I like that you're continuing this story. I think you can get a lot out of it. The theme lends itself to good development. I'm struck by how Evan only calls his friend Sam and not someone closer to him, which may indicate that he has no family and perhaps that is one of the reasons he was selected for this mission. Likewise, his closeness to his neighbor tells me that he is nice, but he is a lonely boy.
I loved it, as always. Keep writing and don't go to Mars. Hahaha. Hugs.