The HCS (Hyperspace Colony Ship) Gaia is the secondary Human Haven, though it is far larger than the HCS Jackson. While it only carries half as many Humans (5000) as its counterpart, the Gaia is responsible for bringing the second wave's equipment and supplies.
As the name hints, the Gaia is crucial to the success of the Horizons Initiative.
After the relatively easy time they had developing the first Human Haven, the Initiative figured Gaia would be much of the same, albeit on a larger scale. However, this was far from the case. As funding dried and constructing additional Havens seemed less and less likely, the Gaia was forced to be redesigned and consequently considerably scaled down: making its development take far longer as a result.
In the event that the Aether was lost or the second wave separated, the Gaia is equipped to carry on the Initiative's legacy, albeit much less effectively. Naturally, this responsibility made fielding a captain that much more important, leading to Mike Trainer choosing his former colleague and close friend Galen Antuma for the job.
Despite numerous setbacks, the Gaia departed the Milky Way on time on November 2, 2180 with the second wave.