Ark-Class is a designation assigned to United Federation vessels that are operated by the Navy and belong to the 35th Preserveration Fleet. Ark-Class vessels rival Massive-Class starships in size, and typically hold the capacity of at least 5,000. A multitude of Ark-Class vessels have been produced and stored in underground facilities on Mars, specifically to be prepared in the event of a planetary emergency that required the mass evacuation of the population.