Mission to Mercury is a juvenile science fiction novel, the ninth in Hugh Walters' Chris Godfrey of U.N.E.X.A.

[1] The crewed expedition to Mercury is complicated by the fact that strong solar radiation makes communication with Earth impossible.

Telepathic twins Gill and Gail volunteer; one accompanying Chris Godfrey and the crew on the mission; the other remaining on Earth.

As they near their objective, Gail notices increasingly disruptive personality changes in the crew caused by the radiation, their only chance of survival is to land on the 'dark' side of the planet; however the near absolute zero conditions lead to massive heat-loss.

In the same year this book was published, radar observations of Mercury showed that it did not have a synchronous orbit and that the same face was not always in darkness.