Centaurs were discovered by a ferret planetary exploration vessel, but they weren’t a spacefaring race when they were found– they were barely starting to use electricity and radio. 80 years after their discovery, centaurs continue to be a rarity off their homeplanet. Most spacecraft are not big enough to comfortably accommodate them, their medical technology is still playing catchup to the other aliens, and agriculture to feed spacer centaurs is spotty and expensive.