The U.N.S. Unity was a starship used to take human colonists to the Alpha Centauri system. From the beginning, there were problems aboard the Unity. An unexpected reactor malfunction damaged the ship, waking the travelers early from cryo-sleep. It was soon evident that the accident has damaged the communications equipment and contact with Earth was lost, and couldn't be re-established. The leadership of the mission was faced with the prospect of going it alone and soon begin to argue obstinately about the best way to proceed. Each game begins when the Unity Mission reaches Chiron, by which time the mission has fallen into chaos. Had the Unity not suffered a reactor malfunction, it could have been used as an ark ferrying what remained of humanity to Chiron.
The wreckage of the U.N.S. Unity can be found on planet, where the Unity units can be retrieved. These lightly armored units can be useful for early exploration.