The Reagan was a supercarrier.
At Doran Routhe's private laboratories on Earth, the Reagan was loaded with thousands of United Powers League prisoners and enough supplies, rations and hardware to aid them once they arrived at their destination.
The Reagan was programmed to follow the Nagglfar as it was launched toward Gantris VI. At some point during the voyage the Reagan veered off course along with the other supercarriers and barrel blindly through warp space for twenty-eight years until its warp-drive engines reached critical meltdown.
The Reagan emerged into real space in the Koprulu sector. With its engines destroyed and its life-support batteries nearly exhausted, the Reagan engaged its emergency protocols and landed on Umoja. The 'cold sleep' chambers were then deactivated and the passengers slowly awakened. In an attempt to find refuge in their new surroundings, they stripped the Reagan of essential materials.
"Reagan" is a league name in StarCraft II.