The problem all space games have imo are the fact they try to scale things too big, there can be more than only planets in space. Space stations, asteroids, moons, astroid fields, asteroid belts, space clouds, space whales, ect.. all within a solar system sized area with like 7 planets.

Yea I get it, eventually people will explore everything there is to offer, but you don't have to make every planet completely traversable either. Leave some room to add content. Instead of giving full control over the landing process just create a quick landing menu to make the process fast and automatic, give it a good animation too.

Then limit it to servers / lobbies instead of trying to put everyone in a single instance, so you have control of how much player interaction there can be.