This is a book about the Magellan mission, whose purpose was to gather topographical/geological data about Venus. I wanted to read it since a while ago (because of this recommendation), but I sort of gave up on reading it, since it is not available as an ebook, and there seems to be no way of getting hold of a physical copy, from where I live at least.

But after a while I thought of checking the Open Library of the Internet Archive, and lo and behold: there it is. You must use their in-browser reader, and you are reading scanned pages, but despite that, reading it that way (using a tablet) is not a bad experience. Except for having to be connected to Internet to read it, sighs. But that's not the Library's fault. Anyway.

The book presents a good overview of the scientific process around the mission: the history/previous efforts to map Venus, both from Earth observations, and Soviet and American probes. It also presents the scientific team (mostly geologists, and geophysicists) that receives the data, and provides a good overview of their analyses, the different hypotheses used to explain the geological features of Venus, etc., with a nice peek into the social process of the construction of this knowledge: the in-fights, ego clashes, squabbles for resources/recognition, etc.

You will have to go and get yourself a basic geology vocabulary (lithosphere, asthenosphere, plate tectonics, that kind of thing) to be able to follow those presentations. To me all of the geology stuff was somewhat dry but still interesting.

I think it's important to note here that the book has maps of the Venus areas discussed, in its final pages, so you can ground/relate them to all of the features discussed in those geological analyses; I didn't discover that until I finished the book, and it would have made my reading way more amenable. (This is where physical books have an advantage, I would have found that right away with a physical copy...)

Another main theme in the book is the mission from an engineering point of view: descriptions of the spacecraft, particularly focused in their computer systems, and of the operation of the spacecraft: all the work required to send and receive data between the spacecraft and the team, via the Deep Space Network, the work involved in processing the data and converting it into something a scientist can interpret, the spacecraft maneuvering and so on; also, of course, the handling of unexpected failures: the spacecraft control systems crashed (went into RPE, Runaway Program Execution) several times, provoking LOS (Loss Of Signal), and the book presents all of this in a detailed yet accessible fashion: what kind of resources they used to debug the issue, their hypotheses around the cause, the hacks they used to ameliorate it, and how they ended up diagnosing and correcting it.

Finally, the book is also about NASA project/mission management: building and launching a spacecraft requires a large effort, but keeping it running, analysing the data, planning/executing more operations with it, also involves a fair amount of effort and money, and even if a mission was approved, its budget for future years might go away, regardless of the spacecraft still being operational or not, and we get to see a bit of the managerial aspect of getting those resources: changes of plans/goals for the mission, optimizations from engineering, taking resources from "competing" projects, lobbying to your congressmen, people working for free, you name it.

It's quite an interesting read.

Also, if this book interests you, you might also be interested in Computers in Spaceflight: the NASA Experience: it's a book written by the NASA, about the computers they used in several missions, both manned and unmanned: the requirements around them, the technical characteristics of the computers, and their software and hardware architecture, and a little of the process of building the hardware and writing the software for the mission, particularly from the management point of view.