english: You use gravitational flybys, slingshots, where you pass by a planet at very low altitude, a few thousand kilometers, and then you get the velocity of that planet around the sun for free.
non_english: Koristite gravitacione manevre u kojima prolazite pored planete veoma nisko, nekoliko stotina kilometara, i onda dobijate besplatno ubrzanje oko Sunca od te planete.