Definitely my favorite Baxter. Unlike most Baxter fare, there is no “big thinking”, no Xeelee, no looming destruction of the universe. It is, quite simply, a novel of what might have been (and very nearly was) if NASA had been allowed to continue in the footsteps of Apollo all the way to Mars. It is written in parallel perspectives, looking at the mission itself as it runs its course, and at the preparations, political wangling and engineering that precede it. The heroine, Natalie York, is followed closely as Baxter explores her long personal journey in parallel with the preparations, as it becomes clear to the reader (and to herself) just how much one has to sacrifice to become an astronaut. The quiet geologist becomes an astronaut and an unwilling hero as she reaches for the ultimate prize of both her professions. Despite being fiction, it is in my opinion one of the best portrayals of the culture and politics of NASA during the Apollo and post-Apollo era.
Baxter did in fact apply to be an astronaut. Unfortunately, he was required to speak a foreign language and thus failed to get in. In Voyage, his love of astronautics and space exploration clearly shows. If you liked the movie Apollo 13, you will enjoy this book.