This is a collection of sci-fi short stories. Most of them are formulaic, but it's a formula that works: there is some new or unexplainable phenomenon, scatter-brained physicist (McAndrew) and the narrator (spaceship pilot) go off to explore. McAndrew does something stupid and puts himself in danger, but he and the pilot overcome the adversity through cunning and/or scientific knowledge.
All of the stories have a little bit of a different twist, and it's enough to keep them interesting. The book is an easy read, and was definitely enjoyable. All of the stories were originally published separately, which I think would have made the pattern less obvious -- reading them together makes it stand out. That's the only minor drawback to an otherwise really good book.