i just think it would be cool if you had CO2 and O2 balance you have to reach inside your ship that might limit the amount of people who can be on a ship. it would also have you have to return to the ship once in a wile to get air and it would promote the creation of ship yards where you can breath and build with no problem. the rate of oxygen consumption could be changed through difficulty settings and would encourage planetary starts to the game. in my opinion this is a much needed feature to the game and you could even make new player equipment like O2 scrubbers to improve away time