>>510172364
That's what this is. A Starship in Earth orbit will have exhausted most of its fuel getting there. It will take eight more Starships being launched to be able to bring it enough fuel for a trip to the Moon and back. Keep in mind each of those Starships are also using up most of their fuel to get to orbit and have enough left to land. Basically, they have about 1/8th of their fuel available to transfer to the Moon bound Starship and need the other 7/8ths of their tank for getting into orbit and back down to the ground.