I own a private server with Galacticraft and other mods. Both of us have gone to every planet available in the mod. But we've had limited resources until a while ago and we struggled to get both of us on the moon and Mars. So I'm suggesting rockets that could hold 2 or more players. Of course the rocket would have to be bigger to hold both players and would need more engines to not be terribly slow. I don't know what else to put here so I'm just going to stop writing now.