Help me find books for my dad, who has only read two full books in his life.

Hello! My dad is 55 and will soon undergo a below the knee amputation due to a complicated injury that happened about 5 years ago. He will be spending a week in the hospital, 8 weeks in a rehabilitation centre, and probably a lot more time in bed at home after that. So, he needs something to do!
He recently read his first two books front to back, and finally understands how to enjoy reading! Very proud of him for trying. He has expressed wanting to read more books, but is unsure of what to try next.
The first book he read was Living with a Below-Knee Amputation by Richard Lee Riley, which gives multiple stories from real people about their experience with amputation. Its help him a lot with preparation, and he enjoyed the delivery of each narrative.
The second was An Astronauts Guide to Life On Earth by Chris Hadfield. He also really enjoyed this one, as we are Canadian and he loves space stuff.
I was thinking of getting some more space related books, perhaps another autobiography. But I also wanted to introduce him to science fiction. Since it would only be his third book, I don’t want to get him something too intense, complicated, or overwhelming, but still interesting.
Any suggestions?

TLDR: Dad will be recovering from surgery and needs books. Preferably autobiographies or science fiction. Space related, but easygoing. Other suggestions appreciated as well!