Leitos

Leitos is a Federation Penal Colony that houses most of the criminals in Federation Space.

Planet Information
Leitos is unique in the fact that it is one of the few worlds in Federation space that did not have a human population until after the Federation's foundation

Post-Invasion of Iphitos
After the invasion of Iphitos, the Federation found a need for housing for their criminals. While Colony Towers had more than adequate facilities to house any number of convicts within their own buildings, the obvious public discontent towards living near criminals necessitated the founding of an off-world penal colony.

Leitos, near the planet of Akorda, was a near barren, near airless rock. Sparse flora and fauna existed on the planet, but researchers stated that they could not be utilised for human consumption.

The most unique feature about Leitos is the fact that it is the only planet within all of Federation Space that does not house a Colony Tower. Instead, the prisoners live in artificially produced "bubbles" of oxygen. These bubbles regulate temperature enough so that working conditions are tolerable enough so that no complications will arise from hypothermia or other cold-related illnesses.

Naturally, the prisoners hold a deep-seated hatred of the Federation for the conditions they have been left in, however, revolt against the Federation is near impossible. Without Federation technology keeping the "bubbles" running, the prisoners die.