Sorry for not replying sooner. I missed your response.

I've seen this idea before, and it's a mostly good one. I mean, yeah, there's obstacles, most importantly being how long the maglev track must be (since that would determine the degree of acceleration, which itself would determine what materials could be safely sent (and if living things like humans could be sent)).

Then there's issues like acquisition of miles and miles of property in a geologically- stable area, ensuring there's a no-fly zone near the exit point, and ensuring the security of the rail all along its length.

And how will it be powered? I could see a kilometer-square solar panel installation providing power to one of Musk's battery farms.

Oh, and will combustibles like rocket fuel be able to sent? One spark in the wrong place....

But those are mostly just details. The concept itself is rather sound and doable...given the political will.