He heard the Chief grumbling to himself. But one tested space wagon was better than none.

The airlock doors opened. Huge round valves swung wide. Bright, remote, swarming stars filled the opening. Joe cracked the control of his forward liquid-fuel rockets. The lock filled instantly with swirling fumes. And instantly the tiny space wagon moved. It did not have to lift from the lock floor. Once the magnetic clamps were released it was free of the floor. But it did have mass. One brief push of the rockets sent it floating out of the lock. It was in space. It kept on.

Joe felt a peculiar twinge of panic. Nobody who is accustomed only to Earth can quite realize at the beginning the conditions of handling vehicles in space. But Joe cracked the braking rockets. He stopped. He hung seemingly motionless in space. The Platform was a good half-mile away.

He tried the gyros, and the space wagon went into swift spinning. He reversed them and straightened out—almost. The vastness of all creation seemed still to revolve slowly about him. The monstrous globe which was Earth moved sedately from above his head to under his feet and continued the slow revolution. The Platform rotated in a clockwise direction. He was drifting very slowly away.

"Chief," he said wrily, "you can't do worse than I'm doing, and we're rushed for time. You might come out. But listen! You don't run your rockets! On Earth you keep a motor going because when it stops, you do. But out here you have to use your motor to stop, but not to keep on going. Get it? When you do come out, don't burn your rockets more than half a second at a time."

The Chief's voice came booming:

"Right, Joe! Here I come!"

There was a billowing of frantically writhing fumes, which darted madly in every direction until they ceased to be. The Chief in his insect-like contraption came bolting out of the hole which was the airlock. He was a good half-mile away. The rocket fumes ceased. He kept on going. Joe heard him swear. The Chief felt the utterly helpless sensation of a man in a car when his brakes don't work. But a moment later the braking rockets did flare briefly, yet still too long. The Chief was not only stopped, but drifting backwards toward the Platform. He evidently tried to turn, and he spun as dizzily as Joe had done. But after a moment he stopped—almost. There were, then, two red-painted things in space, somewhat like giant water-spiders floating forlornly in emptiness. They seemed very remote from the great bright steel Platform and that gigantic ball which was Earth, turning very slowly and filling a good fourth of all that could be seen.

"Suppose you head toward me, Chief," said Joe absorbedly. "Aim to pass, and remember that what you have to estimate is not where I am, but where you have to put on the brakes to stop close by. That's where you use your braking-rockets."

The Chief tried it. He came to a stop a quarter-mile past Joe.