Dragonball Kai episode 21

Description : Protect the Dragon Balls! The Namekian Offensive / Protect the Dragon Balls! The Namekians' All-Out Attack! Goku arrives at Capsule Corp. where Dr. Briefs has prepared a spaceship for him to travel to Namek in six days, as well as train. Goku begins to train at 20x Earth's gravity as he takes off for Namek. Meanwhile, the Namekians begin to fight back against Frieza's men, however Zarbon proves too powerful. Discovering that their people are being located via their scouters, the Namekians destroy the scouters. Dodoria filled with rage, rushes into the fray to make the locals regret the day they ever crossed Frieza.