Supreme Commander Nick had afforded to design a ship capable of leaving this Galaxy and used that to travel into the Yuuzhan Vong Galaxy. The original idea was to investigate the Yuuzhan Vong, while in reality, they went to support the Predecessors against the Vong, as the Chiss were the only ones aware of the existance of the Predecessors. The Chiss were there during their jump towards the Vong Galaxy.