I am not sure if this was already suggested and if it was i am really sorry
....
Anyway, for those who don't know what space engine is this is their website:
http://en.spaceengine.org/My idea is to implement Outerra's engine into the one of Space Engine, what would happen, I think, is a massive universe on which every planet is "visitable" and has perfect details and physics. Of course this would mean expanding Outerra's textures server to also include textures for different planets.
Even a bigger idea following this would be a MMO game where you have a spaceship and you can travel through a vast universe in which you can land on different planets and explore, and stuff like that (I have many more ideas but it would take me too much to list them all)
Thank you for reading this and excuse some of the typos and grammatical errors, English is not my first language.
PS: my friend and I could volunteer in the concept art and possible 3D editing!