Then it was possible to feel the ship being pulled toward the Platform by the magnetic grapple. It was a landing-line. It was the means by which the ship would be docked in the giant lock which had been built to receive it.
As they drew near, they saw the joints of the plating of the Platform. They saw rivets. There was the huge, 30-foot doorway with its valves swung wide. Their searchlight beam glared into it. They saw the metal floor, and the bulging plastic sidewalls, restrained by nets. They saw the inner lock-door. It seemed that men should be visible to welcome them. There were none.
The airlock swallowed them. They touched against something solid. There were more clankings. They seemed to crunch against the metal floor—magnetic flooring-grapples. Then, in solid contact with the substance of the Platform, they heard the sounds of the great outer doors swinging shut. They were within the artificial satellite of Earth. It was bright in the lock, and Joe stared out the cabin ports at the quilted sides. There was a hissing of air, and he saw a swirling mist, and then the bulges of the sidewall sagged. The air pressure gauge was spinning up toward normal sea-level air pressure.
Joe threw the ready lever of the steering rockets to Off. "We're landed."
There was silence. Joe looked about him. The other three looked queer. It would have seemed natural for them to rejoice on arriving at their destination. But somehow they didn't feel that they had.
Joe said wrily, "It seems that we ought to weigh something, now we've got here. So we feel queer that we don't. Shoes, Mike?"
Mike peeled off the magnetic-soled slippers from their place on the cabin wall. He handed them out and opened the door. A biting chill came in it. Joe slipped on the shoe-soles with their elastic bands to hold them. He stepped out the door.
He didn't land. He floated until he reached the sidewall. Then he pulled himself down by the netting. Once he touched the floor, his shoes seemed to be sticky. The net and the plastic sidewalls were, of course, the method by which a really large airlock was made practical. When this ship was about to take off again, pumps would not labor for hours to pump the air out. The sidewalls would inflate and closely enclose the ship's hull, and so force the air in the lock back into the ship. Then the pumps would work on the air behind the inflated walls—with nets to help them draw the wall-stuff back to let the ship go free. The lock could be used with only fifteen minutes for pumping instead of four hours.
The door in the back of the lock clanked open. Joe tried to walk toward it. He discovered his astounding clumsiness. To walk in magnetic-soled shoes in weightlessness requires a knack. When Joe lifted one foot and tried to swing the other forward, his body tried to pivot. When he lifted his right foot, he had to turn his left slightly inward. His arms tried to float absurdly upward. When he was in motion and essayed to pause, his whole body tended to continue forward with a sedate toppling motion that brought him down flat on his face. He had to put one foot forward to check himself. He seemed to have no sense of balance. When he stood still—his stomach queasy because of weightlessness—he found himself tilting undignifiedly forward or back—or, with equal unpredictability, sidewise. He would have to learn an entirely new method of walking.
A man came in the lock, and Joe knew who it was. Sanford, the senior scientist of the Platform's crew. Joe had seen him often enough on the television screen in the Communications Room at the Shed. Now Sanford looked nerve-racked, but his eyes were bright and his expression sardonic.