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Falcon Super Heavy/Starship - General Development Discussion

Discussion in 'SpaceX' started by Grendal, Nov 4, 2017.

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  1. mongo

    mongo Well-Known Member

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    How do you refuel an Earth to Mars ship for the return voyage? Or does it carry the full round trip fuel load with it? Are you allowing for any aero braking on either end?
     
  2. Ulmo

    Ulmo Active Member

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    I transcribed some of Elon Musk's executive summary in his latest "Starship{sic} Update":

    Brackets are mine. Single brackets are me channeling his meaning, and double brackets are me interpreting his meaning into reality (since he touched upon a few fake news topics; notice how he made them irrelevant, so you can bitch and moan with all your useful idiotness from “both sides” but it doesn’t matter here).

    Transcribed from SpaceX speech by Elon Mush yesterday (2019-09-28):

    His closing of his introductory speech of “Starship{sic} Update”:

    As far as we know, we are the only consciousness or the only life that’s out there. There might be other life, but we’ve seen no signs of it. People often ask me “What do you know about the aliens?”, and I’m like, “Man, I tell you, but I’m pretty sure I’d know, you know, if there were aliens; I’ve not seen any sign of aliens.” “Why is the military hiding aliens in Area 51?”, That’s popular meme. Let me tell you: the fastest way to increase defense funding would be to bring out {and show and say} “Hey, we found an alien!” Feel like “Ahhh! We need more money for defense! Definitely!” Guaranteed, that would be like on display in two seconds.

    So, the reality is as far as we know, this is the only place at least in this part of the galaxy or the milky way where there is consciousness. And it’s taken us a long time to get to this point. According to the geological records, Earth’s been around for about 4.5 billion years. Although it was mostly molten magma for about half a million years. But still, at least several billion years with at least bacterial life, and multicellular lifeforms for several hundred million years.

    But the other interesting part is the Sun is gradually getting hotter and bigger and over time even in the absence of {{man-made “}}global warming{{“}} ({{“}}man-made stuff{{"}}) the sun will expand and it will overheat the Earth. My guess is it is probably — On human time scales this is a long time — there’s only several hundred million years left. That’s all! That’s all we’ve got! {{Can someone please double check that?}} Ok? Several hundred million years. But thought of from an evolutionary standpoint, basically, if it took an extra 10% longer for conscious life to evolve on Earth, it wouldn’t evolve at all, because it would have been incinerated by the Sun.

    So what I’m saying it appears that consciousness is a very rare and precious thing, and we should take whatever steps we can to preserve the light of consciousness, and the window has been opened, only now, after 4.5 billion years has that window opened. That’s a long time to wait, and it might not stay open for long. I’m pretty optimistic by nature {{I share that with him}}, but there’s some chance that window will not be open for long, and I think we should become a multiplanetary civilization while that window is open. And if we do, I think the probable outcome for Earth is even better, because then Mars can help Earth one day {{think of ping pong, helping each other}}. I think we should really do our very best to become a multiplanet species and extend consciousness beyond Earth, and we should do it now.

    Thank you!
     
  3. Cosmacelf

    Cosmacelf Well-Known Member

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    All the searches I found state that the earth will be inhospitable to life in about 1 billion years. So maybe double Elon’s time scale?

    Not that it matters. His argument has more to do with why there isn’t more life around the galaxy rather than what happens to humans. Chances are pretty big that some other catastrophe will kill off humans within the next few hundreds of millions of years.
     
  4. ecarfan

    ecarfan Well-Known Member

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    Watching the presentation last night, I also thought his timeframe was somewhat off. But as you note, not enough to make a difference to the argument he was making.
    Definitely true if humans remain restricted to Earth. Less likely if humans become a multi-planetary species.

    Of course the goal is to explore and inhabit other star systems. Not possible with today’s technology, but in a few centuries, maybe. But if we remain restricted to Earth I believe it is far less likely we will ever figure out how to reach the stars.
     
  5. dhanson865

    dhanson865 Active Member

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    You don't have humans on the first flight to mars but you have to send consumables for them (water, air, food) so they have supplies/emergency reserves when they get there. Since the refueling will take CO2 from the atmosphere maybe the cargo/supply water from the ship can a partial feed stock for the automated propellant factory (still lighter or easier to store than the equivalent mass of CH4 during flight?)?

    Assuming the automated propellant process works it can radio home before the next flight comes in giving a tally of CH4, O2, and H2O supplies (both outputs and input).

    presumably the scout droids scour the places you expect to harvest H20 on mars and mark them for the crews to come.

    Then maybe the humans can do the harder work of getting more H2O from mars sources once they know they have emergency reserves brought from home and the preliminary work has been done ahead of time.

    I seriously doubt they'll be able to fully automate H20 harvesting before the humans get there.
     
  6. Singer3000

    Singer3000 Member

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    Yes for the first crew things will be pretty tough indeed. I dare say that by the time the first crewed mission departs, there will have been at least 3 cargo ship launch windows in prior years (2022,2025,2027), with who knows how many vehicles launched per window.

    What if they sent ahead a Starship filled with compressed hydrogen? Given a hydrogen mass percent in methane of 25% that means they'd have enough H2 on hand to make 400MT of methane even if there was no easy to access water, which means about 1,600MT of total propellant (methane is 25% of the fuel mix isn't it?), more than the Starship's fuel capacity. Just mix that with simple electrolysis to get the O2 from the Martian air and you're on your way home again.

    I had a slightly silly thought when I saw the finished height of the gigantic Starship this weekend, followed by the CGI video. The entry hatch to the vessel is about half way up its 55m height. But when it lands on Mars, there isn't going to be a nice convenient bridge to an elevator waiting for the crew. So instead are we going to see the first footprints on Mars after history's most famous abseil? Or a slow and tedious climb down a long rope ladder?
     
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  7. mongo

    mongo Well-Known Member

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    #467 mongo, Sep 30, 2019
    Last edited: Sep 30, 2019
    Right, that is SpaceX's plan. I was asking FoverM how the transit ship makes it back to Earth if there is not a heavy lift ship at Mars, and only purpose build, low cargo capacity, landers are used. (The system they seem to prefer)

    Edit: This side discussion was OT, sorry for the confusion.
     
  8. mongo

    mongo Well-Known Member

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    New site for Starship/ SH:

    Starship

    Lists payload as 100+ tons.
     
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  9. Nikxice

    Nikxice Active Member

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    There's an interesting discrepancy on the height of Starship. SpaceX's new site lists it at 50m/160ft. Maybe just a typo, 50m is actually just over 164ft. The Super Heavy booster is 68m/224ft, which when adding 164ft gets both stages up to the acknowledged 387ft.

    Just made that last pic on their site my desktop background. Rocket to the stars!
     
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  10. bxr140

    bxr140 Active Member

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    The major one that comes to mind is the Saturn 1B, but I'm pretty sure they put the thing way up on a stand because it was the easiest way to use the existing Saturn 5 equipment.

    [​IMG]

    Minotaur C (formerly Taurus) uses a riser stand, but that's evolved out of a quick-launch ICBM meant to be erected on pretty much any pad that could support the static load of the rocket. It is an exhaust thing, but of course the vehicle is super small relative to anything spaceX builds.

    [​IMG]

    Barely related, some silo launches actually lift the vehicle up and out of the silo to make exhaust more manageable. Some do it mechanically, basically on a big lift. The more bad ass ones use essentially a black powder charge to push the missile up and out of the silo and then they turn on the rocket motors.




    This launch pad is literally an oil platform with two submarines welded to the bottom. Waterline at launch is much higher, and obviously they don't launch from Long Beach (where this shot was taken).

    [​IMG]


    Just as a thought experiment, the solution would involve multiple, more specialized vehicles. Sort of like the Apollo missions that had a cmd module, a lander (in that case, essentially a two stage solution), and a re-entry vehicle. One could imagine a mega--tug that provides more space for the occupants during the journey, for instance, then smaller vehicles for the atmospheric duties, especially when carrying personnel.

    Of course SpaceX has surely storyboarded such a mission configuration and have determined that their as-advertised solution is a better option.
     
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  11. ecarfan

    ecarfan Well-Known Member

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    Thanks for your post and all the info! I went to the Wikipedia page Saturn IB - Wikipedia and there is a photo of that launch stand configuration. The page states “Mobile Launcher Platform No. 1 was modified, adding an elevated platform known as the "milkstool" to accommodate the height differential between the Saturn IB and the much larger Saturn V.[7] This enabled alignment of the Launch Umbilical Tower's access arms to accommodate crew access, fueling, and ground electrical connections for the Apollo spacecraft and S-IVB upper stage”. So that was done because for Saturn 1B launches they wanted to use the same launch stand as they would use later for the Saturn V?

    In the case of what SpaceX is now showing as the SH/Starship launch pad/tower, that structure is being purpose built for that vehicle, in the same way that the Ocean Odyssey launch platform was developed by Sea Launch for the Zenit-3SL vehicle, as shown in the last photo you posted (right?).

    So my question about the proposed SH/Starship launch pad/tower is wondering if the high elevation of the rocket is to reduce the cost of building a massive flame trench like the one at LC-39A?
     
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  12. bxr140

    bxr140 Active Member

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    Yeah, that would be my guess. There's probably not many other upsides. Maybe elimination of water suppression?

    I also would bet that, not unlike the Minotaur jalopy, it will be easier to set up multiple launch sites using that configuration rather than digging trenches and building out more complicated infrastructure.
     
  13. HVM

    HVM Savolainen

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    Dark Energy @Alejandro_DebH
    "How are you going to have 39A ready in time for that??? o_O"

    Elon Musk

    "Starship launch structure is being built off-site in steel subsections"

    I also recall that there was an earlier tweet; how the flame deflector is (will be) made from metal and is water-cooled, also how it is faster to build than traditional concrete flame tranches. I just don't find it now.
     
  14. ecarfan

    ecarfan Well-Known Member

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    Okay, so if the rocket engines are that high off the ground the shock wave issues are less severe and water suppression may not be needed?
    Cool, makes sense. I would assume those subsections are being assembled locally and indoors so we don’t know where they are. Could be a contractor, not at the local site where Starship Mk2 is being built.
    Very interesting, thanks!

    Just imagine how it is going to look when FH/Starship launches and right after ignition we may be able to see the full length of the up to 37 Raptor engine exhausts; it will be epic!
     
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  15. bxr140

    bxr140 Active Member

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    Exactly. To be clear, its total speculation on my part...mostly just trying to think of a potential upside to a launch stand beyond not needing to construct a flame trench.

    Water suppression...uhh...suppresses acoustic energy; acoustic energy also dissipates with distance. At some point one could imagine even a near-unheard of amount of energy (like that coming out the business end of SH) being relatively controlled with more passive concepts like diverters and distance. Sidebar, if you double take the sea launch image from above you'll see the diverter under the rocket hole in the main deck. I'm pretty-sure-but-not-positive they don't have a deluge system.

    Random tangent thought, one could imagine a ignition/throttle profile that's engineered to optimize the first few meters of flight for minimized exhaust and thus the need to control exhaust and/or the resulting damage. While that does happen to a small degree with some launchers, historically its been all about maximizing mass performance of the launcher and damage to the launch facility (and subsequent recurring refurbishment) be damned. If anyone is going to take the bigger picture approach of optimizing all elements of a mission even at the expense of performance, it's SpaceX.
     
  16. dkemme

    dkemme Supporting Member

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    No mention of Boca Chica on their site, I'm wondering if this will become a ghost town...

    Would be kinda cool if the first base on Mars was called Boca Chica.
     
  17. mongo

    mongo Well-Known Member

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    Cameron County is Boca Chica, or did you mean calling it by the village name since SpaceX is trying to buy out the whole area?
     

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  18. diplomat33

    diplomat33 Well-Known Member

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    Here is a great one-on-one interview with Elon Musk by the Everyday Astronaut.

     
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  19. Lasairfion

    Lasairfion Member

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    Yeah, I just watched that. It's probably one of the most comfortable Elon interviews that I've seen. Elon and Tim need to get together more often and just geek out over space stuff.
     
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  20. diplomat33

    diplomat33 Well-Known Member

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    I especially like Elon's design philosophy. Question the constraints and simplify. It makes a lot of sense. I do think that Elon is an engineer at heart so he is more comfortable when he can "geek out" about engineering stuff. He is in his element.
     
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