[mjevans]

Not for astronomy only; one customer among many.

SpaceX and trailing competitors are trying to make it cheap enough to get stuff out of the gravity well (including people and our more advanced products) that more permanent installations other places can get started. Elon says Mars a lot, probably because it's popular with the public. It's still expensive to send things up a gravity well, even if it's less expensive. The moon is shallow by comparison, and the asteroid belt far away but barely a dip. It would be safest to send robots first, bootstrap an installation that can manufacture local propulsion of any sort, O2, water, maybe even refine useful building materials, metal, or other resources. Anything so less is sent up.

Hopefully among all those things would also be materials to make large mirrors (optical and other portions of the EM spectrum), in less gravity, where it's cheaper to move them to useful areas of space, or even just truck them to spots around the surface of the moon.