The best known cryo trays and the ones usually referred to in context were those used by the Mothership Fleet during the Exodus to Hiigara. Volunteering themselves to be frozen as early as twelve years prior to the expedition, these Kushan colonists are people who have bought, earned, or somehow else attained a ticket for the first journey to Hiigara. These people, who were thought to simply be extraordinarily rich or adventurous turned out ironically to be the only remnants of the Kushan people other than the actual Mothership Fleet's crew by the end of the Homeworld War.