Space Tug Part 2

"You can start on the pushpot motors, Haney," he said curtly.

Joe moved to his own, the pilot's seat. Haney pushed a b.u.t.ton. Through the fabric of the s.h.i.+p came the muted uproar of a pushpot engine starting. Haney pushed another b.u.t.ton. Another. Another. More jet engines bellowed. The tumult in the Shed would be past endurance, now.

Joe strapped himself into his seat. He made sure that the Chief at the steering-rocket manual controls was fastened properly, and Mike at the radio panel was firmly belted past the chance of injury.

Haney said with enormous calm, "All pushpot motors running, Joe."

"Steering rockets ready," the Chief reported.

"Radio operating," came from Mike. "Communications room all set."

Joe reached to the maneuver controls. He should have been sweating. His hands, perhaps, should have quivered with tension. But he was too much worried about too many things. n.o.body can strike an att.i.tude or go into a blue funk while they are worrying about things to be done. Joe heard the small gyro motors as their speed went up. A hum and a whine and then a shrill whistle which went up in pitch until it wasn't anything at all.

He frowned anxiously and said to Haney, "I'm taking over the pushpots."

Haney nodded. Joe took the over-all control. The roar of engines outside grew loud on the right-hand side, and died down. It grew thunderous to the left, and dwindled. The ones ahead pushed. Then the ones behind. Joe nodded and wet his lips. He said: "Here we go."

There was no more ceremony than that. The noise of the jet motors outside rose to a thunderous volume which came even through the little s.h.i.+p's insulated hull. Then it grew louder, and louder still, and Joe stirred the controls by ever so tiny a movement.

Suddenly the s.h.i.+p did not feel solid. It stirred a little. Joe held his breath and cracked the over-all control of the pushpots' speed a tiny trace further. The s.h.i.+p wobbled a little. Out the quartz-gla.s.s windows, the great door seemed to descend. In reality the cl.u.s.tered pushpots and the launching cage rose some thirty feet from the Shed floor and hovered there uncertainly. Joe s.h.i.+fted the lever that governed the vanes in the jet motor blasts. s.h.i.+p and cage and pushpots, all together, wavered toward the doorway. They pa.s.sed out of it, rocking a little and pitching a little and wallowing a little. As a flying device, the combination was a howling tumult and a horror. It was an aviation designer's nightmare.

It was a bad dream by any standard.

But it wasn't meant as a way to fly from one place to another on Earth.

It was the first booster stage of a three-stage rocket aimed at outer s.p.a.ce. It looked rather like--well--if a swarm of b.u.mblebees clung fiercely to a wire-gauze cage in which lay a silver minnow wrapped in match-sticks; and if the bees buzzed furiously and lifted it in a straining, clumsy, and altogether unreasonable manner; and if the appearance and the noise together were multiplied a good many thousands of times--why--it would present a great similarity to the take-off of the s.p.a.ces.h.i.+p under Joe's command. Nothing like it could be graceful or neatly controllable or even very speedy in the thick atmosphere near the ground. But higher, it would be another matter.

It _was_ another matter. Once clear of the Shed, and with flat, sere desert ahead to the very horizon, Joe threw on full power to the pushpot motors. The clumsy-seeming aggregation of grotesque objects began to climb. Ungainly it was, and clumsy it was, but it went upward at a rate a jet-fighter might have trouble matching. It wobbled, and it swung around and around, and it tipped crazily, the whole aggregation of jet motors and cage and burden of s.p.a.ces.h.i.+p as a unit. But it rose!

The ground dropped so swiftly that even the Shed seemed to shrivel like a p.r.i.c.ked balloon. The horizon retreated as if a carpet were hastily unrolled by magic. The barometric pressure needles turned.

"Communications says our rate-of-climb is 4,000 feet a minute and going up fast," Mike announced. "It's five.... We're at 17,000 feet ...

18,000. We should get some eastward velocity at 32,000 feet. Our height is now 21,000 feet...."

There was no change in the feel of things inside the s.h.i.+p, of course.

Sealed against the vacuum of s.p.a.ce, barometric pressure outside made no difference. Height had no effect on the air inside the s.h.i.+p.

At 25,000 feet the Chief said suddenly: "We're pointed due east, Joe.

Freeze it?"

"Right," said Joe. "Freeze it."

The Chief threw a lever. The gyros were running at full operating speed.

By engaging them, the Chief had all their stored-up kinetic energy available to resist any change of direction the pushpots might produce by minor variations in their thrusts. Haney brooded over the reports from the individual engines outside. He made minute adjustments to keep them balanced. Mike uttered curt comments into the communicator from time to time.

At 33,000 feet there was a momentary sensation as if the s.h.i.+p were tilted sharply. It wasn't. The instruments denied any change from level rise. The upward-soaring complex of flying things had simply risen into a jet-stream, one of those wildly rus.h.i.+ng wind-floods of the upper atmosphere.

"Eastern velocity four hundred," said Mike from the communicator. "Now four-twenty-five.... Four-forty."

There was a 300-mile-an-hour wind behind them. A tail-wind, west to east. The pushpots struggled now to get the maximum possible forward thrust before they rose out of that east-bound hurricane. They added a fierce push to eastward to their upward thrust. Mike's cracked voice reported 500 miles an hour. Presently it was 600.

At 40,000 feet they were moving eastward at 680 miles an hour. A jet-motor cannot be rated except indirectly, but there was over 200,000 horsepower at work to raise the s.p.a.cecraft 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 s.p.a.ce 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 s.p.a.ce 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 while the work of take-off could be divided, so that Joe would not be distracted. Now Joe had to control everything at once.

The roar of the pushpots outside the s.h.i.+p had long since lost the volume and timbre of normal atmosphere. Not much sound could be transmitted by the near-vacuum outside. But the jet motors did roar, and the sound which was not sound at such a height was transmitted by the metal cage as so much pure vibration. The walls and hull of the s.p.a.ces.h.i.+p picked up a crawling, quivering pulsation and turned it into sound. Standing waves set up and dissolved and moved erratically in the air of the cabin.

Joe's eardrums were strangely affected. Now one ear seemed muted by a temporary difference of air pressure where a standing wave lingered for a second or two. Then the other eardrum itched. There were creeping sensations as of things touching one and quickly moving away.

Joe swung a microphone into place before his mouth.

"All set," he said evenly. "Brief me."

The tinny voice said:

"_You are at 65,000 feet. Your curve of rate-of-climb is flattening out.

You are now rising at near-maximum speed, and not much more forward velocity can be antic.i.p.ated. You have an air-speed relative to surface of six-nine-two miles per hour. The rotational speed of Earth at this lat.i.tude is seven-seven-eight. You have, then, a total orbital speed of one-four-seven-oh miles per hour, or nearly twelve per cent of your needed final velocity. Since you will take off laterally and practically without air resistance, a margin of safety remains. You are authorized to blast._"

Joe said:

"Ten seconds. Nine ... eight ... seven ... six ... five ... four ...

three ... two ... one...."

He stabbed the master jato switch. And a monstrous jato rocket, built into each and every one of the pushpots outside, flared chemical fumes in a simultaneous, gigantic thrust. A small wire-wound jato for jet-a.s.sisted-take-off will weigh a hundred and forty pounds and deliver a thousand pounds of thrust for fourteen seconds. And that is for rockets using nonpoisonous compounds. The jatos of the pushpots used the beryllium-fluorine fuel that had lifted the Platform and that filled the take-off rockets of Joe's s.h.i.+p. These jatos gave the pushpots themselves an acceleration of ten gravities, but it had to be shared with the cage and the s.h.i.+p. Still....

Joe felt himself slammed back into his seat with irresistible, overwhelming force. The vibration from the jets had been bad. Now he didn't notice it. He didn't notice much of anything but the horrible sensations of six-gravity acceleration.

It was not exactly pain. It was a feeling as if a completely intolerable and unbearable pressure pushed at him. Not only on the outside, like a blow, but inside too, like nothing else imaginable. Not only his chest pressed upon his lungs, but his lungs strained toward his backbone. Not only the flesh of his thighs tugged to flatten itself against his acceleration-chair, but the blood in his legs tried to flow into and burst the blood-vessels in the back of his legs.

The six-gravity acceleration seemed to endure for centuries. Actually, it lasted for fourteen seconds. In that time it increased the speed of the little s.h.i.+p by rather more than half a mile per second, something over 1,800 miles per hour. Before, the s.h.i.+p 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 b.u.t.ton. 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 s.h.i.+p 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. n.o.body 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 t.i.tanic effort one could speak.

But there was the same feeling of stifling resistance to every movement that comes in nightmares.