firstly, in the intro movie, you will see a sleepership being destroyed(it stop flying forward and turn some degree around), and when the storyteller say they manage to break thru and the ship powerup the hyperdrive, only 4 left.
the "destroyed" ship is hispania, half of the crew escaped with emergency ships inside hispania and arrive to siruis about 50~100 years later. another half stayed with the ship and repair it until it is fly-able and reach sirius later.
the first half who escape with ship is the corsairs,
the other half who stay to repair the ship is outcast.
main source:planet crete infocard(f9), omicron gamma