I found Packing for Mars very fun and mildly informative. Great bedtime reading. Based on the title, I thought it would be more about the specific challenges of crewed flight to Mars, but instead it’s a more general discussion of the practical difficulties of human spaceflight, more heavily weighted toward the Mercury, Gemini & Apollo programs. I detected no physics/astronomy blunders. Lots of mind-boggling facts, and hearty guffaws.