scripts not saving? did you use Ctrl+Enter or ESC to leave? When you press Ctrl the text area should be a bit grey, and then enter should save it.
=== SPOILER: ===
All you have to do is get the tank under the drone so you can inspect it from below. So you can:
left_forward -> it will turn like crazy
write right_forward but dont press enter yet. Wait until the moment it is facing the drone and hit enter. It will move forward towards the drone
type stop and wait the moment when it is under the drone to hit enter
once the minitank is below the drone, take a look around with the camera