“That’s Hotel de Gink service,” said Talley. “No wasted motion, no sloppy civilities. He was about to eat that himself, he gave it to you, and now he’ll cook himself a double portion of everything. What are you doing here, anyhow?”

Joe shrugged. It occurred to him that it would neither be wise nor creditable to say that he’d been sent here to split up a target at which saboteurs might shoot.

“I guess I’m attached for rations,” he observed. “There’ll be orders along about me presently, I suppose. Then I’ll know what it’s all about.”

He fell to on his breakfast. The thunderous noises of the pushpots taking off made the mess hall quiver. Joe said between mouthfuls: “Funny way for anything to take off, riding on—it looked like a truck.”

“It is a truck,” said Talley. “A high-speed truck. Fifty of them specially made to serve as undercarriages so pushpot pilots can practice. The pushpots are really only expected to work once, you know.”

Joe nodded.

“They aren’t to take off,” Talley explained. “Not in theory. They hang on to the Platform and heave. They go up with it, pushing. When they get it as high as they can, they’ll shoot their jatos, let go, and come bumbling back home. So they have to practice getting back home and landing. For practicing it doesn’t matter how they get aloft. When they get down, a big straddle truck on caterpillar treads picks them up—they land in the doggonedest places, sometimes!—and brings ’em back. Then a crane heaves them up on a high-speed truck and they do it all over again.”

Joe considered while he ate. It made sense. The function of the pushpots was to serve as the first booster stage of a multiple-stage rocket. Together, they would lift the Platform off the ground and get it as high as their jet motors would take it traveling east at the topmost speed they could manage. Then they’d fire their jatos simultaneously, and in doing that they’d be acting as the second booster stage of a multiple-stage rocket. Then their work would be done, and their only remaining purpose would be to get their pilots back to the ground alive, while the Platform on its own third stage shot out to space.

“So,” said Talley, “since their pilots need to practice landings, the trucks get them off the ground. They go up to fifty thousand feet, just to give their oxygen tanks a chance to conk out on them; then they barge around up there a while. The advanced trainees shoot off a jato at top speed. It’s gauged to build them up to the speed they’ll give the Platform. And then if they come out of that and get back down to ground safely, they uncross their fingers. A merry life those guys lead! When a man’s made ten complete flights he retires. One flight a week thereafter to keep in practice only, until the big day for the Platform’s take-off. Those guys sweat!”