He tried to get his mind off that impulse by remembering that at eighteen thousand feet a good half of the air on Earth was underneath him, and by hoping that the other half would be as easy to rise above when the gyros were finally in place and starting out for space. The gyros, of course, were now on their way to be installed in the artificial satellite to be blasted up and set in an orbit around the Earth as the initial stage of that figurative stepladder by which men would make their first attempt to reach the stars. Until that Space Platform left the ground, the gyros were Joe's responsibility. The plane's co-pilot leaned back in his chair and stretched luxuriously. He loosened his safety belt and got up. He stepped carefully past the column between the right- and left-hand pilot seats. That column contained a fraction of the innumerable dials and controls the pilots of a modern multi-engine plane have to watch and handle. The co-pilot went to the coffeepot and flipped a switch. Joe fidgeted again on his improvised seat. Again he wished that he could be riding in back with the crates. But it would be silly to insist on perching somewhere in the freight compartment. There was a steady roaring in the cabin--the motors. One's ears got accustomed to it, and by now the noise sounded as if it were heard through cushions. Presently the coffeepot bubbled, unheard. The co-pilot lighted a cigarette. Then he drew a paper cup of coffee and handed it to the pilot. The pilot seemed negligently to contemplate some dozens of dials, all of which were duly duplicated on the right-hand, co-pilot's side. The co-pilot glanced at Joe. "Coffee?" "Thanks," said Joe. He took the paper cup. The co-pilot said: "Everything okay with you?" "I'm all right," said Joe. He realized that the co-pilot felt talkative. He explained: "Those crates I'm traveling with----. The family firm's been working on that machinery for months. It was finished with the final grinding done practically with feather dusters. I can't help worrying about it. There was four months' work in just lapping the shafts and balancing rotors. We made a telescope mounting once, for an observatory in South Africa, but compared to this gadget we worked on that one blindfolded!" "Pilot gyros, eh?" said the co-pilot. "That's what the waybill said. But if they were all right when they left the plant, they'll be all right when they are delivered." Joe said ruefully: "Still I'd feel better riding back there with them." "Sabotage bad at the plant?" asked the co-pilot. "Tough!" "Sabotage? No. Why should there be sabotage?" demanded Joe. The co-pilot said mildly: "Not quite everybody is anxious to see the Space Platform take off. Not everybody! What on earth do you think is the biggest problem out where they're building it?"