The over-c is a drive technology capable of travelling higher speed than the speed of light. It was discovered accidentally, and, to this day, no-one fully knows how it works.
In 2227, a group of scientists investigating unstable sub-atomic particles discovered a way to break the speed of light. However, the experiment went disastrous, as the over-c drive proved to be unstable near a large center of gravity and caused a nuclear blast. However, the data from the experiment were stored in databanks far away, so they were recovered and their project became known. The development of the first over-c drives began what led to a practival form of interstellar travel.
A ceremonial plaque commemorating the accident was placed next to the crater.