Complex sentence: He is still on the ship when it heads into the sun. Ford and Arthur arrive without Zaphod and Trillium on a spaceship carrying millions people in cryogenic pods.
Split into simpler sentences: He is still on the ship when it heads into the sun. Ford and Arthur arrive safely somewhere, but Zaphod and Trillium are not with them. They've been transported to a spaceship carrying millions people in cryogenic pods.