The space domain is still way above people's heads. While the aerospace sector is booming, (I have AerospaceTV.com) the vast majority of money for space exploration still comes from governments so there is not much of a domain game there.
Space startups are growing in numbers so there is some play there, but Elon Musk gets most of the air in that market... and much of the big pay-off stuff, like asteroid mining, is so far off domains in that arena will mostly be stagnant assets for years to come.
Of course, the space changes overnight when Aliens are discovered. That will likely come sooner than later... with the new AI tools now searching the skies and combing through old and new data.
Will AI discover AAI? (Alien AI).
Its the mystery and endless speculations about space that make it a worthwhile domain game for those with active imaginations and a few bucks to spare. (I have ExtraterrestrialTV.com for fun and profit).