Odyssey

The Odyssey was the first Human colony ship. It colonized the worlds of the inner colonies. It was laden with troops and terra forming gear—spearheads the colonization of a new world. This sparked the first wave of human expansion beyond the confines of the Solar System. It was launched on January 1, 2362.

Sources

1. http://www.xbox.com/en-US/games/h/halo/storyline.htm - Xbox.com Backstory