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#60
by
Khadgars
on 23 Nov, 2011 03:25
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2. Plain and simple, there is no way to get a 100 ton station to the launch site except by waterway. And there are no 100 ton station production facilities anywhere in the country, much less by any waterways.
BLEO doesn't have 100 ton dry payloads, most of its mass is propellant.
Shuttle, Titan IV, EELV's, ISS, etc all used existing infrastructure
.
Good point Jim. If you don't mind me asking a question, what is the largest payloads that can be supported with existing infrastructure? How difficult would be to increase it?
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#61
by
Jim
on 23 Nov, 2011 03:29
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2. Plain and simple, there is no way to get a 100 ton station to the launch site except by waterway. And there are no 100 ton station production facilities anywhere in the country, much less by any waterways.
BLEO doesn't have 100 ton dry payloads, most of its mass is propellant.
Shuttle, Titan IV, EELV's, ISS, etc all used existing infrastructure.
Good point Jim. If you don't mind me asking a question, what is the largest payloads that can be supported with existing infrastructure? How difficult would be to increase it?
[/quote]
With no assembly at the launch site, Shuttle payload bay (C-5C transportable).
Using foreign aircraft (Dreamlifter is not available for hire), Beluga or An-124 might get you something larger, but a new container would be required and then there is getting that new container from the factory to the airport. Then there is the matter of test facilities, thermovac chambers, acoustic cells, vibe tables, etc.
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#62
by
sdsds
on 23 Nov, 2011 03:32
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For those who question the need to compete the advanced boosters, but are interested in considering massive payloads, it might be useful to look at the limitation imposed by the transportation infrastructure between the VAB and the pad. The mass of the propellant that powers liquid boosters wouldn't be carried by the crawler-transporter; presumably at least some of that mass budget would then available for the payload.
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#63
by
Patchouli
on 23 Nov, 2011 03:49
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For those who question the need to compete the advanced boosters, but are interested in considering massive payloads, it might be useful to look at the limitation imposed by the transportation infrastructure between the VAB and the pad. The mass of the propellant that powers liquid boosters wouldn't be carried by the crawler-transporter; presumably at least some of that mass budget would then available for the payload.
That does seem to be an over looked problem they'll have to address.
How will a large lander find it's way to the VAB how will large aeroshell sections be handled?
The SLS design team needs to look into that and the infrastructure costs should be weighed with an SHLV.
A Mars Hab is close to the dry masses being discussed here and probably a bigger pain to transport due it possibly being a wide squat shape.
Air transport probably will be out of the question.
It is not insurmountable they did it once in 1973 though Skylab was only 6.6M wide.
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#64
by
Robotbeat
on 23 Nov, 2011 03:52
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No, a Mars Hab wouldn't have a dry weight of anywhere near 100 dry tons. We don't even have the EDL technology (even when scaled up to larger fairing sizes) to safely land something much greater than a few tons, let alone 100 dry tons!!! It'd plow into the Martian soil. No, a Mars Hab will have to be much less massive than that.
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#65
by
Khadgars
on 23 Nov, 2011 03:53
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With no assembly at the launch site, Shuttle payload bay (C-5C transportable).
Using foreign aircraft (Dreamlifter is not available for hire), Beluga or An-124 might get you something larger, but a new container would be required and then there is getting that new container from the factory to the airport. Then there is the matter of test facilities, thermovac chambers, acoustic cells, vibe tables, etc.
Thanks. None of those upgrades have even been considered, seems like we'll be at Shuttle payload for the foreseeable future.
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#66
by
Patchouli
on 23 Nov, 2011 03:54
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No, a Mars Hab wouldn't have a dry weight of anywhere near 100 tons. We don't even have the EDL technology (even when scaled up to larger fairing sizes) to safely land something much greater than a few tons, let alone 100 tons!!! It'd plow into the Martian soil. No, a Mars Hab will have to be much less massive than that.
Landing weight for a hab often can be around 60 mT entry which is close to 70mT being discussed here.
http://atomicrockets.posterous.com/mars-design-reference-mission-10-1993Zurbin's Mars Direct got the landed mass down to around 30mT though NASA thought it was an overly optimistic number.
What shows up for assembly at the processing facility may be only 20 to 40 mT until the equipment is loaded but the same could be said for the Station module being discussed here.
A lot of the mass is not the hull but all the stuff that goes into it.
Another thing I just realised that I missed in early posts is the launch weight of a modern Skylab type module need not be as much even if it's significantly larger as Skylab was launched fully stocked and outfitted.
I gave it some thought and an ISS II module could be launched bare bones and outfitted on orbit.
Though what they launch will probably be driven by what the LV they have available can do even with the above ground transport and processing issues.
Skylab was to launch on two IBs but ended up on the INT-21 when there was a spare Saturn V.
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#67
by
PeterAlt
on 23 Nov, 2011 09:13
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A successor to ISS will not break the banks (or NASA's budget) like ISS almost did. Here are some obvious key points that should keep the cost of such a successor inline:
- Lower R&D cost. The life support systems, Common Berthing Mechinism design, the gyroscopes, the solar arrays, trusses, etc. have already been designed (for ISS), so much of that could be reused. Also, systems being designed for SLS might also find a use.
- 70 plus ton modules can carry pretty much a mostly completed station. This means less launches, less modules to build, less redundancy.
- Dual use / Dual support / Dual purpose Exploration habitat modules. ISS-2 should be designed from the get-go to support Exploration missions as its primary mission.
- By this time, the commercial space program in LEO should be beginning to blossom. Additional services, capacity, and capabilities could be purchased from the commercial providers, lowering costs.
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#68
by
Jim
on 23 Nov, 2011 14:45
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- Lower R&D cost. The life support systems, Common Berthing Mechinism design, the gyroscopes, the solar arrays, trusses, etc. have already been designed (for ISS), so much of that could be reused.
Not true, they would have been produced over 20 years ago. The people and facilities and subcontractors would be gone.
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#69
by
Jim
on 23 Nov, 2011 14:46
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- 70 plus ton modules can carry pretty much a mostly completed station. This means less launches, less modules to build, less redundancy.
See my other posts, they will not be cheaper
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#70
by
clongton
on 24 Nov, 2011 02:33
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There will be no money for NASA space stations
It's nice to know that "Back to the Future" was not just a scifi film and that people can actually jump into the future, read the paper and then come back to us and tell us what the future actually holds for us.
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#71
by
hop
on 24 Nov, 2011 02:55
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There will be no money for NASA space stations
It's nice to know that "Back to the Future" was not just a scifi film and that people can actually jump into the future, read the paper and then come back to us and tell us what the future actually holds for us.
You know, what I wrote was short enough that you could have kept the whole context:
There will be no money for NASA space stations, or much of anything else if we actually to the point of using SLS for exploration. (edit: based on historical funding levels...)
Should be pretty clear I wasn't intending that as an absolute statement. It's conditional on SLS / BEO actually happening, and NASA funding following historical tends.
I don't see any reason beyond wishful thinking to believe NASA will get massive budget increases, but I could certainly be wrong...
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#72
by
Proponent
on 24 Nov, 2011 03:48
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Skylab was to launch on two IBs but ended up on the INT-21 when there was a spare Saturn V.
Actually, it was more that the Saturn V allowed Skylab to be heavier and fully fitted out from the beginning, and therefore more capable. Turning the wet S-IVB into a workshop was also a little more difficult than originally anticipated. See
Skylab: A Chronology, particularly the
entry for 21 May 1969.
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#73
by
Patchouli
on 26 Nov, 2011 19:21
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Skylab was to launch on two IBs but ended up on the INT-21 when there was a spare Saturn V.
Actually, it was more that the Saturn V allowed Skylab to be heavier and fully fitted out from the beginning, and therefore more capable. Turning the wet S-IVB into a workshop was also a little more difficult than originally anticipated. See Skylab: A Chronology, particularly the entry for 21 May 1969.
Yah I'm not sure if they could have pulled off the wet workshop in 1973 you'd almost need the space shuttle for that kind of orbital refit.
Plus could they make everything able to fit though the Apollo docking adapter?
It seems over all the change was the right one and maybe even saved the Skylab program.
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#74
by
Gregori
on 26 Nov, 2011 20:18
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Seems kinda hokey. The heaviest US modules of the ISS only weigh about 14 tons. They weren't designed with the intent of maxing out the payload capability of the launcher.
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#75
by
Jim
on 26 Nov, 2011 22:39
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.
Skylab was to launch on two IBs but ended up on the INT-21 when there was a spare Saturn V.
Skylab was launched on a two stage Saturn V and not an INT-21. INT-21 had other mods such as moving the IU to top of the second stage
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#76
by
arkaska
on 28 Nov, 2011 11:10
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Seems kinda hokey. The heaviest US modules of the ISS only weigh about 14 tons. They weren't designed with the intent of maxing out the payload capability of the launcher.
That is the module itself not including hardware to outfit the module. They were launched with as much internal hardware as possible.
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#77
by
spectre9
on 28 Nov, 2011 11:32
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Since this thread is about the ISS maybe international partners would want to build a huge module?
NASA pays for the SLS to launch it and gets full use of it in orbit.
You will only need the one to make quite a nice sized space station. The rest could be made out of smaller modules or inflatables.
I think many countries would love the opportunity to put more astronauts in orbit on a more consistant basis.
Now Satoshi is back on Earth (miss him already) JAXA has that big module with nobody up there doing research. The stuff he was doing related to cancer did sound important.
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#78
by
Ronsmytheiii
on 28 Nov, 2011 13:01
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Skylab was to launch on two IBs but ended up on the INT-21 when there was a spare Saturn V.
Minor nitpicking, but Skylab was launched on a two stage Saturn V rather than INT-21, as the avionics were still on the third stage (Skylab) and not the S-II.
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#79
by
Jim
on 28 Nov, 2011 13:16
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Now Satoshi is back on Earth (miss him already) JAXA has that big module with nobody up there doing research. The stuff he was doing related to cancer did sound important.
The remaining astronauts take over for him. Just because an international partner doesn't have an astronaut onboard doesn't mean research in their modules stop.
