Quote from: TomH on 03/19/2013 12:39 amThe question remains whether this 8.4 m US is going to be placed in near LEO by the core or whether a significant burn by this stage is required to reach parking orbit.Note that the LEO payload of the Block 1B is quoted as 118 tonnes, more than 20 tonnes higher than Block 1. So evidently the upper stage is at least capable of burning to orbit if the payload on top is heavy enough to warrant it.DIRECT's JUS was far too heavy for the core to put it in orbit even with nothing on top. The result was a larger payload through TLI (in DIRECT's two-launch architecture) than could have been achieved with an in-space stage launched on a J-130.
The question remains whether this 8.4 m US is going to be placed in near LEO by the core or whether a significant burn by this stage is required to reach parking orbit.
.{snip} Which is why I never understood Ares V/LV27.3, the official SLS Block II PoR, or anything that doesn’t allow the core to put everything above it into LEO in a sustainer stage type LV using RS-25’s.
Quote from: Lobo on 03/19/2013 06:06 pm.{snip} Which is why I never understood Ares V/LV27.3, the official SLS Block II PoR, or anything that doesn’t allow the core to put everything above it into LEO in a sustainer stage type LV using RS-25’s.Interesting.Core with (3) RS-25's with 130mt payload on top ( no US ).Boosters to do the extra needed work at launch so the core can take the payload all the way to orbit.Now if the could have gone that way with LRB's then with throttle engines it could have launched less mass to with low enough g's. Possible the boosters could have launched with less engine on them when the stack was launched with less payload mass.So with an 8.4m core could they have been able to make boosters that could have done the job and still fit the MLP and VAB?So for the thread title only.Block I.Block IB ( add RL-10 US )Block IB later with new boosters.Now that is with the thread title, only if we find that we need the 130mt capacity or greater should we go with the new advanced boosters. The best path to 130mt is only if we needed the capacity.Edit:https://info.aiaa.org/Regions/SE/HSV_AIAA/Downloadable%20Items/AIAA-Chilton_18Oct2012_Final2.pdfpage 19.Quote:Advanced boosters require significant funding and ~7 years for development (including 30 month study phase)
There's no question at all that a 130 ton launch vehicle would be more capable than a 70 ton vehicle.The country, as a family, plans on buying a car and an RV, theoretically to go on a long east coast to west coast vacation. Dad sez that they're not going to drive down the east coast from DC to Florida, because they went to Disney World forty years ago. Some of the family members are intent upon getting the biggest RV on the lot; it would require purchasing an F-450 in order to tow it. There's no money for the RV at all, and they'd have to wait for a decade or morre before the F-450 is actually manufactured and ready to sell.Some of the younger members of the family think that the family should just purchase an F-150, which will tow a pretty good sized RV itself, and allow a fair amount of money to be left over to spend when they get to the west coast. The F-150 will be ready to purchase in just a few years, and cost a good bit less. So would the smaller RV.The younger members of the family remember how much fun it was going to Disney World the first time, even tho all they had was Chevy station wagon and a pop up camper. Not only that, but with a new F-150 and a new RV, they could stay in Florida for a while, maybe get jobs picking oranges, and save up the money to pay for the gas to go to the west coast. They could get two vacations that way.The older members of the family insist that the younger members just shut up.
What???
Quote from: Lobo on 03/21/2013 02:50 pmWhat???
There's no question at all that a 130 ton launch vehicle would be more capable than a 70 ton vehicle.
I think the Saturn V was somewhat better than the analogous old Chevy and pop-up camper.
So with an 8.4m core could they have been able to make boosters that could have done the job and still fit the MLP and VAB?
So for the thread title only.Block I.Block IB ( add RL-10 US )Block IB later with new boosters.Now that is with the thread title, only if we find that we need the 130mt capacity or greater should we go with the new advanced boosters. The best path to 130mt is only if we needed the capacity.
Quote from: JohnFornaro on 03/21/2013 12:23 pmThere's no question at all that a 130 ton launch vehicle would be more capable than a 70 ton vehicle.The story about you taking your family camping aside... ;-)I never said they should or needed to make the more capable 130mt vehicle. Just that you could with an ET sized core I think. Which was a reply to Rocketman's post. ...
Quote from: RocketmanUS on 03/21/2013 12:50 amQuote from: Lobo on 03/19/2013 06:06 pm.{snip} Which is why I never understood Ares V/LV27.3, the official SLS Block II PoR, or anything that doesn’t allow the core to put everything above it into LEO in a sustainer stage type LV using RS-25’s.Interesting.Core with (3) RS-25's with 130mt payload on top ( no US ).Boosters to do the extra needed work at launch so the core can take the payload all the way to orbit.Now if the could have gone that way with LRB's then with throttle engines it could have launched less mass to with low enough g's. Possible the boosters could have launched with less engine on them when the stack was launched with less payload mass.So with an 8.4m core could they have been able to make boosters that could have done the job and still fit the MLP and VAB?So for the thread title only.Block I.Block IB ( add RL-10 US )Block IB later with new boosters.Now that is with the thread title, only if we find that we need the 130mt capacity or greater should we go with the new advanced boosters. The best path to 130mt is only if we needed the capacity.Edit:https://info.aiaa.org/Regions/SE/HSV_AIAA/Downloadable%20Items/AIAA-Chilton_18Oct2012_Final2.pdfpage 19.Quote:Advanced boosters require significant funding and ~7 years for development (including 30 month study phase)yea, an ET/Jupiter sized core with three RS-25's can put a payload in orbit, or rather, in disposal orbit.The SLS core is stretched so that it can feed four RS-25's to the same disposale orbit.If an ET/Jupiter sized core were strengthend to support 130mt on top, and have powerful enough boosters, and had three RS-25's, then it should be able to put 130mt into LEO. Liquid boosters help in this as they burn for longer and have better ISP than solids. Three RS-25's produce as much or more thrust and ISP as the five J2's on the S-II stage, and the S-II stage was pushing towards 130mt to LEO. So after booster separation, they should have enough power to push that much payload further up, and then enough ISP later to get to disposal orbit.The boosters might need to be throttled as well as the RS-25's if there's any g-loading issues. But most kerolox boosters no can throttle down to at least 70%.But yea, that configuration could have worked. AJAX was something like that. I can't remember if Downix had 3 or 4 RS-25's on the core, but with 8 Atlas V boosters, I believe he said the core could get 130mt into LEO without needing an upper stage.Two 5.4m wide kerolox boosters with four RD-180's on them each could probably do about the same or a bit better because of the larger single boosters. Although thrust would be about the same as the Dynetics boosters, they have better ISP. So they should be able to do about the same even with the non-stretched core.
If they did go with core to LEO with LRB's at 130mt+-Use the RD-180's for the LRB's.The LRB's could be a 1st stage with the avionics in the 2nd stage.1st stage tanks and engine mount made with specs that America, ESA, and Russia all have the ability to make. Make it a universal 1st stage that could be made in America, ESA, and or Russia. The RD-180's could be made in Russia as is or could expand to America if there is a larger demand for them.America, Russia , and ESA could make their own US for the single stick version. Could possible lower cost for all three partners.If it could be sized right then the core could lift 130mt+ to a given LEO orbit.
Well if the goal is a manned flight to Martian orbit some day, I'd say yes, absolutely we need the new advanced boosters. If however the goal is flinging people over to an EML-2 space station or down to the lunar surface, I'd say the SLS Bloc IB is up to the task. If anyone's ever seen the various imagined Mars Transfer Vehicles thought up by NASA, they all have one thing in common: they're enormous. I believe the last time NASA showed how such a mission might look, it took three Ares V flights just to put the thing into orbit. But at least an MTV would be reusable, which is more than anyone could say for our Apollo hardware. The landers for crew and equipment also have to be quite big, given the mission length, Mars having more gravity than the moon, and the need for both propulsion and aero-braking/heat shield elements. This is why Elon Musk is talking about rockets with a minimum 7 meter core and a capability ranging from 150-200 mt to LEO as being necessary for colonizing Mars.
Nice.Let's go to the Moon, get a job picking oranges, then buy enough gas to drive over to Mars. Sounds like a good plan!
Does that MTV give anyone else ...