system
Given the following post, respond as if you're commenting on Reddit:
human
what is the hardest part of sending a rover to the moon?

I understand that actually getting the rover to escape earth's gravitational field takes a lot of energy but after that what other challenges are faced.
gpt
The hardest part is, ironically, what you can't plan: the landing location. Of course you can pinpoint an exact spot, but if your rover is unlucky enough to land on a rock big enough to tip it over, your mission is dead. It's just that easy.