Space

Oh, thats not enough pure stuff/people to the Moon? We want more stuff getting to the moon and back in each go?

Ok, first send up basically an analogue of a CSM with docking ports all over it.

Then send up two cargo modules and dock them symmetrically to the psuedo CSM. Then send up a translunar booster, then send up two lunar modules with crew.

Now you have a stick with roughly a wheel on one end of it.

)--===-|o

)-- is the translunar rocket module

=== is the CSM

(its not the 1960s so it can deploy solar panels and thermal radiative panels radially as well)

-|o

is the initial docking node thing that looks like a + when viewed head on, and its got two symmetrically connected cargo landers, and two symmetrically connected human landers.

the o is your return crew to earth lander, either send that up along with your docking node thing, or another flight if it wont fit all together.

Send this all to LLO, keep the CSM in LLO, drop off your people and cargo, do stuff on the moon, send the cargo landers and human landers back up to the CSM, go back to LEO, crew gets in the return lander, goes home, CSM and translunar engine stay in LEO.

Now, send up a maintenenance crew in a dragon capsule, along with some supplies, they check out the CSM and translunar module and make sure its all good, ready to be reused.

If it is, ok now send up some refuelling capsules and manually refuel, EVA if you have to.

Now you have what is functionally a translunar tugboat, that can be reused for a while, and modularly refitted with supplies, crew, lunar cargo and crew modules, earth return modules.

Now I am not saying all this is easy or guaranteed to work, but... why has Musk spent a decade chasing this giant mega rocket scheme, when he could have been ... just attempting a more modular system like this, that he and clever engineers could figure out how to do with ... probably not entirely, at least initially, but vast majority mostly recoverable and reusable rocket launches to LEO, and possibly even partially reusable two stage lunar cargo and crew modules?

(Just send up some new landing modules for the bottom half of the lunar cargo/crew modules and maintain and refuel the lunar ascent engines)

You could do some kind of configuration of modular parts in LEO as defined by the Falcon Heavy's LEO launch capacity and how reusable vs how many components, how much assembly time you need... and just make a, or possibly many just modular lunar tugboats like this.

Everything could also be tested, one segment at a time, instead of testing the whole thing at once and basically losing everything on any failure.

Everything other than in orbit cryogenic refueling has already been proven possible to do by other people, other organizations.

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Now getting humans to Mars is a whole other story, but again, you could use a modular approach to assemble essentially a big boy version of this concept, but it would be more complex and difficult... you're gonna need beefier martian lander/return modules, more LEO modular assembly required ... but this way, you have construction happen either directed remotely or with mainteance crews, then you stock up on supplies and fuel, then you send people... and this is way more efficient in the long run as you dont have as much fuel boil off and martian bound crew just eating 3 to 6 months of rations and water while waiting for all the refuelling tankers to reach them, as is SpaceX's current approach.

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