No matter the end you get, you see Joker and the Normandy's crew escaping the explosion caused by the Crucible. He later crashes on a jungle planet and, under some circumstances, you could see him getting out from the Normandy along with some of your squad members. The sky they see after crashing seems to indicate they landed on the moon of a Jupiter sized planet.
Correct me if I'm wrong, but this planet should be outside of Sol's system and they cannot reach a system with a habitable planet within a matter days, or hours in the best case scenario. Thus this means the Normandy used the Charon Mass Relay before it exploded.
How did Joker and the surviving Normandy crew members end up that far from Earth, the battle, and Shepard?