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#240
by
redliox
on 03 May, 2015 10:41
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When I look at the Mars Transit Habitat, Professor Farnsworth in my head mutters
"Sweet Zombie Geebus!" It looks like a propellant parade! But getting serious, I have to admit as unwieldy as the setup looks, that could be a viable way to get to Mars. I can only presume by storable they imply hypergollic fuels, otherwise I would hope there could be a way to condense that chain of stages to simplify assembly. Not my first choice, but the roominess of the Hab would prove extremely useful.
My first choice of configurations favors the SLS-derivatives. They are decidedly spacious and robust. If you look at the chart on mass and volume, it is quick to see the vast differences in habitat space. Both the Mir and ISS' modules were limited by the size of their launchers; obviously the SLS lifts that limit vastly.
I'd love to see the C-2 option utilized - the best you can get from a single-piece space station. I wouldn't be against adding a second module, but with what an SLS can bring in one stroke that is purely optional.
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#241
by
TrevorMonty
on 03 May, 2015 17:54
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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.
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#242
by
BrightLight
on 03 May, 2015 18:15
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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.
But would the "commercial" habitat be cheaper and/or more capable. For instance the Orbital Cygnus model would need to be assembled in orbit, each module would require a bus or space tug - will it be less expensive? will it supply the right environment? I agree that a commercial hab without government requirements should be less expensive but if its built to NASA/government specifications, the cost will go up.
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#243
by
TrevorMonty
on 03 May, 2015 21:42
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NASA are trying to make this habitat module multipurpose.
1) EAM to give extend Orion mission live from 21 to 60days. In this situation Orion can provide all the live support, EAM just gives extra room for living, storage for supplies, waste and exercise equipment. The Cygnus could almost could do this as is.
2) DSH would be a small spacestation with ECLSS. One module maybe able contain all the essential equipment with additional modules to add extra space for accommodation, exercise, airlock/docking node and labs.
3) Surface habitat, moon/mars/phobos. This is on NASA wish list for now but it will be needed eventually. Smaller modules work better here as one class of lander can be used for habitat, cargo and crew. Large habitats would require development of a expensive dedicated large lander.
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#244
by
Coastal Ron
on 03 May, 2015 22:19
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My first choice of configurations favors the SLS-derivatives. They are decidedly spacious and robust. If you look at the chart on mass and volume, it is quick to see the vast differences in habitat space. Both the Mir and ISS' modules were limited by the size of their launchers; obviously the SLS lifts that limit vastly.
I've heard comments about the size of the ISS modules before, but as I watch ISS crew doing daily work on NASA TV I don't see that they are space constrained. So I'm not sure that a larger diameter volume really addresses a current constraint.
That said, it is inevitable that we will build bigger in space, but I'm not sure aluminum enclosures are the preferred outer hull materials. NASA has a story about "
Plastic Spaceships", which pretty much shows why they are interested in inflatables. However inflatables don't see to be a part of the current exploration architectures, like the one you reference, which is weird. Why are they proposing aluminum crew modules when they know they are not as safe (or roomy) as inflatable modules?
I'd love to see the C-2 option utilized - the best you can get from a single-piece space station.
Not to debate it here, but it seems there are two camps on that topic:
- Those that want to pile everything into one vehicle and hope it's not lost on launch.
- Those that want to use modular/commoditized construction (like the ISS) so that a launch loss is more tolerable.
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#245
by
redliox
on 03 May, 2015 22:40
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I'd love to see the C-2 option utilized - the best you can get from a single-piece space station.
Not to debate it here, but it seems there are two camps on that topic:
- Those that want to pile everything into one vehicle and hope it's not lost on launch.
- Those that want to use modular/commoditized construction (like the ISS) so that a launch loss is more tolerable.
There's always a chance of a launch disaster, but I think the difference is in long-term cost. Skylab was cobbled together, but it also was made in an era where the shuttle hadn't materialized and was a success despite the initial damage. The ISS, while more extensive and indeed proving to be a decent science platform, took 15 years and over two dozen shuttle flights...with each shuttle fight often being a half-billion dollars. It wasn't easy or cheap to put the ISS together, and it's only been for the last ~5 years it's been performing science at full capacity.
Point is, and not to elaborate on this argument...is it will come down to cost. One launch, even with a juggernaut space module, is cheaper than five. That will be the bottom line the OBM and Congress eyes for approval, single-module or mult-module.
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#246
by
redliox
on 03 May, 2015 22:46
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3) Surface habitat, moon/mars/phobos. This is on NASA wish list for now but it will be needed eventually. Smaller modules work better here as one class of lander can be used for habitat, cargo and crew. Large habitats would require development of a expensive dedicated large lander.
The Mars Transit Hab using the large SLS-derived module certainly should be adequate for supporting both orbital operations and Deimos/Phobos expeditions, moreso on the later if the flexcraft is included. That essentially just means tweaking it later to make a lander; likewise I could see the Orion capsule (the cabin at least) getting tweaked to serve as a Mars Ascent Stage.
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#247
by
Coastal Ron
on 03 May, 2015 23:17
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There's always a chance of a launch disaster, but I think the difference is in long-term cost.
In a way evolution takes care of this, since architectures that are too "fragile" (for one reason or another) will be more likely to not be reused again.
Skylab was cobbled together, but it also was made in an era where the shuttle hadn't materialized and was a success despite the initial damage. The ISS...
Skylab and the ISS cannot be compared for costs or capabilities. For instance, Skylab used excess Apollo hardware so at least part of it's cost was already paid for by the Moon program. For the ISS, NASA had to use the Shuttle for political reasons - it was operational and had a lot of political support. But we all know it was the most expensive option for moving mass to LEO, so cost at the time was not a real constraint.
The ISS, while more extensive and indeed proving to be a decent science platform, took 15 years and over two dozen shuttle flights...
And the ISS is 6X the mass of Skylab with 3X the pressurized volume. Skylab was a simple prototype, so making one-to-one comparisons is impossible.
It wasn't easy or cheap to put the ISS together...
Actually the ISS went together pretty easily, and it's able to reconfigure itself only because it is modular. A single-hull future station would not be as flexible.
...and it's only been for the last ~5 years it's been performing science at full capacity.
That's because of politics, not because of something inherent in the design. Congress cancelled the X-38 Crew Return Vehicle, which would have allowed us to fully staff the ISS far earlier than by using the Commercial Crew program.
Point is, and not to elaborate on this argument...is it will come down to cost. One launch, even with a juggernaut space module, is cheaper than five. That will be the bottom line the OBM and Congress eyes for approval, single-module or mult-module.
I would certainly hope that cost is allowed to be a primary consideration, and not a secondary one. I say that because once you have decided to use specific transportation elements you start locking yourself into certain cost structures. My hope would be that all are given full consideration before any decisions are made.
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#248
by
BrightLight
on 04 May, 2015 03:29
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From Coastal Ron
I would certainly hope that cost is allowed to be a primary consideration, and not a secondary one. I say that because once you have decided to use specific transportation elements you start locking yourself into certain cost structures. My hope would be that all are given full consideration before any decisions are made.
I also would hope that cost is a primary factor - I see the SLS derived module as being favored by NASA with the Bigelow BA330 as an alternate. I have a jaded opinion about how congress picks projects but I will leave that out.
One argument that has been used is that the SLS is already under construction so a barrel section would be something that can be reproduced (personal communication).
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#249
by
Burninate
on 04 May, 2015 06:52
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From Coastal Ron
I would certainly hope that cost is allowed to be a primary consideration, and not a secondary one. I say that because once you have decided to use specific transportation elements you start locking yourself into certain cost structures. My hope would be that all are given full consideration before any decisions are made.
I also would hope that cost is a primary factor - I see the SLS derived module as being favored by NASA with the Bigelow BA330 as an alternate. I have a jaded opinion about how congress picks projects but I will leave that out.
One argument that has been used is that the SLS is already under construction so a barrel section would be something that can be reproduced (personal communication).
Wouldn't the direct analog for an SLS-tank derived module be a BA-2100?
Hopefully there will be BA330's in orbit before SLS Block 1B, and possibly even before the single unit of SLS Block 1.
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#250
by
redliox
on 04 May, 2015 07:48
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From Coastal Ron
I would certainly hope that cost is allowed to be a primary consideration, and not a secondary one. I say that because once you have decided to use specific transportation elements you start locking yourself into certain cost structures. My hope would be that all are given full consideration before any decisions are made.
I also would hope that cost is a primary factor - I see the SLS derived module as being favored by NASA with the Bigelow BA330 as an alternate. I have a jaded opinion about how congress picks projects but I will leave that out.
One argument that has been used is that the SLS is already under construction so a barrel section would be something that can be reproduced (personal communication).
Wouldn't the direct analog for an SLS-tank derived module be a BA-2100?
Hopefully there will be BA330's in orbit before SLS Block 1B, and possibly even before the single unit of SLS Block 1.
My compromise would be launching the SLS-module and then docking a BA-2100 to it. ISS on steroids anyone?
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#251
by
TrevorMonty
on 04 May, 2015 19:38
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In my quest to find out how new Hab systems will function at EM1/2 and Mars I have been periodically in contact with some NASA folks.
From a MSFC source:
Work is still continuing with it's development. The flooring system was installed at the end of last FY. The walls for the lower floor layout are built with minimal low fidelity systems installed. Due to some redirection, the funding and manpower is being reduced. However, we are still working to support this effort. There are some other trade studying occurring to use smaller modules, but they will take multiple launched to complete."
Also are attached two new pictures of the SLS derived hab simulator. I suspect these trades are between three competing frameworks - A commercial modular system with GFE internal ECLSS, some form of ISS module package and the SLS derived system.
What does GFE stand for?.
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#252
by
BrightLight
on 04 May, 2015 23:03
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In my quest to find out how new Hab systems will function at EM1/2 and Mars I have been periodically in contact with some NASA folks.
From a MSFC source:
Work is still continuing with it's development. The flooring system was installed at the end of last FY. The walls for the lower floor layout are built with minimal low fidelity systems installed. Due to some redirection, the funding and manpower is being reduced. However, we are still working to support this effort. There are some other trade studying occurring to use smaller modules, but they will take multiple launched to complete."
Also are attached two new pictures of the SLS derived hab simulator. I suspect these trades are between three competing frameworks - A commercial modular system with GFE internal ECLSS, some form of ISS module package and the SLS derived system.
What does GFE stand for?.
Government furnished equipment
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#253
by
Ronpur50
on 06 May, 2015 20:12
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One of the interesting components of the analysis shown in Figure 12 of the paper is that the SLS derived habitat systems has less mass than the ISS modular designs - interesting.
also
The SLS designs are more capable multi-mission systems - is this the proverbial "thumb on the scale" or is this a result of better design?. All of these designs appear to be much larger than the commercial concepts outlined in the program described in http://aviationweek.com/Habitats
Attached is the Mars stack with the SLS derived Habitat from "Habitat Concepts for Deep Space Exploration"
Would this HAB be reusable for more than one flight? Obviously, new tanks would be added and logistics needed.
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#254
by
Endeavour_01
on 07 May, 2015 00:55
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One of the interesting components of the analysis shown in Figure 12 of the paper is that the SLS derived habitat systems has less mass than the ISS modular designs - interesting.
also
The SLS designs are more capable multi-mission systems - is this the proverbial "thumb on the scale" or is this a result of better design?. All of these designs appear to be much larger than the commercial concepts outlined in the program described in http://aviationweek.com/Habitats
Attached is the Mars stack with the SLS derived Habitat from "Habitat Concepts for Deep Space Exploration"
Would this HAB be reusable for more than one flight? Obviously, new tanks would be added and logistics needed.
The way I read it the SLS derived Mars habitat would be reusable. It would just need to be resupplied after each mission.
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. Also the economy of scale for SLS will benefit greatly and our investment in developing SLS will pay off more.
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#255
by
Coastal Ron
on 07 May, 2015 01:17
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The way I read it the SLS derived Mars habitat would be reusable. It would just need to be resupplied after each mission.
Going forward all major hardware should be reusable. We're either making plans to stay in space, or we shouldn't be going...
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.
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.
If SLS-derived space station modules are committed to, then because they are so large and complex internally they could take too many years to build and test to fill in the launch gap that is looming.
Which is yet another advantage proven ISS modules have over SLS-sized ones. 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.
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#256
by
newpylong
on 07 May, 2015 15:15
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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.
Of course none of this is in the 2 year budget, nor will it be until ISS operations begin to wind down. It only took Skylab 5 years to be built - and that included two years of trades related to dry/wet workshops. Don't expect development and construction to be funded right now when it won't be needed for a decade.
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#257
by
Coastal Ron
on 07 May, 2015 21:29
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Of course none of this is in the 2 year budget, nor will it be until ISS operations begin to wind down.
You make it sound like it's a good idea not to start work on payloads for the SLS. I'm not sure you understand the ramifications of the SLS not flying every year once it is deemed operational in 2022. If the SLS isn't needed for anything, then why is it being built?
It only took Skylab 5 years to be built - and that included two years of trades related to dry/wet workshops.
The new standard to beat is ISS modules, not Skylab. As far as capabilities/kg, Skylab was pretty low on the scale.
Besides, if all anyone cares about is a giant empty aluminum can with a few fixed stations, and volumes of open space to run around in like a giant hamster wheel, then we'd use inflatable habitats.
But if an SLS-derived station module is going to be utilized to the degree that that ISS modules are used, then that's going to take a while to design and build. Especially for the first one.
Don't expect development and construction to be funded right now when it won't be needed for a decade.
You seem to favor mothballing the SLS for a decade or so until there is enough money to support the production of payloads it's supposed to launch no-less-than every 12 months. How interesting...
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#258
by
JazzFan
on 07 May, 2015 23:06
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Of course none of this is in the 2 year budget, nor will it be until ISS operations begin to wind down.
The new standard to beat is ISS modules, not Skylab. As far as capabilities/kg, Skylab was pretty low on the scale.
Besides, if all anyone cares about is a giant empty aluminum can with a few fixed stations, and volumes of open space to run around in like a giant hamster wheel, then we'd use inflatable habitats.
But if an SLS-derived station module is going to be utilized to the degree that that ISS modules are used, then that's going to take a while to design and build. Especially for the first one.
There have been plenty of advances since NASA's first successful endeavor at a space station. I see no need for another large empty can to just prove a point. There are now plenty of lessons learned and current designs and equipment which can be utilized to maximize functionality within the space provided.
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#259
by
newpylong
on 08 May, 2015 11:01
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Of course none of this is in the 2 year budget, nor will it be until ISS operations begin to wind down.
You make it sound like it's a good idea not to start work on payloads for the SLS. I'm not sure you understand the ramifications of the SLS not flying every year once it is deemed operational in 2022. If the SLS isn't needed for anything, then why is it being built?
It only took Skylab 5 years to be built - and that included two years of trades related to dry/wet workshops.
The new standard to beat is ISS modules, not Skylab. As far as capabilities/kg, Skylab was pretty low on the scale.
Besides, if all anyone cares about is a giant empty aluminum can with a few fixed stations, and volumes of open space to run around in like a giant hamster wheel, then we'd use inflatable habitats.
But if an SLS-derived station module is going to be utilized to the degree that that ISS modules are used, then that's going to take a while to design and build. Especially for the first one.
Don't expect development and construction to be funded right now when it won't be needed for a decade.
You seem to favor mothballing the SLS for a decade or so until there is enough money to support the production of payloads it's supposed to launch no-less-than every 12 months. How interesting...
I insinuated none of what you wrote. Putting words in people's mouths is a bad habit to have.
