As he was strapped down, the tester said to him, “This is called the ‘Centrifuge,’ son, and it simulates the blast-off from Earth in a rocket ship. You appear to be a little young to be taking it, so if you’ve had enough just yank that lever in front of you and we’ll stop the machine.” “I—I will,” Gib replied, getting scared already. He got more scared as all sorts of instruments were strapped to him. The tester explained that these were to record his reactions. As the door was closed on him. Gib had a trapped feeling. Then he composed himself and waited for the worst, telling himself that a spaceman must be brave. Presently he felt the cabin begin to move, slowly at first. This much was fun, Gib thought, just like the carnival ride. As the cabin picked up speed, it was even more thrilling. But then as the speed increased still more, Gib began to lose his enjoyment. Faster and faster he went, and Gib was crushed deeply into the chair cushion. He felt his cheeks draw back from his teeth, the corners of his eyes making him squint. There was heavy pressure on his chest, as if an elephant were standing on him. His breath hung in his throat and he saw strange colors and darting forms before his eyes. He stood the agonizing effect as long as he could, and then his frightfully heavy hand crept unsteadily toward the lever in front of him and jerked it. The cabin began losing speed and finally stopped. Gib saw a blurred image open the door and offer his hand. As he stumbled out, his head feeling big as a watermelon, Gib vaguely remembered hearing the tester say: “You needn’t feel badly about this, son. You almost lasted it out. Come back in another year or two and then I think you’ll be able to pass.” Gib still wasn’t quite himself as he met his father in the waiting room. He was quivering all over, and his dad wouldn’t quite come into focus. “I flunked the test, Father,” Gib told him. “It sounds to me as if you’re glad you did,” Mr. Bromfield replied, with a chuckle. “I was afraid it might be too rough for you, son, but I knew there was no other way to show you that space travel isn’t as easy as the comic books make out.” “I’ll try again next year,” Gib said, “or the year after that, anyway. That’s what the tester told me.” “I’m sure you’ll be ready then,” Mr. Bromfield replied. “Now, what do you say we go home? Captain Rocket is almost due on TV.” _THE SPACE MAIL RUN_ The way he felt now, Jerry Welsh was almost sorry he had left Earth. The Moonship landing seemed to be crushing the very life out of him, although he lay flat on a couch to ease the strain. Jerry turned his head toward his father, who was strapped down like himself, and suffering too. The craft was under its own control, for no human could withstand the rocket’s present speed and still be able to steer in for a landing.