Dragon's Egg by Robert Forward. Hard SF at it's best written by an actual scientist. Do yourself a favor and seek this book out, you will not be disappointed as it is both a delight and fascinating.

(Having recommended the book I'm now concerned that a modern reader might find it sexist or racist or one of the other labels that woke culture is so happy to throw out dismissively when a work of art does not match their current world view. If you're going to read it but not be willing to accept that the world and accepted sensibilities were different 40 years ago then do us all a favor and don't read it. It you can't look past your limited world view to enjoy something just for what it is then please spare us all.

To be clear I'm not saying the book is blatantly sexist or racist or whatever, but it is common for older works to feel like they are to the modern eye)