Earth has run short of water and arable land while the population keeps climbing, and the nuclear standoff has begun to read like a countdown. The United States looks to Mars for the resources that might carry everyone through. Rebuilding Mars to suit a human body would cost more than any treasury can raise, so the planners take the cheaper route and rebuild a human body to suit Mars.

Roger Torraway volunteered as understudy to astronaut Willy Hartnett, a role that promised training and not much else. The Man Plus program takes him anyway. Surgery follows surgery, reworking his senses, his skin, the systems that keep a man breathing on a world with no air to spare, and finally the mind that has to accept the new arrangement. Each stage improves his odds on the surface and subtracts something from the person his wife and his colleagues recognise.

Frederik Pohl writes the medicine with an engineer's patience and the politics with a colder eye, tracking the committee arithmetic that decides how much of a volunteer is spendable. The register is cerebral and unsentimental, closer to a procedural than an adventure, and the tension sits in the operating theatre rather than on the launch pad. It won the Nebula Award for Best Novel in 1976, collected Hugo and Campbell nominations, and placed third in the 1977 Locus Poll. Fifty years on it still reads as one of the sharpest accounts in science fiction of a body rented out to a national emergency.