horsepower at work to raise the spacecraft and build up the highest
possible forward speed. It couldn't be kept up, of course. The pushpots
couldn't carry enough fuel.

But they reached 55,000 feet, which is where space begins for humankind.
A man exposed to emptiness at that height will die just as quickly as
anywhere between the stars. But it wasn't quite empty space for the
pushpots. There was still a very, very little air. The pushpots could
still thrust upward. Feebly, now, but they still thrust.

Mike said: "Communications says get set to fire jatos, Joe."

"Right!" he replied. "Set yourselves."

Mike flung a switch, and a voice began to chatter behind Joe's head. It
was the voice from the communications-room atop the Shed, now far below
and far behind. Mike settled himself in the tiny acceleration-chair
built for him. The Chief squirmed to comfort in his seat. Haney took his
hands from the equalizing adjustments he had to make so that Joe's use
of the controls would be exact, regardless of moment-to-moment
differences in the thrust of the various jets.

"We've got a yaw right," said the Chief sharply. "Hold it, Joe!"

Joe waited for small quivering needles to return to their proper
registrations.

"Back and steady," said the Chief a moment later. "Okay!"

The tinny voice behind Joe now spoke precisely. Mike had listened to it