Quote from: RonM on 10/02/2015 09:16 pmNASA has stated they won't build another LEO space station.I agree that powerful people (including I think NASA Administrator Charlie Bolden) say that, and it reflects the view of the President of the United States. But in 2020 I do not believe Charlie Bolden will be NASA Administrator, and I am 100% certain President Obama will no longer occupy the Oval Office!
NASA has stated they won't build another LEO space station.
Quote from: robertross on 10/02/2015 10:48 pmQuote from: jongoff on 10/01/2015 11:04 pmAlso, IIRC doesn't the quantity-distance rules on the SRBs mean they are only allowed to have two SLS vehicles in the VAB at one time, or am I misremembering that detail?~JonSomewhere on L2 there was nice overview of the VAB facility and the maximum number of SRB segments allowed in there. I thought it was 10 segments total.Ok, so I'm not misremembering things. So that would prevent having more than two SLS's in the building at any given time. One of the joys of big SRBs...~Jon
Quote from: jongoff on 10/01/2015 11:04 pmAlso, IIRC doesn't the quantity-distance rules on the SRBs mean they are only allowed to have two SLS vehicles in the VAB at one time, or am I misremembering that detail?~JonSomewhere on L2 there was nice overview of the VAB facility and the maximum number of SRB segments allowed in there. I thought it was 10 segments total.
Also, IIRC doesn't the quantity-distance rules on the SRBs mean they are only allowed to have two SLS vehicles in the VAB at one time, or am I misremembering that detail?~Jon
EDIT: After double-checking a bit, it seems my memory was correct; from what we know, BA-2100 is not close to being light enough for the 53-tonne Falcon Heavy to lift it. Some sort of upgrade would be required.
Quote from: 93143 on 10/03/2015 04:13 amEDIT: After double-checking a bit, it seems my memory was correct; from what we know, BA-2100 is not close to being light enough for the 53-tonne Falcon Heavy to lift it. Some sort of upgrade would be required.Well talk with Bigelow about that, but if the moniker "BA-2100" is what bothers you, change the name to BA-2000, or BA-1782. Remember it doesn't have a firm requirement - it's notional.
Quote from: TomH on 10/02/2015 08:20 pmFeeling a bit sensitive today? Where did all that come from?Ha! You should have seen my post before I self-censored it. LOL.So, now the consensus is that there will only be one ML, thus the minimum time between SLS launches will be however long it takes to stack one up in the VAB. Does anyone have an idea about how long that may be?Which then brings us back to the Mars mission proposals mentioned in the recent article, as Khadgars kindly pointed out. One proposal has two SLS launches of equipment to Mars in 2034, 2035, and 2036. (Five landers and the EOI stage.) I'm no orbital expert, but I thought that Mars missions were normally spaced out every two years due to the relationship between Earth's and Mars' orbits. Is it possible to launch large payloads to Mars in the "off" years?And, going back to the minimum time between SLS launches, how large is the launch window for Mars missions in the "on" years? Is it possible that a delay in the stacking of the second SLS in a sequence would cause it to miss the launch window?Thanks.
Feeling a bit sensitive today? Where did all that come from?
Quote from: sdsds on 10/03/2015 04:24 amQuote from: RonM on 10/02/2015 09:16 pmNASA has stated they won't build another LEO space station.I agree that powerful people [...] say thatIt reflects the view of many at NASA
Quote from: RonM on 10/02/2015 09:16 pmNASA has stated they won't build another LEO space station.I agree that powerful people [...] say that
It is speculated that by 2024 SpaceX would have its BFR flying but maybe not the MCT so they could use that vehicle with an interim expendable US to launch SLS sized cargo (15m diameter and 100mt+ weight payloads).
Quote from: Proponent on 09/27/2015 11:31 amTo exactly which document do you refer? If to "ESD Integration; Budget Availability Scenarios" dated 19 August 2011 (attached to this post), where does the statement appear?Right below every sand chart, it says the following:FY11: 21st CGS = CxP GO; MPCV = CxP Orion + EVA + MO; SLS =Ares I FS (Booster / Avionics), Ares I J-2X (US Engine), SSP SSME (Core Engine), SSP ET (Core Stage), Ares I PM / VI / S&MA / FITO (Prog Integ)I may have overstated the clarity of the statement somewhat; how would you interpret this?
To exactly which document do you refer? If to "ESD Integration; Budget Availability Scenarios" dated 19 August 2011 (attached to this post), where does the statement appear?
For example, while SLS's core stage superficially looks just like a Space Shuttle ET, it is in fact quite different, if for no other reason than the very different loads it bears.
Booz Allen Hamilton produced a contemporaneous critique (summary attached, for those who may not have seen it earlier) which described the cost savings NASA assumed for Orion/SLS as poorly justified.
Regardless of whether the criticism was correct, it does show that the ESD budget scenarios assumed future cost savings and were not based solely on Shuttle/Ares costs.
If they are going to build a station, I agree it should be at L1 or L2. I also wish they would build a rotating station at least with moon gravity. I would really like them to build one based on Mars gravity, to test long term effects of Martian gravity on humans.
The L point station should also be modular enough to have replacements periodically for continuous operations. It should also be able to expand into a fuel depot for Mars transits, and a warehouse type depot for Mars cargo departures.
All this can be future planned 100 ton launches from the SLS, to minimize in space assembly. Smaller components could be launched using existing launchers, FH, and Vulcan. Until SpaceX gets the BFR going.
No justification has yet been presented for "the ESD Integration estimates were based directly on Shuttle and Ares."
Thanks to BAH, we know that NASA built to-be-realized cost efficiencies into at least some of its scenarios.
There is a theoretical possibility that NASA applied those efficiencies only to Case 1 and not to other cases, but that's rather unlikely and would be positively disingenuous.
You infer that inflation has been built into ESD's estimates. How do you do that? With budgets generally flat-lining, except for an explicit in-space-elements "wedge" in later years, it looks to me like everything is priced in FY 2012 dollars.
"RY" might mean "real": I suppose to people who spend their workdays with terms like "FY", "CY" and "TY, " a construction like "RY" might seem reasonable.
I'm not aware of any design for a rotating station that requires 100 ton modular components (i.e. SLS), or even 50 ton components (i.e. FH).
And using Earth analogies, we build the largest buildings in the world using the same sized semi-trailer trucks that we use for much building small houses, so I think $/kg will be the more important metric for determining which type of transportation is used, not size.
Quote from: Coastal Ron on 10/14/2015 12:10 amI'm not aware of any design for a rotating station that requires 100 ton modular components (i.e. SLS), or even 50 ton components (i.e. FH).Those are LEO masses. For an L-point station you'd be looking at much smaller units, unless you postulate additional propulsion technologies (depots, large electric tugs).
QuoteAnd using Earth analogies, we build the largest buildings in the world using the same sized semi-trailer trucks that we use for much building small houses, so I think $/kg will be the more important metric for determining which type of transportation is used, not size.http://www.jbis.org.uk/paper.php?p=2003.56.362
Quote from: 93143 on 10/14/2015 06:44 amQuote from: Coastal Ron on 10/14/2015 12:10 amI'm not aware of any design for a rotating station that requires 100 ton modular components (i.e. SLS), or even 50 ton components (i.e. FH).Those are LEO masses. For an L-point station you'd be looking at much smaller units, unless you postulate additional propulsion technologies (depots, large electric tugs).If we're moving construction mass beyond LEO, then using SEP tugs or some other form of more efficient transportation would be used - we don't have to be constrained by the limitations of an upper stage.QuoteQuoteAnd using Earth analogies, we build the largest buildings in the world using the same sized semi-trailer trucks that we use for much building small houses, so I think $/kg will be the more important metric for determining which type of transportation is used, not size.http://www.jbis.org.uk/paper.php?p=2003.56.362I'm not paying money for some 12 year old random study to try and figure out whether you have a point or not.
@oldAtlas_Eguy you do realize that a SLS that can put 100mt in LEO is a Block 2 variant. We only have the Block-1 and maybe the Block-1B available for the foreseeable future. I am guessing the SLS can get roughly 50 or 60 mt up to LEO with a non-Block-2 variant.
It could be manned continuously to monitor the fuels, and make maybe have robotic arms for helping SEP tugs refuel, or various vehicles to dock and refuel for out flights.
Quote from: Zed_Noir on 10/14/2015 05:04 pm@oldAtlas_Eguy you do realize that a SLS that can put 100mt in LEO is a Block 2 variant. We only have the Block-1 and maybe the Block-1B available for the foreseeable future. I am guessing the SLS can get roughly 50 or 60 mt up to LEO with a non-Block-2 variant.No, Block-2 is 130mt. Block-1 is basically the development version. Block-1B is the future workhorse variant, and it will put more than 100mt into LEO.Mark S.