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mrhuggy
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« Reply #30 on: 07/31/2010 11:32 AM » |
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Instead of transporting big 6-10m stages from Hawthorn to Cape. How about building the the tanks at the Cape, engines and avionics at Hawthorn and doing the final assembly there.
Imagine the jobs that would be created and the happy politicians.
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rklaehn
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« Reply #31 on: 07/31/2010 11:32 AM » |
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The greatest sin of the budget debate will be choosing a no-competition rocket. Crushing the ambition and capabilities of such unique companies (like ULA and SpaceX) will be a real sin. But the demand for "job creation" is stronger than just about anything else.
Or maybe they want something derived from a vehicle that already works and is minimum risk, cost and schedule to develop
You mean the altas V? Ares V is a completely new launch vehicle where the biggest commonality with shuttle is the color scheme.
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ugordan
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« Reply #32 on: 07/31/2010 12:01 PM » |
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I am not sure if they are planning to use the gas generator exhaust for roll control. It looks like they plan to feed it into the engine bell like the f1 did.
Hmmm, looks like you're right, judging also from the engine flow diagram. I found their comparison of a RS-84 vs. a GG engine performance mildly shocking. Does the same performance in the end really sound plausible?
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ugordan
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« Reply #33 on: 07/31/2010 12:04 PM » |
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So why is SpaceX developing HLVs beyond Saturn V when we are told incessantly by the NuSpace crowd they are not necessary ? Also why would the DoD develop a 1.7mlbf RP-1 engine now if SpaceX are already doing this and NASA won't be doing one now ?
A proposed evolution plan and actually developing are two very different things. Which part of the presentations indicated to you they actually are developing any of this?
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marsavian
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« Reply #34 on: 07/31/2010 01:32 PM » |
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The greatest sin of the budget debate will be choosing a no-competition rocket. Crushing the ambition and capabilities of such unique companies (like ULA and SpaceX) will be a real sin. But the demand for "job creation" is stronger than just about anything else.
Or maybe they want something derived from a vehicle that already works and is minimum risk, cost and schedule to develop
You mean the altas V? Ares V is a completely new launch vehicle where the biggest commonality with shuttle is the color scheme.
A SD-HLV will be cheaper and quicker to the 75-130 tons requirement than any Atlas V derivative.
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marsavian
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« Reply #35 on: 07/31/2010 01:43 PM » |
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So why is SpaceX developing HLVs beyond Saturn V when we are told incessantly by the NuSpace crowd they are not necessary ? Also why would the DoD develop a 1.7mlbf RP-1 engine now if SpaceX are already doing this and NASA won't be doing one now ?
A proposed evolution plan and actually developing are two very different things. Which part of the presentations indicated to you they actually are developing any of this?
SpaceX are not going to stop at Falcon 9 (Heavy) if they can help it. They would not be spending development time and money now doing research if that was their intention. On page 3 of the Propulsion presentation there is the title 'Near-term Propulsion Needs'. Clearly the case for BEO exploration/exploitation with only 30mT vehicles has not convinced Elon Musk  .
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mike robel
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« Reply #36 on: 07/31/2010 01:47 PM » |
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So just what makes Saturn V class launch vehicles sustainable in these peoples eyes while everyone else says they are not and that we could never have sustained them in the first place?
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rklaehn
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« Reply #37 on: 07/31/2010 01:50 PM » |
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A SD-HLV will be cheaper and quicker to the 75-130 tons requirement than any Atlas V derivative.
If NASA was actually willing to build a genuinely shuttle-derived vehicle like DIRECT, it might be quicker (though probably not cheaper). But there is little evidence that MSFC will not just continue building Ares I/V if given the chance. I think that MSFC is institutionally incapable of building a working launch vehicle, let alone a cheap one. But this is getting too off-topic for this thread.
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ugordan
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« Reply #38 on: 07/31/2010 01:55 PM » |
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SpaceX are not going to stop at Falcon 9 (Heavy) if they can help it.
The available money and reality will do that for them. A Merlin 2 is projected to take more than the company has spent in total up until now and cost $50M a piece and it would be a replacement for the 9 Merlin 1Ds. That's almost the price of the entire F9 booster right there. Despite these dreams of heavy lift, F9 will be their commercial revenue generator for quite some time to come. So what's the business incentive for making that vehicle more expensive?
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rklaehn
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« Reply #39 on: 07/31/2010 01:57 PM » |
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So just what makes Saturn V class launch vehicles sustainable in these peoples eyes while everyone else says they are not and that we could never have sustained them in the first place?
What is so difficult about this? Once EELV class launch vehicles no longer have sufficient capacity to satisfy demand, you build a bigger one. But not before. Currently all existing EELV infrastructure is underutilized. It would be insane to build a saturn V class launch vehicle before maxing out the existing capacity. And that is exactly what NASA proposed to do with constellation.
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rklaehn
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« Reply #40 on: 07/31/2010 01:59 PM » |
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SpaceX are not going to stop at Falcon 9 (Heavy) if they can help it.
The available money and reality will do that for them. A Merlin 2 is projected to take more than the company has spent in total up until now and cost $50M a piece and it would be a replacement for the 9 Merlin 1Ds. That's almost the price of the entire F9 booster right there.
I wondered about that price tag too. But I'm pretty sure the 50M USD is a typo. It would make no sense whatsoever to build an engine with 9 times the thrust of a merlin 1c if it costs much more than nine times as much...
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marsavian
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« Reply #41 on: 07/31/2010 01:59 PM » |
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So just what makes Saturn V class launch vehicles sustainable in these peoples eyes while everyone else says they are not and that we could never have sustained them in the first place?
Canceling the last Saturn missions when the rockets had already been paid for and built shows that this was more a political decision. Apparently some NuSpace guys sold NASA on the idea of a cheap RLV that would fly frequently and revolutionize Space travel which are quite similar to the stories being peddled these days .
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Nascent Ascent
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« Reply #42 on: 07/31/2010 02:21 PM » |
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So just what makes Saturn V class launch vehicles sustainable in these peoples eyes while everyone else says they are not and that we could never have sustained them in the first place?
Because Musk's long term goal is Mars colonization. Entrepreneurship is a wonderful thing.
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SpacexULA
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« Reply #43 on: 07/31/2010 02:21 PM » |
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I wondered about that price tag too. But I'm pretty sure the 50M USD is a typo. It would make no sense whatsoever to build an engine with 9 times the thrust of a merlin 1c if it costs much more than nine times as much... It does, because even though the Merlin 2 would likely be more than 9 times as expensive, it would not weigh 9 times as much, use less than 9 times the mass in plumbing, or consume less than 9 times as much fuel as a Merlin 1c. Larger engines are more efficient in flight. That was part of the criticism of the Falcon 9 architecture.
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rklaehn
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« Reply #44 on: 07/31/2010 03:13 PM » |
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I wondered about that price tag too. But I'm pretty sure the 50M USD is a typo. It would make no sense whatsoever to build an engine with 9 times the thrust of a merlin 1c if it costs much more than nine times as much...
It does, because even though the Merlin 2 would likely be more than 9 times as expensive, it would not weigh 9 times as much, use less than 9 times the mass in plumbing, or consume less than 9 times as much fuel as a Merlin 1c. Larger engines are more efficient in flight.
That was part of the criticism of the Falcon 9 architecture.
Of course going to a larger engine will get you slightly better Isp and T/W, at the expense of engine-out capability. But that would not justify going to an engine that costs $50M instead of 9 eninges that cost maybe $2M each. That's why I am certain that $50M is just a typo.
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