I guess the whole SSTO idea doesn't work because of lift off thrust. Raptor is powerful, but with a full propellant load Starship has a TWR under 1. It would need two more engines to have any shot at it. Starship thrust is appropriately scaled for what it's supposed to do.
Add 2 to 4 more Raptors for Starship point to point on Earth. You can go surprisingly far, even with low lift/drag. This was an unexpected result.
Ah, so single-stage point-to-point? That sounds way better.
Yeah, *way* better. Dramatically improves cost, complexity & ease of operations. Distances of ~10,000 km with decent payload seem achievable at roughly Mach 20.
An engine arrangement something like this could be good for P2P. Max thrust at sea level would be more important than Isp in a vacuum.
And bear in mind that 10,000km is still not enough for all routes. It gets you things like London-USA(48 states) or LA-Tokyo, but LA-Sydney, NY-Mumbai or Auckland-Anywhere-Not-In Oceania are all too far for a single hop.
An engine arrangement something like this could be good for ballistic P2P. Max thrust at sea level would be more important than Isp in a vacuum.
They expect that raptor will get a better thrust to weight and slightly higher isp over time. That should be enough to go to 15000km.
Quote from: Crispy on 05/30/2019 10:33 amAnd bear in mind that 10,000km is still not enough for all routes. It gets you things like London-USA(48 states) or LA-Tokyo, but LA-Sydney, NY-Mumbai or Auckland-Anywhere-Not-In Oceania are all too far for a single hop.LA to Tokyo on SS gets you across the Northern Pacific. From Tokyo you can take SS to Sydney, Auckland, and Mumbai. For the Southern Pacific, Auckland to Santiago and then Santiago to LA.10,000 km is enough with the right routes.
It'll be disappointing if platforms lack a Super Heavy. I liked P2P as a sneaky way of building out mass BEO transit. Better to get a business going and build on it I suppose.I'm sure they'll be a push for SH P2P flights from Gwynne. How else will she get home from Saudi Arabia in time for dinner?
Hi everybody! (First post here)While single stage P2P can be great from the operations point of view, I would be concerned about passengers comfort during launch. With SH, they can use lower T/W during launch to lower the Gs that the passengers experience. They can assume some gravity loses since the whole system has so much total Delta-V that they will get there anyway. But to get far with only the SH will requiere higher accelerations during launch.(I didn't run any numbers, that's just mental inequations)
Quote from: Crispy on 05/30/2019 10:33 amAnd bear in mind that 10,000km is still not enough for all routes. It gets you things like London-USA(48 states) or LA-Tokyo, but LA-Sydney, NY-Mumbai or Auckland-Anywhere-Not-In Oceania are all too far for a single hop.True, but much lower start-up - and on-going - cost to not need SH. So can expand to all routes later, with SH, if demand warrants it. Initially people could potentially do two flights on some route if there's demand. For example, NY-Tokyo via LA or London? It may be that SS on it's own can cover enough of the market that there isn't a business case to add in complexity of using SH too.
Quote from: RonM on 05/30/2019 03:19 pmQuote from: Crispy on 05/30/2019 10:33 amAnd bear in mind that 10,000km is still not enough for all routes. It gets you things like London-USA(48 states) or LA-Tokyo, but LA-Sydney, NY-Mumbai or Auckland-Anywhere-Not-In Oceania are all too far for a single hop.LA to Tokyo on SS gets you across the Northern Pacific. From Tokyo you can take SS to Sydney, Auckland, and Mumbai. For the Southern Pacific, Auckland to Santiago and then Santiago to LA.10,000 km is enough with the right routes.Sydney-Honolulu and Honolulu-New York are both about 8000 km. Landing and launching without disembarking should only add about 30 minutes to the flight, so a direct but not non-stop Sydney-Honolulu-New York flight would be about 1:15 instead of 45 minutes in the air. Much better than the current ~22 hours.
