We can all agree that Blackron and Ice Planet were one of, if not the best Space themes to every exist, I love them to death myself too.
I wanted though to talk about Spyrius, to me it's like the middle child of the Space theme. It is still loved, but quite a few people just seem to overlook it. Lego could've done alot with it, they could've built more onto the storyline and make it about a faction of baddies in stealthy ships that steal data and launch surveillance rockets and stuff. It was a theme that had potential for more sets.
That aside..we are lacking Space themes in this generation of Lego sets. Alien Conquest was a huge failure, and Galaxy Squad was meh (The only thing I liked were the massive bugs). Why don't we still keep up to the conflicts standards (Which I find a bit saddening, kids want fighting over exploration) and reboot Blacktron and Space Police, but keep it organic with simple designs and humans vs humans, (Aliens vs humans is getting old).