Quote from: rakaydos on 05/04/2017 08:38 amQuote from: gospacex on 05/04/2017 08:20 amQuote from: rakaydos on 05/03/2017 09:18 pmI've been converted to the "no raptor upper stage on falcon family" belief.It does provide some benifit, before ITS comes online.It's not known when ITS would come online. 2022, say? That's 5 years from now.QuoteBut once ITS comes online it's entirely obsolite, which puts a cap on how much it can earn for SpaceX over what the Mvac stage can. And it's pretty clear that how much it can earn is less than how much it would cost to develop and build that stageA large fraction of the cost is in developing the engine, and know what? SpaceX is _already_ developing this engine. They already spending these money, they can not be "saved".Also, with Raptor upper stage, they can drop MVac (which is "three times more expensive than sea-level Merlins").Yes, yes, "It wont cost THAT much to make" and "It does things Falcon heavy cant now." I get that.The problem is that the "things it does that falcon cant" isnt big enough to cover even "Doesnt cost that much," especially since infrastructure changes (fuel lines on the erector, ect) actually would -reduce- the number of paying flights compared to a kerlox-only falcon family.ITS cant use the falcon pads anyway, so there's no reason to shut down the falcon pads to add methlox.Yip. I'm pretty much converted to this viewpoint. But it would be sad if this situation (Falcon architecture only) lasts much longer than planned, if ITS say only comes online in 2035 instead of 2025 or something along those lines. Then SpaceX is going to start falling behind their competitors, and that doesn't seem like the type of company they aspire to be.Hence my view that ITS has to be developed as soon as possible, then.
Quote from: gospacex on 05/04/2017 08:20 amQuote from: rakaydos on 05/03/2017 09:18 pmI've been converted to the "no raptor upper stage on falcon family" belief.It does provide some benifit, before ITS comes online.It's not known when ITS would come online. 2022, say? That's 5 years from now.QuoteBut once ITS comes online it's entirely obsolite, which puts a cap on how much it can earn for SpaceX over what the Mvac stage can. And it's pretty clear that how much it can earn is less than how much it would cost to develop and build that stageA large fraction of the cost is in developing the engine, and know what? SpaceX is _already_ developing this engine. They already spending these money, they can not be "saved".Also, with Raptor upper stage, they can drop MVac (which is "three times more expensive than sea-level Merlins").Yes, yes, "It wont cost THAT much to make" and "It does things Falcon heavy cant now." I get that.The problem is that the "things it does that falcon cant" isnt big enough to cover even "Doesnt cost that much," especially since infrastructure changes (fuel lines on the erector, ect) actually would -reduce- the number of paying flights compared to a kerlox-only falcon family.ITS cant use the falcon pads anyway, so there's no reason to shut down the falcon pads to add methlox.
Quote from: rakaydos on 05/03/2017 09:18 pmI've been converted to the "no raptor upper stage on falcon family" belief.It does provide some benifit, before ITS comes online.It's not known when ITS would come online. 2022, say? That's 5 years from now.QuoteBut once ITS comes online it's entirely obsolite, which puts a cap on how much it can earn for SpaceX over what the Mvac stage can. And it's pretty clear that how much it can earn is less than how much it would cost to develop and build that stageA large fraction of the cost is in developing the engine, and know what? SpaceX is _already_ developing this engine. They already spending these money, they can not be "saved".Also, with Raptor upper stage, they can drop MVac (which is "three times more expensive than sea-level Merlins").
I've been converted to the "no raptor upper stage on falcon family" belief.It does provide some benifit, before ITS comes online.
But once ITS comes online it's entirely obsolite, which puts a cap on how much it can earn for SpaceX over what the Mvac stage can. And it's pretty clear that how much it can earn is less than how much it would cost to develop and build that stage
Profit is only one of SpaceX's internal goals, and only a means at that - not an end of itself.
have ZERO problems raising capital for either SpaceX or Tesla.
If you assume ITS will take 5 years to become operational, then you should assume a Raptor Upper Stage would take at least half a much to become operational
A Raptor Upper Stage for Falcon 9/Heavy would make a lot of sense if ITS (or mini ITS) will actually take a long time to fly.But lets think rationally. Without a fully certified Raptor, there's neither ITS nor any raptor upper stage. Reportedly the next big technical challenge is the big composite fuel tank, which is already being tested. Perhaps building the full sized ITS could require several billion to make (including the cost to prepare a new factory), but so far Elon Musk has been on a huge roll and have ZERO problems raising capital for either SpaceX or Tesla. The assumption of 3.66m diameter stages makes every sense for rockets that aren't reusable, but for a fully reusable system (that requires zero refurb on a launch by launch basis and only need refurb every 20-100 launches), the road transportable model is mostly obsolete.
Yes, a Raptor Upper Stage would deliver significant performance improvements to F9/FH, but F9 Block V + FH Block V will be performance beasts with full booster reuse.
If you assume ITS will take 5 years to become operational, then you should assume a Raptor Upper Stage would take at least half a much to become operational, which possibly doesn't even recoup the waste in design talent taken away from ITS to build this new upper stage. Building more upper stages cost money, but I think the truly scarce resource is the engineering talent.
In reply to a post on: SpaceX Falcon Heavy Discussion (Thread 5)Quote from: envy887 on 05/03/2017 11:19 pm Profit is only one of SpaceX's internal goals, and only a means at that - not an end of itself.A common characteristic of people that keep defending this raptor upper stage is the unwillingness to accept that SpaceX must at least break even. In fact, it must produce LOTS of CASH on a variable per launch calculation basis, so that per launch positive cash flow can pay for the massive SpaceX payroll and other fixed and R&D costs.If you take a few days to understand the business side of things, you'll see that this whole raptor upper stage endeavour could make a lot of sense technically, but makes ZERO sense when you consider $$$.Elon Musk has said several times, that he doesn't care too much about profit, but that if his companies don't at least nearly break even, he can't justify them to investors and the whole effort become a house of cards.Remember Musk has two degrees, Physics and Economics. He seems to use both skills very wisely.
ITS cant use the falcon pads anyway, so there's no reason to shut down the falcon pads to add methlox.
...The goal of ITS isn't just capacity, it's capability. Capabilities that Falcon will never have: full and rapid reuse; on-orbit refueling; lifting entry with retropropulsive landing; ISRU for propellants on Mars; Mars ascent and return....
No, it's not "mostly obsolete". It's completely and totally dead. A 6m booster needs new transport and test facilities, and a 12m booster needs new transport, test, manufacturing, integration, and launch facilities. As soon as a new booster is required you add at least 3 years , and a 12m booster at least 5 years, to any plans for an upper stage that uses existing (slightly modified) infrastructure.The goal of ITS isn't just capacity, it's capability. Capabilities that Falcon will never have: full and rapid reuse; on-orbit refueling; lifting entry with retropropulsive landing; ISRU for propellants on Mars; Mars ascent and return.Jim assumes ITS will take at least 10 years to be operational, and I don't think he's far off (it needs new transport, test, manufacturing, integration, and launch facilities). A Raptor upper stage could yield the same capability (at lower but still sufficient capacity) in 2-3 years.Profit isn't remotely an argument that favors a full ITS system (or even an intermediate methalox booster) over using Raptor on Falcon. There are enormous upfront costs for required extra infrastructure, and no clear path to any breakeven payback. Raptor on Falcon has incremental infrastructure costs (or nearly none at all if they build Boca Chica to support it from day 1).
If you read carefully, I said ITS OR MINI ITS. Not AND.A full scale ITS might indeed require a new pad, but a mini ITS could be sized up to the limit of LC39A (1/3 of ITS lift off thrust matches Saturn V very well).
The performance capability of FH is too small even with a substantial Raptor upper stage to throw a large mass towards Mars.The expected refurb costs of FH boosters would be a significant bottleneck to send a large volume of people and cargo towards Mars.
I don't see a reason for anxiety even if it takes 10 years for ITS to be flying. Even IF there's no mini ITS in between.If it takes 5 or 8 years to a mini ITS, so be it. I think SpaceX can do it within 3-5 years after Raptor is flight qualified.A larger single core methane booster is a huge part of the ITS solution.I think people should have some humility and accept that SpaceX knows a heck of a lot more than you or me, they say the path forward is ITS, with people conjuring this Raptor upper stage to F9/FH based on a contract with USAF that clearly is for the engine only, mentioning an upper stage strictly as one possible application for the engine (as well as the unlikely usage of Raptor for non SpaceX rockets). The USAF contract doesn't mention ITS cause mentioning ITS on a development contract isn't strategical for either USAF nor SpaceX.Maybe the path forward is a mini ITS to reduce infrastructure costs. A mini ITS would be even better as a complete replacement to FH and likely F9 too.Mini ITS would both reduce SpaceX margins to access to orbital payloads, bring substantial capabilities towards other non Mars revenue too.My hunch is this Raptor development contract was one of the agreements that came out of the Falcon 9 USAF certification settlement. One of the several ways in which USAF agreed to make up for SpaceX. I wouldn't read that much further than a means to incentive SpaceX to bring new LVs to market which then USAF/DoD can use.
Nice work. Some questions on the schedule that can't necessarily be answered without knowing internal development schedule:-Is the RVac US for FH able to land cargo on Mars? Namely in the 2020 window vs the ITS planned 2022 window.
-Mars infrastructure: how much can be tested via Red Dragon Flights or would these items need to be larger?
-If ITS flights to Mars slip to the right what does this mean to the development of ground infrastructure?
-Would the RVac FH US allow for development of Mars infrastructure concurrent to ITS development, so that a slip in ITS first flight to Mars doesn't cause a slip in ground hardware testing on Mars?
Quote from: macpacheco on 05/04/2017 11:07 amhave ZERO problems raising capital for either SpaceX or Tesla.Capital for things investors hope to profit from. Like the Internet constellation.If you have evidence of SpaceX receiving funding from philanthropic billionaires, I'd really like to hear about it.
It does provide some benifit, before ITS comes online. But once ITS comes online it's entirely obsolite, which puts a cap on how much it can earn for SpaceX over what the Mvac stage can. And it's pretty clear that how much it can earn is less than how much it would cost to develop and build that stage, rebuild a launch site for mixed propellants (displacing normal paying flights, which counts as a cost), and other expences of such a program.
The problem is that the "things it does that falcon cant" isnt big enough to cover even "Doesnt cost that much," especially since infrastructure changes (fuel lines on the erector, ect) actually would -reduce- the number of paying flights compared to a kerlox-only falcon family.
Quote from: Eerie on 05/04/2017 11:28 amQuote from: macpacheco on 05/04/2017 11:07 amhave ZERO problems raising capital for either SpaceX or Tesla.Capital for things investors hope to profit from. Like the Internet constellation.If you have evidence of SpaceX receiving funding from philanthropic billionaires, I'd really like to hear about it.WSJ has estimated "CommX's" net revenue potential at up to ~$22B a year, >$2B more than NASA's current budget. If that project works out half as well as WSJ thinks funding will be the least of their problems.