This is a scifi manga with super advance tech but they cant find a single human on a planet. The AI should have been able to find him based on calculating the ships previous position from the planets previous position when pod was launched, then simulate how the pod would have decided on a landing spot. It was all run by AI, the AI can then use that to find where it would have gone... Lets not forget tracking high level communication frequencies his body and equipment would be giving off.