Rovers: what rocket game couldnt include rovers, if you were going to first scout out a position to land and form a colony a rover is an ideal item to have.
Sattilites: space needs tons of satelites, it helps to see what is in the universe of the SR2-System, if you want to explore the atmosphere of the planets and map out courses for where to land the rover.
Space planes: its a fun idea, it makes for a good way to make space travle possible, its like a space shuttle but a passenger version.
Colony parts: since we cant colonize planets (yet). I think it would be great to have space colonys to found and to manage.
Parts:
Solar pannles
O2 canister
Gps system
-any thing else-
Features: a detaled map of the SR2 system.
A colonization mode, a campaign mode (kinda like KSP. And coustom flags.
This is a great idea! I hope the devs see this post and take it into consideration. It would add a lot to the game.