Reusable rockets optimize for cost while sacrificing total launch capacity. They need to reserve fuel to land. They don't get to put all of their fuel into laun

Reusable rockets optimize for cost while sacrificing total launch capacity. They need to reserve fuel to land. They don't get to put all of their fuel into launching their payload. They're great if you're doing commercial launches and making margins. They're less great if you're trying to launch a large mass a long distance. SpaceX is betting on in-orbit refueling for getting Starship anywhere but low Earth orbit. They have yet to demonstrate that capability, even between two Dragon capsules. So the Starship is not a guaranteed vehicle for any missions NASA wants to run.