Dragon Ball Z - episode 36 - 13 Feb, 1990

The exhausted Goku, Krillin, and Gohan won their battle, and Bulma, Chi Chi, and the others arrive to help their friends. Learning of the death of Yamcha, Chiaotzu, Tien, Piccolo, and Kami, the Z Fighters are upset because without the Dragon Balls the others can't be wished back to life again, but Krillin has an idea. He recalls overhearing Vegeta saying that it was the Nameks who created the Dragon Balls, so they decide to go to the planet Namek. The only problem is that it will take 4339.2516 years to reach Namek. They decide to use Nappa's spaceship, because Saiyan spaceships travel much faster. (Source: Wikipedia)