Bravo Fleet Planet Classification: http://www.bravofleet.net/bravofleet/pcs.html
Hot zone:
I - Class J (Geo-Morteus) - A planetoid rather than a planet, diameter of 1200 kilometres with scarce gravity, and high surface temperature due to the proximity to the star. The atmosphere consists of helium and sodium gasses. Incapable of harbouring life and in general suicidal to set foot on.
II - Class G - Desert planet that has a thin oxygen atmosphere and very limited water, most of it too deep to sustain any surface-lift. Inhospitable to everything but the most rugged of life-forms. Daytime temperatures approach 70 degrees Celsius, never dropping below 20 at night. Because of the planet's semi-habitable but inhospitable environment, it is used as a planetary testing ground for various sciences, among them medical research about dangerous plagues, and weapon's testing ground. Also used by Star Fleet as a special operations training ground.
Habitable Zone:
III - Class K - Since 2279 in process of being Terraformed to class M, with about 250 years, give or take a few decades, to go before being capable of independently supporting life. Has a light oxygen-nitrogen atmosphere, contains only the most basic of microbiological life and is (as of yet) uninhabitable. Three main research/control facilities located on the surface. 1 moon circles.
IV - Class N - Naturally habitable planet with 97% water surface, oxygen-nitrogen atmosphere, inhabited (colonised). 2 moons circle. [ More ]
Cold Zone:
V - Class A - The 5th planet in the system is a gas giant, akin to Jupiter. It has no solid form inside, but exhibits a great gravity well. It has 12 moons in sizes ranging from planetoid to satellites larger than 50000km diameters, the majority of which are ice and rocks mixed with frozen gasses.
VI - Class A - Slightly smaller than it's 5th twin, Bellatrix VI is a gas giant as well. It has 14 moons circling it.
VII - Class B - Bellatrix VII is also a gas giant, and has a turbulent history, nearly being broken apart by a meteorite several millennia ago. The rock was shattered, and today surrounds the planet in a semi-ring of broken shards that constitute a great navigational hazard.
Asteroid belt - Classified minor navigational hazard. Rather benign and predictable circle of rocks that constitute the planet 8th planet that never was.
Moons - [More under development....]