How did halo 1 end?

On the last level of Halo 1 You are on the Pillar of Autumn where it crashed on the halo. Spartan 117 uses a warthog to drive to the other end of the pillar of Autumn and escape the ship. The problem is that the flood infest the Ship so driving is difficult and the ship is exploding. At the very end he reaches a blackbird ship and pilots out.