Ratchet's ship was a homemade design that Ratchet built on his homeplanet Veldin from pieces of scrap. Without the use of a robotic ignition system, however, the ship remained immobile.
When Clank crashlanded on the Kyzil Plateau, Ratchet finally got his ship to take off. However, he promptly crash-landed it on Novalis, and was forced to find a new one.
According to concept art unlockable in the first game, Ratchet's ship was supposed to be a "real homemade job held together by gum and rubber bands". According to the concept art description, it is not clear why Ratchet crash-landed the ship so early on in the game.