This is set in the "near future" of the 1990s(?) but is obviously written in the 70s in so, so many details. If you can take that in stride and view it as a "1970s Plus" alternate history, it's a fairly lean story with helpings of body horror and introspection on humanity. I actually wish it was a bit longer, namely in the end where they're actually on Mars, and hadn't attempted a whispy and clunky attempt at setting up a larger conspiracy because it didn't really pay off. Maybe if it was one of several books written back-to-back in a short series, but not in a book where the only sequel came out several decades later. Not sure I'll pick that up at all. I would like to read another author making a newer attempt at this book's concept, however.