Bardock is Goku's father and the only Saiyan who knew what was going to become of his planet being of his planet Vegeta, 

and its people. He was cursed with the ability to see the future, and saw glimpse of his planet being destroyed, as well as images of his son's life on earth. He makes a last stand against Freiza and tries to kill him, but of course his attempt is fruitless and he's killed by the biggest Death Ball Freiza ever created. But as he's dying he finally realizes that it's not him who is destined to defeat Freiza, it was his son. He talks to his son from the after-life while little Kakarot is on his way to earth and 

chares him with the task of killing Freiza to avenge his father, and the rest of the Saiyans.