Collision Course

Collision Course is a science fiction novel by American author Robert Silverberg, first published in hardcover in 1961 by Avalon Books and reprinted in paperback as an Ace Double later that year. Ace reissued it as a stand-alone volume in 1977 and 1982; a Tor paperback appeared in 1988. An Italian translation was also published in 1961, and a German translation later appeared. Silverberg planned the novel as a serial for Astounding Science Fiction, but John W. Campbell rejected the work and Silverberg eventually sold a shorter version to Amazing Stories, where it appeared in 1959.