342H: A Moon Boy’s Android Brother

I am hoping you can help me find a book from my childhood. I think it was from the early 80s to mid 90s. It was about a boy that gets an Android robot for a brother. I think they live on the moon in the future. I think one of them has red hair. I believe it was a kid’s series, I was between 10-14 when I read it. I could be totally wrong on how old it was. I think I read the book in 2000 so it could be 1990s too. But I remember the two kids are climbing a tree in it, and I think they were around 12, and lived in a dome on the moon. Again, not sure about this one. I think there were 2 or 3 books in the series.
Thanks for the help!