L. Ron Hubbard 
To the Stars [PDF ebook] 

Space is deep, Man is small and Time is his relentless enemy….How far is too far? Alan Corday is about to find out. Corday is shanghaied aboard a futuristic starship bound on an interstellar journey. .on a trek at the speed of light, the world he leaves behind fast vanishing into the past through unexpected time travel. And nothing in the dark, forbidding reaches of space can prepare him for the astounding discovery he will make upon his return from the stars."Remarkably powerful novel." -John W. Campbell, Jr., Astounding Science Fiction