If a player falls below height level 35, they will be teleported to the Earth the same way they could leave it using the rocket.
There are 2 possible ways to leave space station.
If you want to live on your space station for a decent amount of time, you need to set up either an oxygen system on the station, or a large cache of oxygen tanks. Necessary Items Required (To Create Space Station) This command is the exact opposite of '/ssinvite', meaning it removes selected player from the list of players who can access the base. However, despite the fact that command says '/ss invite', the invited player can get into that station the same way they can access other planets. This command allows the owner to add players to their space station. Adding/removing players Adding Players: /ssinvite