When inventor Elon Musk lands in Springfield, he and Homer become fast friends and revolutionize the town's nuclear plant. But when Musk goes overboard and Mr. Burns wants him removed, Homer must figure out a way to break up with him. After they broke up, he went back to space with his space vehicle, in which he has a hologram of Homer and a big screen on which he plays The Simpsons: Tapped Out.
Elon Musk wants to change the world for the better, making energy more efficient. This is proven when he makes lots of changes to the Springfield Nuclear Power Plant, even though they would not only result in a loss of profits, but also Musk's preference for electric cars, although he burns a lot of rocket fuel according to Lisa Simpson.
Musk doesn't seem to make many friends and he doesn't do hugging, but he was surprised when Homer hugged him. Musk also seems to really value the friendships he does have, as he formed an emotional bond with Homer and when Homer told him that they could no longer be friends, he was upset. This heartbreak was so bad that Musk decided to create a hologram of Homer and watched over the town, although he thought that it was not the same Homer as the one he saw in person.