that ship can transverse space and you dont think they could have built a power source for the robot?
According to Klaatu in the 1951 film, Gort holds irrevocable powers, and Gort demonstrates this when he first appears, reducing guns, turrets and even a tank to dust with a laserlike weapon that is projected from beneath a visor on his head, precise enough to destroy any object without harming anything around it. Is is stated that he had enough power to destroy the entire planet and is seemingly indestructible, and unstoppable against all of Earth's weapons, even atomic bombs. As the pilot and captain of Klaatu's ship, Gort can also operate highly complex machinery, just like the other members of his race which use similar ships to patrol planets. As his size would imply, Gort is also very strong physically, able to knock out men with a single blow.