Quote from: Robotbeat on 09/11/2017 10:56 pmOkay, but that's just engineering. Nothing fundamentally challenging about that part of it.In exactly the same way that FH was just hooking 3 F9's together?
Okay, but that's just engineering. Nothing fundamentally challenging about that part of it.
Quote from: john smith 19 on 09/12/2017 06:59 pmQuote from: Robotbeat on 09/11/2017 10:56 pmOkay, but that's just engineering. Nothing fundamentally challenging about that part of it.In exactly the same way that FH was just hooking 3 F9's together?Whole point of that clustering is it WOULDN'T require even a concerted reengineering effort of the components. They were wrong. With ITS, that will be needed no matter what and there's no fooling themselves about it so they can plan from the start.ITS WILL have major challenges. They're not going to necessarily be mundane and easily foreseeable ones like that.Let's try to ask insightful questions, like how they hope to deal with center of mass during entry, etc.
Lack of LAS might be an issue with the original ITS design carrying 100 people on colonization flights, but it doesn't have to be an issue for ITSy conducting exploration missions. With a small crew they can launch later in a Dragon.
Quote from: RonM on 09/13/2017 03:16 amLack of LAS might be an issue with the original ITS design carrying 100 people on colonization flights, but it doesn't have to be an issue for ITSy conducting exploration missions. With a small crew they can launch later in a Dragon.And this begs the question, how useful is a LAS when departing the surface of Mars?
One short-ish cut available to an over sized single body booster, is to just not sharpen the virtual pencil too much. Start with the least amount of new technology (alloy not carbon) and make it heavier than optimum.Build, fly, analyze, repeat.
Pretty sure no one will be proposing a three core vehicle at the IAC
Whole point of that clustering is it WOULDN'T require even a concerted reengineering effort of the components. They were wrong. With ITS, that will be needed no matter what and there's no fooling themselves about it so they can plan from the start.ITS WILL have major challenges. They're not going to necessarily be mundane and easily foreseeable ones like that.
Let's try to ask insightful questions, like how they hope to deal with center of mass during entry, etc.
We've been imagining on related threads a vehicle - first stage: booster and second stage: spacecraft - up to 9 meters in diameter. Such a launcher would be fully reusable with a big cluster of 'subscale Version 1.0' Raptors in the first stage (not 42x biguns) and a small cluster of subscale Raptors in the spacecraft. A roughly two-thirds scale ITS to prove out the basic concept without going straight to the gargantuan 42-engine behemoth with the 42 Raptors. We can assume a targeted liftoff thrust of probably no more than 11 or 12 million pounds; to keep within the Pad 39A limits.We'll have to see what happens in due course. It will be very interesting - a vehicle that could have great utility and capability. We'll just have to be patient...
IMO, the larger Raptor engine will be on the stand this year (next 12 months) and be used to power the booster. If the full spaceship is built for the 9m, which I think likely, it may use the smaller version, as may a conventional upper stage use maybe 3 of these engines. 12Mlbs lift-off thrust is almost a given...I think the planned use and lifetime of this ITSy will be most interesting aspect of IAC 2017 -- when will it be built and when will it head for Mars. I don't see this as merely a prototyping effort for the BFR. It is the BFR for next 10+ years -- the World's BFR.
Flight qualifying the subscale Raptor would enable them to fly a methane vehicle in 2020. Later they can change the thrust structure and stretch the tanks going for a bigger even more capable vehicle.
Quote from: AncientU on 09/13/2017 01:05 pmIMO, the larger Raptor engine will be on the stand this year (next 12 months) and be used to power the booster. If the full spaceship is built for the 9m, which I think likely, it may use the smaller version, as may a conventional upper stage use maybe 3 of these engines. 12Mlbs lift-off thrust is almost a given...I think the planned use and lifetime of this ITSy will be most interesting aspect of IAC 2017 -- when will it be built and when will it head for Mars. I don't see this as merely a prototyping effort for the BFR. It is the BFR for next 10+ years -- the World's BFR.Just to clarify, do you mean the original ITS Spaceship being built as the 2nd stage for the mini-ITS first stage? Meaning that only the first stage is downscaled to 9m? How would that work with the factory constraints that limit the first stage to a 9m diameter? Surely both stages need to be downscaled.
Quote from: guckyfan on 09/13/2017 01:40 pmFlight qualifying the subscale Raptor would enable them to fly a methane vehicle in 2020. Later they can change the thrust structure and stretch the tanks going for a bigger even more capable vehicle.So the redesign of the vehicle for 3x raptor is not VERY hard?How about the factory line for subscale first then full scale? Is there a use for a subscale that will exist after full scale is available?Thereby justifying the expense.
Quote from: M.E.T. on 09/13/2017 01:10 pmQuote from: AncientU on 09/13/2017 01:05 pmIMO, the larger Raptor engine will be on the stand this year (next 12 months) and be used to power the booster. If the full spaceship is built for the 9m, which I think likely, it may use the smaller version, as may a conventional upper stage use maybe 3 of these engines. 12Mlbs lift-off thrust is almost a given...I think the planned use and lifetime of this ITSy will be most interesting aspect of IAC 2017 -- when will it be built and when will it head for Mars. I don't see this as merely a prototyping effort for the BFR. It is the BFR for next 10+ years -- the World's BFR.Just to clarify, do you mean the original ITS Spaceship being built as the 2nd stage for the mini-ITS first stage? Meaning that only the first stage is downscaled to 9m? How would that work with the factory constraints that limit the first stage to a 9m diameter? Surely both stages need to be downscaled.The spaceship built for the 9m booster will be a sub-scale ITS upper stage from that described last IAC, IMO. As a sub-scale vehicle, it will be difficult to use a redundant set of full vacuum optimized nozzles plus landing engine considerations if the full scale Raptor is the engine. Therefore, I believe the subscale engine would be best for the 9m spaceship (OML might be 12m, just as OML for 12m spaceship was 17m).
Quote from: M.E.T. on 09/13/2017 01:10 pmQuote from: AncientU on 09/13/2017 01:05 pmIMO, the larger Raptor engine will be on the stand this year (next 12 months) and be used to power the booster. If the full spaceship is built for the 9m, which I think likely, it may use the smaller version, as may a conventional upper stage use maybe 3 of these engines. 12Mlbs lift-off thrust is almost a given...I think the planned use and lifetime of this ITSy will be most interesting aspect of IAC 2017 -- when will it be built and when will it head for Mars. I don't see this as merely a prototyping effort for the BFR. It is the BFR for next 10+ years -- the World's BFR.Just to clarify, do you mean the original ITS Spaceship being built as the 2nd stage for the mini-ITS first stage? Meaning that only the first stage is downscaled to 9m? How would that work with the factory constraints that limit the first stage to a 9m diameter? Surely both stages need to be downscaled.The spaceship built for the 9m booster will be a sub-scale ITS upper stage from that described last IAC, IMO. As a sub-scale vehicle, it will be difficult to use a redundant set of full vacuum optimized nozzles plus landing engine considerations if the full scale Raptor is the engine. Therefore, I believe the subscale engine would be best for the 9m spaceship/upper stage (OML might be 12m, just as OML for 12m spaceship was 17m).
Quote from: AncientU on 09/13/2017 01:52 pmQuote from: M.E.T. on 09/13/2017 01:10 pmQuote from: AncientU on 09/13/2017 01:05 pmIMO, the larger Raptor engine will be on the stand this year (next 12 months) and be used to power the booster. If the full spaceship is built for the 9m, which I think likely, it may use the smaller version, as may a conventional upper stage use maybe 3 of these engines. 12Mlbs lift-off thrust is almost a given...I think the planned use and lifetime of this ITSy will be most interesting aspect of IAC 2017 -- when will it be built and when will it head for Mars. I don't see this as merely a prototyping effort for the BFR. It is the BFR for next 10+ years -- the World's BFR.Just to clarify, do you mean the original ITS Spaceship being built as the 2nd stage for the mini-ITS first stage? Meaning that only the first stage is downscaled to 9m? How would that work with the factory constraints that limit the first stage to a 9m diameter? Surely both stages need to be downscaled.The spaceship built for the 9m booster will be a sub-scale ITS upper stage from that described last IAC, IMO. As a sub-scale vehicle, it will be difficult to use a redundant set of full vacuum optimized nozzles plus landing engine considerations if the full scale Raptor is the engine. Therefore, I believe the subscale engine would be best for the 9m spaceship/upper stage (OML might be 12m, just as OML for 12m spaceship was 17m).Engine redundancy is nice to have but it isn't a necessary design requirement.
Just chiming in, I'm thinking (and hoping) that AMOS-6 and the subsequent COPV testing showed them a LOT about what carbon fiber can and cannot do. Hopefully that will help prevent an AMOS-6 2.0, where instead of just the pad being wrecked (F9), Florida's Eastern coast explodes (ITS).