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RE: Why no Mars
October 6, 2024 at 7:22 pm
(October 6, 2024 at 4:43 pm)AFTT47 Wrote: .A practical orbital system where the booster is routinely and reliably reused at economic benefit is something most engineers thought impossible. When starship is operational, it will reduce the cost of lifting heavy loads to orbit ten-fold.
It should be noted that the SRBs for the Space Shuttle were reusable and reused.
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RE: Why no Mars
October 6, 2024 at 11:07 pm
(October 6, 2024 at 7:22 pm)Thumpalumpacus Wrote: (October 6, 2024 at 4:43 pm)AFTT47 Wrote: .A practical orbital system where the booster is routinely and reliably reused at economic benefit is something most engineers thought impossible. When starship is operational, it will reduce the cost of lifting heavy loads to orbit ten-fold.
It should be noted that the SRBs for the Space Shuttle were reusable and reused.
Yes indeed. The 3 liquid-fuel main engines were also refurbished. Of course the orbiters themselves were reused. Here were the problems:
No money was saved by recovering the spent SRB casings. Indeed, it probably cost more to recover them and prepare them for receiving fresh fuel segments than to just build new ones.
The 3 main engines required extensive refurbishment and took a lot of time to be accomplished.
The orbiters themselves were labor intensive because of those damn heat shield tiles. They never did get that problem really licked.
In the end, the shuttle ended up being enormously expensive. It cost about $1.5 billion per launch compared with about $68 million for Falcon9. That's 22 times the cost! Part of the problem was the way the government works. Multiple agencies with multiple (and often contradictory) requirements had a hand in the design process. Different components were built by different suppliers in different states (all looking to get the votes of different senators in the approval process). The reusability of the shuttle was little more than optics. It did nothing to reduce the cost of space operations. In fact, it was probably the shuttle program that poisoned the aerospace industry against the idea of truly practical reusability in the first place. It came to be seen as a fantasy and a scam.
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RE: Why no Mars
October 6, 2024 at 11:33 pm
(October 6, 2024 at 11:07 pm)AFTT47 Wrote: The orbiters themselves were labor intensive because of those damn heat shield tiles. They never did get that problem really licked.
Musk also didn't solve this problem on Starship as it burns in the atmosphere upon return, and there is no reason to believe that he will solve this since he doesn't possess some knowledge others don't have.
teachings of the Bible are so muddled and self-contradictory that it was possible for Christians to happily burn heretics alive for five long centuries. It was even possible for the most venerated patriarchs of the Church, like St. Augustine and St. Thomas Aquinas, to conclude that heretics should be tortured (Augustine) or killed outright (Aquinas). Martin Luther and John Calvin advocated the wholesale murder of heretics, apostates, Jews, and witches. - Sam Harris, "Letter To A Christian Nation"
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RE: Why no Mars
October 7, 2024 at 1:19 am
(October 6, 2024 at 11:33 pm)Fake Messiah Wrote: (October 6, 2024 at 11:07 pm)AFTT47 Wrote: The orbiters themselves were labor intensive because of those damn heat shield tiles. They never did get that problem really licked.
Musk also didn't solve this problem on Starship as it burns in the atmosphere upon return, and there is no reason to believe that he will solve this since he doesn't possess some knowledge others don't have.
As I pointed out before, Starship is in development. You understand how the SpaceX development cycle works, right? I assume you do since you are such an enthusiastic critic. Just in case you don't:
SpaceX advances the design to a point and then launches with that design and sees what happens. Tweak the design based on the results and try again. Rinse and repeat. Eventually, you arrive at your goal. Definitely not the way NASA does it but it sure worked for Falcon9. Starship is much more ambitious so a longer cycle is to be expected. Based on SpaceX's track record though, I'm confident they will succeed.
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RE: Why no Mars
October 7, 2024 at 8:49 am
(This post was last modified: October 7, 2024 at 8:50 am by Thumpalumpacus.)
TBO is a fact of life on any engine. Has Musk reduced that drastically?
(October 7, 2024 at 1:19 am)AFTT47 Wrote: SpaceX advances the design to a point and then launches with that design and sees what happens. Tweak the design based on the results and try again. Rinse and repeat. Eventually, you arrive at your goal.
Gosh, it's like no other company in the world does that.
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RE: Why no Mars
October 7, 2024 at 10:46 am
(This post was last modified: October 7, 2024 at 10:47 am by Fake Messiah.)
(October 7, 2024 at 1:19 am)AFTT47 Wrote: As I pointed out before, Starship is in development. You understand how the SpaceX development cycle works, right? I assume you do since you are such an enthusiastic critic. Just in case you don't:
Or maybe it's just one of Musk's many grifts (after all, according to Musk, this thing was supposed to be on Mars years ago but it's still battling to be in orbit) like his Tesla truck whose hauling abilities beat rail in pricing. Or like that farcical Tesla robot or hyperloop - or maybe you think that the Tesla robot and hyperloop are also in development?
teachings of the Bible are so muddled and self-contradictory that it was possible for Christians to happily burn heretics alive for five long centuries. It was even possible for the most venerated patriarchs of the Church, like St. Augustine and St. Thomas Aquinas, to conclude that heretics should be tortured (Augustine) or killed outright (Aquinas). Martin Luther and John Calvin advocated the wholesale murder of heretics, apostates, Jews, and witches. - Sam Harris, "Letter To A Christian Nation"
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RE: Why no Mars
October 7, 2024 at 12:26 pm
(September 30, 2024 at 4:37 pm)BrianSoddingBoru4 Wrote: (September 30, 2024 at 4:23 pm)bemore Wrote: Having humanity on another planet is a nice back up, should Earth get hit by something from space.
Earth gets hit by stuff all day, every day. But I assume you’re thinking about a massive asteroid strike, big enough to wipe everything out.
First of all, by the time we’d be able to establish a viable colony on Mars, humankind would likely be extinct already.
Secondly, what’s to prevent Mars from suffering the same sort of impact?
Lastly, how would you convince people to go? Remember - the vast majority of human beings live out their entire lives less than 200km from where they were born.
Boru
In fact because Mars is much smaller and has a much less dense atmosphere, the impact that would be a species destroyer there will be much smaller than the equivalent for Earth.
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RE: Why no Mars
October 7, 2024 at 2:02 pm
(October 7, 2024 at 8:49 am)Thumpalumpacus Wrote: TBO is a fact of life on any engine. Has Musk reduced that drastically?
(October 7, 2024 at 1:19 am)AFTT47 Wrote: SpaceX advances the design to a point and then launches with that design and sees what happens. Tweak the design based on the results and try again. Rinse and repeat. Eventually, you arrive at your goal.
Gosh, it's like no other company in the world does that.
The space shuttle main engines burned liquid hydrogen. They are highly complex and are the worst choice for a motor you want to reuse. Falcon 9 uses kerosine motors which are more suitable for that. Is the improvement that dramatic? Well, how about 20+ reuses with minimal maintenance? How about 1/25th the launch cost? I would call that a "yes".
I don't know what the point was of the comment about other companies using the same modus operandi as SpaceX. Honestly, I don't know of any. Certainly there are no other aerospace companies that operate that way. I only brought it up to help point out what should be obvious to anyone paying the least bit of attention: Starship is in development. The four flights to date have been test flights, not operational flights.
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RE: Why no Mars
October 7, 2024 at 2:10 pm
(October 1, 2024 at 12:19 am)Thumpalumpacus Wrote: (October 1, 2024 at 12:03 am)Silver Wrote: Soon.
In human terms? Like a week from Wednesday?
I think we'll be around for quite a bit longer. Maybe long enough to catch a stray comet, but that depends. And I think we'll outlive the first few attempts to colonize Mars as well.
What would be cool is sending Musk on the first mission, and then just shutting off the radio.
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RE: Why no Mars
October 7, 2024 at 2:30 pm
(This post was last modified: October 7, 2024 at 2:32 pm by Thumpalumpacus.)
(October 7, 2024 at 2:02 pm)AFTT47 Wrote: Certainly there are no other aerospace companies that operate that way.
Of course they do. That's what test regimes are all about, and there's not an airplane manufactured in America that isn't handled this way. Build it, fly it, identify issues, tweak the design, test to see if the fix works ... lather, rinse, repeat. The process often works will; it isn't unique to SpaceX; and sometimes we learn that what we're trying to build is simply beyond the available tech. If it's still in development don't you think it's premature to assume its success?
I'd imagine other industries practice this heuristic as well. Pharmaceuticals, for instance. I doubt they just release drugs into the wild without extensive testing. Auto manufacturers probably do this as well.
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