Deep blue symbolizes the highest parts of the sky. Generally 20km to 25km in the Earth's atmosphere.
The central symbol of a round shape being orbited by others symbolizes the movement of the stars, the orbital trajectories in general.
The text describes itself.
Ok, so there are three ranks. Team Titan is the start, involves a moon mission. Specifics go here: Team Titan Instructions! Then you can edit your posts for about 5 mins and a few other things. There is Team Frontier, aka the one I am in right now. You have to make a space station with 4 seperate launches(docking section, hab module, escape, and solar panels with a way to change orbit), a Mars return mission, then launching a supplied probe with a rocket+probe that most be less than or equal to 265 tons. Frontier specifications are here: Team Frontier Instructions! After that there is team hawk, the final one. Though that's complicated, look here: Team Hawk Instructions!