[Cynor]

Not sure if it fits or not, but what about "The Third: The Girl With the Blue Eyes" (talk about a mouthful) ? I believe it takes place on earth, but there was a space-y element to it iirc.

World Destruction probably fits too.

While not too serious, To Love-Ru has some of the elements you may like. Bit heavy (ok, pretty heavy actually) on fanservice though.

You should probably also look at Code Geass. Great series, bit of a sci-fi feel to it (mechs) with a good story. No real space portions though.

Stratos4 may also be worth a look. Can't remember the serious level, but it certainly has some sci-fi and stuff happening in/from space.