Mine Host, Mine Adversary — Lester Del Rey

It had been nearly fifteen years since the civilian rocket field had seen more than local traffic. Now, in spite of the bustle of emergency attendants and crews, the field buildings looked forlorn -- and deserted. Even some of the posters were of vintage brand. One, sheltered from the rain and sun, was still legible in its early crudity: TO BE BEATEN IS TO BE EATEN!