Jeff Bezos is right

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Oct 23, 2019
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It's a fact that launching 10 Starships to get ONE mission is a gambling game (and Musk is a gambler). Provided the reliability of the moon mission has to be as low as 99,5%, each rocket must have a reliability of 99,995% . I don't know ONE type of rocket of such a reliability. I wouldn't bet on the Musk solution ;)
I think NASA will has to acknowledge the normative power of the factual and the gambling game will end better sooner than later.
 
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It's a fact that launching 10 Starships to get ONE mission is a gambling game (and Musk is a gambler). Provided the reliability of the moon mission has to be as low as 99,5%, each rocket must have a reliability of 99,995% .
Well, they could launch 11 if one fails, right? Perhaps an extra ship will be orbiting Earth in case of emergency needs.
 
Aug 8, 2021
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For Spacex, if they can have an Artemis variant ready, they will be even readier for a test flight to Mars for the q4 2004 Mars window, as the fitout for these versions would not be as complex like the manned Artemis version (not until later this decade when there are manned missions to Mars). That being the case, there will be multiple ships sent to Mars in that window, as they are attempting to build a fleet. I'd presume that they'd be dropping off cargo and any science missions needing a lift, as they need as much cargo sent as possible in advance of manned missions (so not sending 1 ship) and to test unknowns like fleet operations, plus for redundancy reasons (miserable if you send 1 and that fails, you can't test a return to earth missions for another 2 years).

I might be putting 2+2 together and getting 5 as an answer... But I thought that Spacex was going to be making some Tankers, to reside up there in orbit, fuelled up and ready. If they have tankers in place for Mars launches, for the Artemis variant, it is effectively one launch plus 1 refuel at a tanker.
 
May 11, 2021
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It's a fact that launching 10 Starships to get ONE mission is a gambling game (and Musk is a gambler). Provided the reliability of the moon mission has to be as low as 99,5%, each rocket must have a reliability of 99,995% . I don't know ONE type of rocket of such a reliability. I wouldn't bet on the Musk solution ;)
I think NASA will has to acknowledge the normative power of the factual and the gambling game will end better sooner than later.
That is not an accurate description of the situation. If SpaceX continue at their current pace, a single starship failure would not result in the loss of the mission. The cadence of Starship launches is expected to be very high there would be plenty of spare ships, boosters and even launch sites by 2024. NASA awarded SpaceX the contract because it was the only possible choice with the finances available and because it met all requirements. The others were unaffordable and technically lacking on multiple counts.

The problem is Jeff Bezos is a sore loser and has posted a load on nonsense and half truths about the SpaceX offering whilst failing to address the problem with the BO offering. Musk replied to his tweets saying that 4 re-tanking missions would probably be enough. Despite all this and the rejection of the Bezo’s complaint by the Government Audit Office he’s now trying to sue NASA. When what he should be doing is getting his house in order and actually getting a Blue Origin rocket into orbit.
 
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Oct 23, 2020
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It's a fact that launching 10 Starships to get ONE mission is a gambling game (and Musk is a gambler). Provided the reliability of the moon mission has to be as low as 99,5%, each rocket must have a reliability of 99,995% . I don't know ONE type of rocket of such a reliability. I wouldn't bet on the Musk solution ;)
I think NASA will has to acknowledge the normative power of the factual and the gambling game will end better sooner than later.
Yes, by launching so many spacecrafts in space in order to make only one space mission sounds a bit as a pointless idea. I cannot even imagine the amount of resoursess will be taken for that mission.
 
Aug 8, 2021
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Musk has stated that it might only need 4 refuel flights (Moon lander variant of starship is much lighter, doesn't need heatshields, flaps, much lighter leg structure as moon gravity is 1/6th). It is taking 100 tons, not 1-2 tons. For the other HLS systems to ferry 100 tons, that is 50 plus launches compared to launch of the lander plus 4 refuels.

The end goal of Artemis is a moonbase, this will require a lot of payload to be taken over time. Beyond the first bits of Mankind putting boots back on the moon, to build a permanent base means NASA requires a next step multibillion dollar tender to ferry large amounts of materials and more frequent missions - Starship already does this for them and does it cheaply.
 
Aug 6, 2021
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One could compare the Apollo spacecraft with SpaceX's Starship plus Superheavy, since SpaceX's Starship plus Superheavy is the only launch vehicle plus space craft within the Apollo size range. Apollo was a three-stage rocket; SS+SH is a two-stage rocket. Apollo threw most of its structure away, once it had been used; SS+SH doesn't. And last but hardly least, refueling in space is yet to be conquered. But it was one of the things the likes of Arthur C. Clarke considered, since for example, his Discovery in 2001: A Space Odyssey would've relied on it to get its tanks filled. The major thing to wonder about is, why it has taken so long following Apollo, to get this far.

As far as Jeff Bezos and Blue Origin goes, the sooner he gets his A into G and starts showing something more serious than a mere suborbital hop, the better. It seems the only real competition Elon Musk and SpaceX are facing, comes from RocketLab, because Peter Beck's not resting on his laurels: I expect Neutron to be as big a game-changer as Electron was.
 
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One could compare the Apollo spacecraft with SpaceX's Starship plus Superheavy, since SpaceX's Starship plus Superheavy is the only launch vehicle plus space craft within the Apollo size range. Apollo was a three-stage rocket; SS+SH is a two-stage rocket. Apollo threw most of its structure away, once it had been used; SS+SH doesn't. And last but hardly least, refueling in space is yet to be conquered. But it was one of the things the likes of Arthur C. Clarke considered, since for example, his Discovery in 2001: A Space Odyssey would've relied on it to get its tanks filled. The major thing to wonder about is, why it has taken so long following Apollo, to get this far.

As far as Jeff Bezos and Blue Origin goes, the sooner he gets his A into G and starts showing something more serious than a mere suborbital hop, the better. It seems the only real competition Elon Musk and SpaceX are facing, comes from RocketLab, because Peter Beck's not resting on his laurels: I expect Neutron to be as big a game-changer as Electron was.
The reason why it has taken so long is because the vast majority of the political critters are simply not interested in space exploration. Some will give fine speeches about America's role in exploring space etc but they are not really engaged. Even president Kennedy didn't care about going to the Moon except as a means to demonstrate American superiority over the Russians to the world during the cold war.

Money still needs to be spent on space to demonstrate on going American technological superiority, support the military etc but the real driver is now jobs. That is why we have the utter nonsense of SLS, cost plus contracts and the tailing wagging the dog as members of congress try to manipulate the goals of the space program to ensure that the big aerospace players in their states get a slice of the action.

Nobody imagined that SpaceX would put in such a low bid for the HLS or that a stand in NASA administrator would make the bold decision to prioritise something that could actually be afforded in the timeframe given. Such beautiful irony.
 
Sep 11, 2021
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Yes, by launching so many spacecrafts in space in order to make only one space mission sounds a bit as a pointless idea. I cannot even imagine the amount of resoursess will be taken for that mission.

It's easy to image the amount of resources when SpaceX's bid was half of Blue Origins, and delivers nearly 50 times more payload to the moon.

The reason is that SpaceX is using in-orbit fueling and a fully reusable launch system, while BO is relying on expensive old space launch systems without the cadence to support in-orbit refueling. Remember that Werner Von Braun actively preferred in-orbit assembly (the close cousin of in-orbit refueling) for the original moon landings, and only abandoned it because of the perceived risk of mastering assembling the lunar ship in their short time-line to the moon.

That was 60 years ago. In-orbit refueling is far simpler than actually assembly, and when mastered opens up the entire solar system to manned exploration. Starship is designed to have a high cadence, allowing a series of tanker flights to refuel the HLS in low earth orbit over a few weeks. If one tanker flight fails, no worries, another will be ready in a couple days. It's actually far lower risk than BO's plan which fails utterly if any launch fails.

NASA chose SpaceX because their design makes sense, and is the way out of the it's 50 years of handcuffs caused by expensive low cadence launch systems. Perhaps SpaceX will struggle to master in-orbit refueling leading to delays, but that risk is well worth taking. If NASA chose the Blue Origin lander all Artemis could become is a newer version of Apollo with an increase to 5 tons of payload , and likely fewer manned missions given it's expense. It's only going to be able to land a pair of astronauts restricted to a lunar day (at most 2 weeks, likely far less). They'd do similar moon walks, ride a simiilar moon buggy and return, same as Apollo.

SpaceX HLS has a 100 ton payload capacity, 20 times more! That's what in-orbit refueling gives you. It can land components to build a lunar base for dozens of astronauts, and the supplies , equipment and power storage necessary to last through lunar nights for a full time research presence lasting months or years. Not just short buggy rides, but exploring far across the lunar surface for hundreds of miles and beneath it for resources. Even visiting polar ice caps for ice.

We should absolutely wait to return to the moon until we have the capabilities to stay for the long run and do the exploration and experiments to answer all the scientific questions we've had since we left 50 years ago. Don't blow our limited funds on a pale Apollo clone and set back lunar exploration another decade.
 
Don’t know much about refueling in orbit. Haven’t seen any that done. From what I’ve seen, the fuel and vapor in the hard tanks, bubble’s of liquid and vapor kinda float around all over the place, sorta like a lava lamp. The combination of the tanker docked to the craft, the RCS would have to be inline with the center of gravity and would have to do a continuous ullage burn to transfer liquid. Or, the tank would have to be a balloon or bellows type collapsible tank with no vapor space. That just might be easier said than done.
 
Sep 11, 2021
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Don’t know much about refueling in orbit. Haven’t seen any that done. From what I’ve seen, the fuel and vapor in the hard tanks, bubble’s of liquid and vapor kinda float around all over the place, sorta like a lava lamp. The combination of the tanker docked to the craft, the RCS would have to be inline with the center of gravity and would have to do a continuous ullage burn to transfer liquid. Or, the tank would have to be a balloon or bellows type collapsible tank with no vapor space. That just might be easier said than done.

I believe they originally planned to dock the tanker and Starship/HLS tail to tail and spin them around the head of the tanker so a light centripetal force would help drive the fluid/vapor into the recipient's tanks.

Now I've read they've moved the connections to the head of the ships so they would dock them head to head, but still same concept I think.

Time will tell how well this works. In-orbit refueling and reentry shielding are potentially where the Starship project will suffer most of it's delays. Perhaps they'll need to add some other techniques to get a full transfer done in orbit.

But either way this is the future of space travel. Building a massive single rocket to carry all your fuel for a trip to another body and back would always limit us to tiny payloads. Being able to use high cadence reusable tankers to fully fuel a deep-space ship within a few weeks enables the massively larger crews and payloads you need for exploring the Moon, Mars, etc.

 
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That’s a great idea, it’ll keep the fuel at the free end. Then they would connect the transfer pump at that end, then vent the receiving vessel to accommodate the fuel.
 
May 11, 2021
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Don’t know much about refueling in orbit. Haven’t seen any that done. From what I’ve seen, the fuel and vapor in the hard tanks, bubble’s of liquid and vapor kinda float around all over the place, sorta like a lava lamp. The combination of the tanker docked to the craft, the RCS would have to be inline with the center of gravity and would have to do a continuous ullage burn to transfer liquid. Or, the tank would have to be a balloon or bellows type collapsible tank with no vapor space. That just might be easier said than done.
It is relatively easy to settle the tanks by firing cold gas thrusters. This tech has been around for a long time even Apollo used this technique. But AFAIK no one has ever attempted to transfer such a large quantity of cryogenic propellant in 0g before, however theoretically is should be very doable, it's just that no one has tired. The fact that it has never been done before is not an obstacle, SpaceX have done plenty of things that have not been done before but were theoretically possible, like recovery and reuse of faring shrouds. And plenty more things that have only been tested but not used in anger like the full flow staged combustion Methalox engine. I wouldn't bet against this working, in fact I would bet that it will work very well after they have tested it and sorted the bugs out.
 
“It is relatively easy to settle the tanks by firing cold gas thrusters”
Essentially ullage burn, it would have to be sustained throughout the fuel transfer evolution.
 

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