23 Apr 2024, 02:43 [ UTC - 5; DST ]
|
Username Protected |
Message |
Username Protected
|
Post subject: Starship & Moon Landing Complexity … Posted: 14 Aug 2021, 15:38 |
|
|
|
|
|
Joined: 12/22/07 Posts: 12893 Post Likes: +13315 Company: Midwest Chemtrails, LLC Location: KPTK (SE Michigan)
Aircraft: C205
|
|
I have not been closely following the SpaceX/Starship plan for their 2024(?) moon landing. According to the GAO review of SpaceX’s winning submission, it will require sixteen Starship/Super-Heavy launches for each moon landing. I had no idea. Shame on me for not paying attention. Musk has said, maybe as few as four, but that would require giving up heat shields, articulating wings, landing and re-use. And watch that first step out of the lander, it is a doozy (126 feet to the lunar surface). This graphic is from Bezos/Blue’s protest regarding the complexity of the SpaceX proposal. Attachment: 7DABF1CF-FD58-4807-95EC-EB37FF0AA200.jpeg
Please login or Register for a free account via the link in the red bar above to download files.
_________________ Life is a DiY project.
Last edited on 14 Aug 2021, 22:12, edited 1 time in total.
|
|
Top |
|
Username Protected
|
Post subject: Re: Starship & Moon Landing Complexity … Posted: 14 Aug 2021, 16:43 |
|
|
|
|
Joined: 03/15/16 Posts: 695 Post Likes: +365 Location: Charlotte NC
Aircraft: Piper Mirage
|
|
That’s insane!!! It’s crazy that 60 years ago, they did it with way less!!!!
|
|
Top |
|
Username Protected
|
Post subject: Re: Starship & Moon Landing Complexity … Posted: 14 Aug 2021, 19:46 |
|
|
|
|
Joined: 03/05/14 Posts: 2850 Post Likes: +2870 Company: WA Aircraft Location: Fort Worth, TX (T67)
Aircraft: 1969 Bonanza E33C
|
|
Username Protected wrote: SpaceX seems more likely to launch 16 rockets into space than Blue Origin launching 1.
SpaceX is clearly the leader in high rate rocket launches, so doing something 16 times doesn't seem "complex", just repetitive.
Mike C. Perspective
|
|
Top |
|
Username Protected
|
Post subject: Re: Starship & Moon Landing Complexity … Posted: 15 Aug 2021, 09:03 |
|
|
|
|
|
Joined: 04/26/13 Posts: 19944 Post Likes: +19685 Location: Columbus , IN (KBAK)
Aircraft: 1968 Baron D55
|
|
Username Protected wrote: That’s insane!!! It’s crazy that 60 years ago, they did it with way less!!!! But they didn’t do it. Saturn V was fully disposable and it carried less mass to orbit. Lunar Starship is intended to be the launch vehicle, and lander, and also be reusable. It is not intended to land on Earth, so the ‘flaps’ and heat shield are not needed. It’s intended by design requirements to work with Orion, which will return any passengers to Earth. You can think of it as a heavy transport and lunar lander. One hundred metric tonnes of payload to the surface of the moon. It’s so big that it can serve as a lunar base on its own. Yes the multiple refuelings are a bit awkward, but as nobody has yet built a fueling station in LEO, you have to do what you have to do. Bezos is just having a little billionaire fit. In fact, this contract is for a single lunar landing. There is a second contract for repeated flights and landings. The thinking right now is that politics will not accept a one vendor solution, and so the second contract will be given to The National Team despite them having very little evidence of capability. We’ll see. Meanwhile, Elon will continue to do what he does, which is work toward a Mars landing. All of this on-orbit tanking is preparation for that. Always remember that Elon does nothing that doesn’t further his single goal of living on Mars.
_________________ My last name rhymes with 'geese'.
|
|
Top |
|
Username Protected
|
Post subject: Re: Starship & Moon Landing Complexity … Posted: 15 Aug 2021, 12:04 |
|
|
|
|
Joined: 01/06/08 Posts: 4701 Post Likes: +2703
Aircraft: B55 P2
|
|
The Apollo was a single purpose rocket designed by the best rocket engineers in the world, when NASA attracted the best and brightest . (and the occasional Nazi). Rocket engineering is very unforgiving, far more so than aircraft design. When you stop being maximally efficient you lose quickly. Space X is carrying a lot more mass to the moon than they need, possibly including a heat shield(!) It doesn't have a separate assent stage, needs to carry all that mass back to lunar orbit. They use Methane / Oxygen, not the Hydrogen / Oxygen of the upper stages of the Saturn V. The difference in specific impulse goes into an exponential - ends up making a huge difference. The big question is the total cost for multiple flights. Re-usability cuts the cost a LOT, OTOH, 16 launches even of fully reusable vehicles is not cheap. The other big question is schedule and risk - BFR, sorry Spaceship hasn't flown yet. SpaceX had not demonstrated the reentry shielding (which is tricky in that design) or in-flight refueling. I'm worried that NASA picked SpaceX expecting them to fail, as a way to back out of Artemis and make it someone else's fault. Still, it might work Username Protected wrote: That’s insane!!! It’s crazy that 60 years ago, they did it with way less!!!!
|
|
Top |
|
Username Protected
|
Post subject: Re: Starship & Moon Landing Complexity … Posted: 15 Aug 2021, 12:54 |
|
|
|
|
|
Joined: 04/26/13 Posts: 19944 Post Likes: +19685 Location: Columbus , IN (KBAK)
Aircraft: 1968 Baron D55
|
|
Username Protected wrote: Space X is carrying a lot more mass to the moon than they need, possibly including a heat shield(!)
It doesn't have a separate assent stage, needs to carry all that mass back to lunar orbit.
The big question is the total cost for multiple flights. Re-usability cuts the cost a LOT, OTOH, 16 launches even of fully reusable vehicles is not cheap.
The other big question is schedule and risk - BFR, sorry [Starship] hasn't flown yet. SpaceX had not demonstrated the reentry shielding (which is tricky in that design) or in-flight refueling.
I'm worried that NASA picked SpaceX expecting them to fail, as a way to back out of Artemis and make it someone else's fault. Still, it might work Lunar Starship will not have a heat shield. It will not land on Earth, ever. Ascent from the moon will be minus a large amount of heavy cargo and fuel, so while there is no discardable "descent stage", the vehicle itself can be lighter by a large margin. If not, then it will need more fuel, but you get to use it again. There comes a point in Man's habitation of the moon where it is no longer viable to leave half of your spacecraft behind every time you land there. We aren't near that point yet, but it's not practical to set our minds in those terms. Starship has flown. It has not flown to orbit. "BFR"/Superheavy Booster has not flown, and it is a huge hurdle to cross. A lot of engineering has to go right to make it work, but they can do it, maybe not on the first few tries even, but just like Falcon 9, it can be done. Heat shields and refueling can and will be done too. As for NASA looking for a way to gracefully extricate themselves from Artemis, I'm pretty sure that SpaceX doesn't really care. They have their $2.9B for development of a heat shield, orbital refueling, and Superheavy launch capability. All of that takes them closer and closer to Mars, which is the goal. The Moon is not SpaceX' goal, Mars is. Nothing else. To the extent that Artemis assists them in reaching that goal they will participate in Artemis. If Artemis ends, or they lose a future contract, they will continue on their own toward their goal.
_________________ My last name rhymes with 'geese'.
|
|
Top |
|
Username Protected
|
Post subject: Re: Starship & Moon Landing Complexity … Posted: 15 Aug 2021, 12:56 |
|
|
|
|
|
Joined: 04/26/13 Posts: 19944 Post Likes: +19685 Location: Columbus , IN (KBAK)
Aircraft: 1968 Baron D55
|
|
Username Protected wrote: Musk is beginning to equivocate WRT reusable. What is cheaper and/or lower risk? 16 reusables vs. four expendables?
Beats me … What makes you say that he's equivocating on reusability? The only thing that SpaceX throws away is the Falcon 9 upper stage. Starship and Superheavy are both designed to be fully and rapidly reusable.
_________________ My last name rhymes with 'geese'.
|
|
Top |
|
Username Protected
|
Post subject: Re: Starship & Moon Landing Complexity … Posted: 15 Aug 2021, 16:41 |
|
|
|
|
|
Joined: 12/22/07 Posts: 12893 Post Likes: +13315 Company: Midwest Chemtrails, LLC Location: KPTK (SE Michigan)
Aircraft: C205
|
|
Username Protected wrote: Musk is beginning to equivocate WRT reusable. What is cheaper and/or lower risk? 16 reusables vs. four expendables?
Beats me … What makes you say that he's equivocating on reusability? The only thing that SpaceX throws away is the Falcon 9 upper stage. Starship and Superheavy are both designed to be fully and rapidly reusable. Incomplete. Re-use vs. expendable depends on the mission.
Musk has stated that they are considering four expendable Starships vs. 16 repetitive launches of N-reusable Starships. He specifically cited the possible benefits of trading away the weight of the thermal protection tiles, articulating wings and landing/capture gear … for more payload mass to orbit in fewer (he said four) launches.
_________________ Life is a DiY project.
|
|
Top |
|
Username Protected
|
Post subject: Re: Starship & Moon Landing Complexity … Posted: 16 Aug 2021, 12:34 |
|
|
|
|
|
Joined: 04/26/13 Posts: 19944 Post Likes: +19685 Location: Columbus , IN (KBAK)
Aircraft: 1968 Baron D55
|
|
Username Protected wrote: Musk has stated that they are considering four expendable Starships vs. 16 repetitive launches of N-reusable Starships. He specifically cited the possible benefits of trading away the weight of the thermal protection tiles, articulating wings and landing/capture gear … for more payload mass to orbit in fewer (he said four) launches. I missed that, but if he can drop the number of launches by 75% that's a heck of an improvement. I'd be tempted to equivocate too. That said, I struggle to imagine that the heat shield tiles, and flaps would yield a 75% increase in payload to orbit. There is no landing gear on the current Starship, and the "capture gear" is mostly on the tower.
_________________ My last name rhymes with 'geese'.
|
|
Top |
|
Username Protected
|
Post subject: Re: Starship & Moon Landing Complexity … Posted: 16 Aug 2021, 12:57 |
|
|
|
|
Joined: 01/06/08 Posts: 4701 Post Likes: +2703
Aircraft: B55 P2
|
|
With rockets you are fighting an exponential in the fuel mass. So modest reductions in weight can make a big difference. (the above is assuming you are not also scaling the size of the fule tanks etc - depends on the assumptions)_ Username Protected wrote: Musk has stated that they are considering four expendable Starships vs. 16 repetitive launches of N-reusable Starships. He specifically cited the possible benefits of trading away the weight of the thermal protection tiles, articulating wings and landing/capture gear … for more payload mass to orbit in fewer (he said four) launches. I missed that, but if he can drop the number of launches by 75% that's a heck of an improvement. I'd be tempted to equivocate too. That said, I struggle to imagine that the heat shield tiles, and flaps would yield a 75% increase in payload to orbit. There is no landing gear on the current Starship, and the "capture gear" is mostly on the tower.
|
|
Top |
|
|
You cannot post new topics in this forum You cannot reply to topics in this forum You cannot edit your posts in this forum You cannot delete your posts in this forum You cannot post attachments in this forum
|
Terms of Service | Forum FAQ | Contact Us
BeechTalk, LLC is the quintessential Beechcraft Owners & Pilots Group providing a
forum for the discussion of technical, practical, and entertaining issues relating to all Beech aircraft. These include
the Bonanza (both V-tail and straight-tail models), Baron, Debonair, Duke, Twin Bonanza, King Air, Sierra, Skipper, Sport, Sundowner,
Musketeer, Travel Air, Starship, Queen Air, BeechJet, and Premier lines of airplanes, turboprops, and turbojets.
BeechTalk, LLC is not affiliated or endorsed by the Beechcraft Corporation, its subsidiaries, or affiliates.
Beechcraft™, King Air™, and Travel Air™ are the registered trademarks of the Beechcraft Corporation.
Copyright© BeechTalk, LLC 2007-2024
|
|
|
|