acceleration seemed to endure for centuries. Actually, it lasted for fourteen seconds. In that time it increased the speed of the little ship by rather more than half a mile per second, something over 1,800 miles per hour. Before, the ship had possessed an orbital speed of a shade over 1,470 miles an hour. After the jato thrust, it was traveling nearly 3,400 miles per hour. It needed to travel something over 12,000 miles per hour to reach the artificial satellite of Earth.
The intolerable thrust ended abruptly. Joe gasped. But he could allow himself only a shake of the head to clear his brain. He jammed down the take-off rocket firing button. There was a monstrous noise and a mighty surging, and Haney panted, "Clear of cage. … "
And then they were pressed fiercely against their acceleration chairs again. The ship was no longer in its launching cage. It was no longer upheld by pushpots. It was free, with its take-off rockets flaming. It plunged on up and out. But the acceleration was less. Nobody can stand six gravities for long. Anybody can take three—for a while.
Joe's body resisted movement with a weight of four hundred and fifty pounds, instead of a third as much for normal. His heart had to pump against three times the normal resistance of gravity. His chest felt as if it had a leaden weight on it. His tongue tried to crowd the back of his mouth and strangle him. The sensation was that of a nightmare of impossible duration. It was possible to move and possible to see. One could breathe, with difficulty, and with titanic effort one could speak. But there was the same feeling of stifling resistance to every movement that comes in nightmares.
But Joe managed to keep his eyes focused. The dials of the instruments said that everything was right. The tinny voice behind his head, its timbre changed by the weighting of its diaphragm, said: "All readings check within accuracy of instruments. Good work!"
Joe moved his eyes to a quartz window. The sky was black. But there were stars. Bright stars against a black background. At the same instant he saw the bright white disks of sunshine that came in the cabin portholes. Stars and sunshine together. And the sunshine was the sunshine of space. Even with the polarizers cutting off some of the glare it was unbearably bright and hot beyond conception. He smelled overheated paint, where the sunlight smote on a metal bulkhead. Stars and super-hot sunshine together. …
It was necessary to pant for breath, and his heart pounded horribly and his eyes tried to go out of focus, but Joe Kenmore strained in his acceleration-chair and managed to laugh a little.
"We did it!" he panted. "In case you didn't notice, we're out of—the atmosphere and—out in space! We're—headed to join the Space Platform!"
2
The pressure of three gravities continued. Joe's chest muscles ached with the exertion of breathing over so long a period. Six gravities for fourteen seconds had been a ghastly ordeal. Three gravities for minutes built up to something nearly as bad. Joe's heart began to feel fatigue, and a man's heart normally simply doesn't ever feel tired. It became more and more difficult to see clearly.
But he had work to do. Important work. The take-off rockets were solid-fuel jobs, like those which launched the Platform. They were wire-wound steel tubes lined with a very special refractory, with unstable beryllium and fluorine compounds in them. The solid fuel burned at so many inches per second. The refractory crumbled away and was hurled astern at a corresponding rate—save for one small point. The refractory was not all exactly alike. Some parts of it crumbled away faster, leaving a pattern of baffles which acted like a maxim silencer on a rifle, or like an automobile muffler. The baffles set up eddies in the gas stream and produced exactly the effect of a rocket motor's throat. But the baffles themselves crumbled and were flung astern, so that the solid-fuel rockets had always the efficiency of gas-throated rocket motors; and yet every bit of refractory was reaction-mass to be hurled astern, and even the steel tubes melted and were hurled away with a gain in acceleration to the ship. Every fraction of every ounce of rocket mass was used for drive. No tanks or pumps or burners rode deadhead after they ceased to be useful.
But solid-fuel rockets simply can't be made to burn with absolute evenness as a team. Minute differences in burning-rates do tend to cancel out. But now and again they reinforce each other and if uncorrected will throw a ship off course. Gyros can't handle such effects. So Joe had to watch his instruments and listen to the tinny voice behind him and steer the ship against accidental wobblings as the Earth fell away behind him.
He battled against the fatigue of continuing to live, and struggled with gyros and steering jets to keep the ship on its hair-line course. He panted heavily. The beating of his heart became such a heavy pounding that it seemed that his whole body shook with it. He had to do infinitely fine precision steering with hands that weighed pounds and arms that weighed scores of pounds and a body that had an effective weight of almost a quarter of a ton.
And this went on and went on and on for what seemed several centuries.
Then the voice in the speaker said thickly: "Everything is in the clear. In ten seconds you can release your rockets. Shall I count?"
Joe panted, "Count!"
The mechanical voice said, "Seven … six … five … four … three … two … one … cut!"
Joe pressed the release. The small, unburnt stubs of the take-off rockets went hurtling off toward emptiness. They consumed themselves as they went, and they attained an acceleration of fifty gravities once they were relieved of all load but their own substance. They had to be released lest one burn longer than another. It was also the only way to stop acceleration by solid-fuel rockets. They couldn't be extinguished. They had to be released.
From intolerably burdensome heaviness, there was abruptly no weight at all in the ship. Joe's laboring heart beat twice with the violence the weight had called for, though weight had ended. It seemed to him that his skull would crack open during those two heart-beats. Then he lay limply, resting.
There was a completely incredible stillness, for a time. The four of them panted. Haney was better off than Joe, but the Chief was harder hit. Mike's small body had taken the strain best of all, and he would use the fact later in shrill argument that midgets were designed by nature to be the explorers of space for their bulkier and less spaceworthy kindred.
The ending of the steady, punishing drag was infinitely good, but the new sensation was hardly pleasant. They had no weight. It felt as if they and the ship about them were falling together down an abyss which must have a bottom. Actually, they were falling up. But they felt a physical, crawling apprehension—a cringing from an imaginary imminent impact.
They had expected the sensation, but it was not the better for being understood. Joe flexed and unflexed his fingers slowly. He stirred and swallowed hastily. But the feeling persisted. He unstrapped himself from his seat. He stood up—and floated to the ceiling of the cabin. But there was of course no ceiling. Every way was up and every way was down. His stomach cramped itself in a hard knot, in the instinctive tensity of somebody in free fall.
He fended himself from the ceiling and caught at a hand-line placed there for just this necessity to grip something. In his absorption, he did not notice which way his heels went. He suddenly noticed that his companions, with regard to him, were upside down and staring at him with wooden, dazed expressions on their faces.
He tried to laugh, and gulped instead. He pulled over to the quartz-glass ports. He did not put his hand into the sunlight, but shifted the glare shutters over those ports which admitted direct sunshine. Some ports remained
