Gordon R Dickson 
Far Call [EPUB ebook] 

Along with a very few among the Earthbound billions of the 1990s, Jens Wylie dreamed of a future for Man among the stars. He seized the chance to become U.S. Undersecretary for the Development of Space and to help plan the first manned Mars voyage. But political compromise and corner-cutting built disaster into the expedition from the start. And when disaster struck, threatening the lives of the marsnauts and the whole destiny of the human race in space, only Jens saw what had to be done — and to do it, he had to risk his own life, face the loss of the woman he loves and defy the awesome power of the President of the United States.