There are only 3+1 `spaceflight` , and 4 `astronomy` . Neither seems dominant. I would suspect some `=aerospace` may be mainly space-related, and obviously many aviation ones don't have a spaceflight showcase. So it doesn't perfect fit either. 
`=aerospace` has been mass added before https://taghistory.raifer.tech/?#***/museum/aerospace
I don't understand how "space" would be misunderstood? 