Vintage Science Fiction Novels (two in one)

The image shows a classic Ace Double science fiction paperback from 1960, featuring The Martian Missile by David Grinnell. This edition (book number D-465) is a "tête-bêche" (head-to-tail) format where two novels are bound together upside-down relative to each other; the flip side of this book contains The Atlantic Abomination by John Brunner. Author: "David Grinnell" is a pseudonym for Donald A. Wollheim, a highly influential science fiction editor and the founder of DAW Books.