Lunar lander discussion

Ship 31 nose cone stacked?!





9/2/23: Update to post of 7/11/23:

The markings of this indicate that it's an HLS ( lunar lander) mockup. But what if you made a lander of this size, as opposed to the entire starship? The idea would be to reduce the weight of the lander. It would need less fuel to land, and to return to space. It's still pretty large, though.

Ship 31 as an HLS mockup

Original post of 7/11/23:

How many launches will it take to get the Starship lunar lander to complete its mission? Elon Musk says four. Jeff Bezos says sixteen. Perhaps they are both exaggerating for effect. It does make a certain amount of sense to say that it would take only four.

Musk says that the lunar lander will weigh a lot less. It takes upwards of 50 pounds of fuel for each pound that gets to orbit. That's just fuel. Running the numbers a bit, it take 6000 tons in order to get 150 tons into orbit. That about 4800 for the booster, and 1200 for the Starship. So maybe you can do it for forty pounds instead of fifty.

The Artemis mission doesn't require a full 150 tons to the lunar surface. That helps. The Starship doesn't need fins and a heat tiles because it won't re-enter the Earth's atmosphere. That helps.

The question is how much does this thing weigh? Also, would it be desirable to cut the weight even further? What if it were detachable? What if the cargo and crew section were to be made of a different material, like aluminum? Or carbon fiber? Musk doesn't plan on making hundreds of these. It's a one-off. He may need to make only a few of them.

The Apollo program had only a 15 ton lunar lander. Most of that was hardware and fuel. You can make that a baseline. The Starship may have an empty weight of 110 tons or more. Would it make sense for Musk to shave the weight down a bit more, or a lot more?

We'll see. But it probably won't take fourteen launches. As it stands now, it will probably take more than five.

There are other ways of doing the mission. For instance, let's say that the Starship cargo and crew area were to be used for stowing a separate lander. Perhaps you could use the Dragon variant with a fuel tank attached. The Starship could be refueled enough to get to the Gateway, and back to Earth orbit. It could be reused for future missions. It's role would be a tug. The lunar lander will take the crew and cargo the rest of the way and back to the Gateway. The Orion will get the crew back to Earth.

The Starship can put 150 tons into low orbit. The Artemis mission doesn't require 150 tons on the moon. It would appear to have some extra capacity not being used. The delta-v required would have to be less than what it would take to get to Earth orbit. Therefore, if enough delta v were available, 150 tons could be sent to the Gateway. This would include the lander and all its fuel. If the lander massed out at less than 150 tons, the Starship can get it to Earth orbit. Would 150 tons be enough to get a lander on the surface and back to the Gateway? A hunch would say that this may be feasible.

We'll see how it is done. Musk has a contract, and he wouldn't want to lose money on the deal. If it is worth it, and he can keep it within budget, who knows? It may be a lot simpler to do it the way he seems to be doing it. It doesn't seem very elegant to me though.

Another thought here: it could be in the contract, and therefore, it is already set. There's no chance to make design changes, in other words. Too bad, if that is the case.