not to mention the additional time to then properly outfit the interior. This of course is all additionally complicated by the fact that none of spacecraft available to NASA (Orion, Dragon, CST100) are particularly suited to orbital assembly like shuttle was. So whatever goes up will have to require a minimum of on orbit fitting. So while an inflatable habitat can work well for non-technical habitable space (such as a crew eating/sleeping area) launching one or several and then outfitting them in orbit adds to complexity and safety.
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#274
by
the_other_Doug
on 09 May, 2015 18:47
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The problem with SLS derived habitat plus service module is that needs to be launched on an SLS. Most likely a dedicated launch which means crew would most likely follow a year later. Being a NASA built module it would expensive and a one off.
Smaller habitats based commercially modules could be delivered using commercial LVs or included in a SLS Orion launch.
SLS also means you have the added expense of an sls launch...which will not be cheap.
An SLS derived DSH module, like any other module, can be reused and have a useful life of twenty to thirty years. Dedicating an SLS launch for DSH and waiting around a year for the crew is not an issue. However, it would be expensive.
The big advantage of using smaller modules is that can be launched on a wide variety of rockets. Other countries can contribute their launch services to the cause. Spreading the costs amongst international partners increases the chances of BEO exploration being funded. The biggest obstacle to BEO exploration isn't technical, it's financial.
Y'all are taking the SLS production rate as a maximum flight rate, and that doesn't necessarily follow.
I've heard production rates for SLS estimated at between one and two a year. That doesn't mean you have to fly them at that rate, though.
Let's say that Congress approves a manned Mars expedition in 2023, after SLS has flown and Orion has flown manned. Let's say the launch date for the expedition is designed for 2030.
That gives everyone 6 years or so to design and test equipment -- DSH designs, ECLSS designs, etc. -- and put together all of the modules needed. During that time, if we can make two SLS vehicles a year, we could have made a dozen of them. And you can put three at a time together in the VAB, roll them out to the pad, and launch them every month or two. Do your VAB flow so you can launch six SLS vehicles in a year, if not more. It has been done with the Saturn V and with the Shuttle, so I am pretty sure it could be done with SLS, given enough parts to put together.
You could have enough boost capability, launched over the course of six to 12 months, to lift into LEO enough equipment for two full expeditions, I think. All without using Falcon Heavy, Vulcan Heavy or even Musk's BFR.
Just sayin'...
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#275
by
newpylong
on 09 May, 2015 21:24
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Only High Bay 3 is being rebuilt for SLS processing and there is only a single ML so only 1 vehicle can be integrated for launch at a time. That said, this is not STS - vehicle processing time is going to be greatly reduced.
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#276
by
the_other_Doug
on 10 May, 2015 03:07
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Only High Bay 3 is being rebuilt for SLS processing and there is only a single ML so only 1 vehicle can be integrated for launch at a time. That said, this is not STS - vehicle processing time is going to be greatly reduced.
Sure. But in my scenario, you commit to the Mars expedition a good six or seven years before your Busy Year, when you're gonna try to launch three or four of the beasts within, say, a 9-month period. With that lead time, you could rebuild one of the other High Bays, refurb the other C-T, and build a second ML. That would be, relatively, a fraction of the cost of the other parts of the program you'd be committed to funding if you really wanted to send an expedition to Mars, I would think...
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#277
by
Coastal Ron
on 10 May, 2015 03:34
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I was working under the assumption that NASA wanted to avoid any sort of lengthy orbital construction and outfitting involving multiple launches.
You can't go far with one launch that includes humans, and the last Mars Design Reference Architecture (DRM 5.0) assumed some degree of assembly in LEO, so NASA is not opposed to in-orbit assembly. Heck, the ISS has proved that we can do it for both in-orbit assembly and resupply, so I'm not sure why anyone would be concerned.
Especially considering the Augustine Commission's recommendation of not launching a manned mission to do something that could be done autonomously or on the ground.
Not sure how that has anything to do with this since the assumption is that the DSH - which is a Deep Space HABITAT - would be for humans, not robots.
Another thing to consider is that even if such a habitat launched fully provisioned, it would still need to be re-provisioned periodically. Unless you're assuming a one-shot DSH, which would be kind of pointless in my view...
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#278
by
Coastal Ron
on 10 May, 2015 03:49
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I've heard production rates for SLS estimated at between one and two a year. That doesn't mean you have to fly them at that rate, though.
Let's say that Congress approves a manned Mars expedition in 2023, after SLS has flown and Orion has flown manned. Let's say the launch date for the expedition is designed for 2030.
That gives everyone 6 years or so to design and test equipment -- DSH designs, ECLSS designs, etc. -- and put together all of the modules needed.
Sure you can store up SLS components and launch them at a fast rate. No doubt someplace can be found to store the SLS inventory. That's not a challenge in my mind.
The challenge is that NASA has to launch something every year to maintain competency in SLS launch operations. So from a practical standpoint if you are building two per year you would launch one and store one.
As to building up 12 SLS worth of hardware in 6 years, that's not possible. And from an operational standpoint that would assume that everything NASA built was going to be launched without extensive testing and validation, and NASA has no reason to take such a risk.
In my mind part of the goal of a DSH would be to validate the hardware we're going to use for going to Mars, and that means spending years operating it in a number of modes.
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#279
by
A_M_Swallow
on 10 May, 2015 03:59
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It was part of the reference of separating cargo and crew, and one of the major reasons why a simple task like delivering cargo to the ISS was made to be done autonomously/robotically rather than rolled into a crewed mission as with shuttle.
And a system like this wouldn't have to be a single launch but the components, I suspect, would have to be much more "plug and play" than ISS construction was. Spending several weeks just to properly assemble it is likely an additional manned launch, not to mention the additional time to then properly outfit the interior. This of course is all additionally complicated by the fact that none of spacecraft available to NASA (Orion, Dragon, CST100) are particularly suited to orbital assembly like shuttle was. So whatever goes up will have to require a minimum of on orbit fitting. So while an inflatable habitat can work well for non-technical habitable space (such as a crew eating/sleeping area) launching one or several and then outfitting them in orbit adds to complexity and safety.
The arms do not have to be on the capsules they could be on the spacestation. A LEO spaceship yard could consist of two modules - a BA330 for the crew plus a work module with several arms and a couple of docking ports. The docking ports would hold the ship being assembled and the cargo vessel(s) bringing up parts.