I think that !space is the most general community, and communities like “!astronomy” and “!spaceflight” are subsets.
Interesting data from a telescope? Astronomy and space, but not spaceflight.
A new GPS satellite is launched? Spaceflight and space, but not astronomy.
The Perseverance rover drills into a neat rock on Mars? Space, but not really astronomy or spaceflight.
A new space telescope is launched? Definitely all three.
These are just my thoughts though, and I’d love to hear what others think.
@Bee, @otter, @Bitswap Thoughts on changing the display name of !space from “Space & Astronomy” to just “Space”? Not that astronomy posts wouldn’t be welcome, but it could help reduce confusion with this community.