Space Tug

8

All the sensations were familiar, the small fleet of improbable objects rose and rose. Of all flying objects ever imagined by man, the launching cages supported by pushpots were most irrational.

The squadron, though, went bumbling upward. In the manned ship, Joe was more tense than on his other take-off—if such a thing was possible. His work was harder this trip. Before, he'd had Mike at communications and the Chief at the steering rockets while Haney kept the pushpots balanced for thrust. Now Joe flew the manned ship alone. Headphones and a mike gave him communications with the Shed direct, and the pushpots were balanced in groups, which cost efficiency but helped on control. He would have, moreover, to handle his own steering rockets during acceleration and when he could—and dared—he should supervise the others. Because each of the other three had two drone-ships to guide. True, they had only to keep their drones in formation, but Joe had to navigate for all. The four of them had been assigned this flight because of its importance. They happened to be the only crew alive who had ever flown a space ship designed for maneuvering, and their experience consisted of a single trip.

The jet stream was higher this time than on that other journey now two months past. They blundered into it at 36,000 feet. Joe's headphones buzzed tinnily. Radar from the ground told him his rate-of-rise, his ground speed, his orbital speed, and added comments on the handling of the drones.

The last was not a precision job. On the way up Joe protested, "Somebody's ship—Number Four—is lagging! Snap it up!"

Mike said crisply, "Got it, Joe. Coming up!"

"The Shed says three separate ships are getting out of formation. And we need due east pointing. Check it."

The Chief muttered, "Something whacky here ... come round, you! Okay, Joe."

Joe had no time for reflection. He was in charge of the clumsiest operation ever designed for an exact result. The squadron went wallowing toward the sky. The noise was horrible. A tinny voice in his headphones:

"You are at 65,000 feet. Your rate-of-climb curve is flattening. You should fire your jatos when practical. You have some leeway in rocket power."

Joe spoke into the extraordinary maze of noise waves and pressure systems in the air of the cabin.

"We should blast. I'm throwing in the series circuit for jatos. Try to line up. We want the drones above us and with a spread, remember! Go to it!"

He watched his direction indicator and the small graphic indicators telling of the drones. The sky outside the ports was dark purple. The launching cage responded sluggishly. Its open end came around toward the east. It wobbled and wavered. It touched the due-east point. Joe stabbed the firing-button.

Nothing happened. He hadn't expected it. The seven ships had to keep in formation. They had to start off on one course—with a slight spread as a safety measure—and at one time. So the firing-circuits were keyed to relays in series. Only when all seven firing-keys were down at the same time would any of the jatos fire. Then all would blast together.

The pilots in the cockpit-bubbles of the pushpots had an extraordinary view of the scene. At something over twelve miles height, seven aggregations of clumsy black things clung to frameworks of steel, pushing valorously. Far below there were clouds and there was Earth. There was a horizon, which wavered and tilted. The pushpots struggled with seeming lack of purpose. One of the seven seemed to drop below the others. They pointed vaguely this way and that—all of them. But gradually they seemed to arrive at an uncertain unanimity.

Joe pushed the firing-button again as his own ship touched the due-east mark. Again nothing happened. Out of the corner of his eye he saw Haney pressing down both buttons. The Chief's finger lifted. Mike pushed down one button and held off the other.

Roarings and howlings of pushpots. Wobblings and heart-breaking clumsinesses of the drone-ships. They hung in the sky while the pushpots used up their fuel.

"We've got to make it soon," said Joe grimly. "We've got forty seconds. Or we'll have to go down and try again."

There was a clock dial with a red sweep-hand which moved steadily and ominously toward a deadline time for firing. Up to that deadline, the pushpots could let the ships back down to Earth without crashing them. After it, they'd run out of fuel before a landing could be made.

The deadline came closer and closer. Joe snapped:

"Take a degree leeway. We've got ten seconds."

He had the manned ship nearly steady. He held down the firing-button, holding aim by infinitesimal movements of the controls. Haney pushed both hands down, raised one, pushed again. The Chief had one finger down. Mike had both firing buttons depressed.... The Chief pushed down his second button, quietly.

There was a monstrous impact. Every jato in every pushpot about every launching cage fired at once. Joe felt himself flung back into his acceleration chair. Six gravities. He began the horrible fight to stay alive, while the blood tried to drain from the conscious forepart of his brain, and while every button of his garments pressed noticeably against him, and objects in his pockets pushed. The sides of his mouth dragged back, and his cheeks sagged, and his tongue strove to sink back into his throat and strangle him.

It was very bad. It seemed to last for centuries.

Then the jatos burned out. There was that ghastly feeling of lunging forward to weightlessness. One instant, Joe's body weighed half a ton. The next instant, it weighed less than a dust grain. His head throbbed twice as if his skull were about to split open and let his brains run out. But these things he had experienced before.

There were pantings in the cabin about him. The ship fell. It happened to be going up, but the sensation and the fact was free fall. Joe had been through this before, too. He gasped for breath and croaked, "Drones?"

"Right," said Haney.

Mike panted anxiously, "Four's off course. I'll fix it."

The Chief grunted guttural Mohawk. His hands stirred on the panel for remote control of the drones he had to handle.

"Crazy!" he growled. "Got it now, Joe. Fire when ready."

"Okay, Mike?"

A half-second pause.

"Okay!"

Joe pressed the firing-button for the take-off rockets. And he was slammed back into his acceleration chair again. But this was three gravities only. Pressed heavily against the acceleration cushions, he could perform the navigation for the fleet. He did. The mother-ship had to steer a true course, regardless of the vagaries of its rockets. The drones had simply to be kept in formation with it. The second task was simpler. But Joe was relieved, this time, of the need to report back instrument-readings. A telemetering device took care of that.

The take-off rockets blasted and blasted and blasted. The mere matter of staying alive grew very tedious. The ordeal seemed to last for centuries. Actually it could be measured only in minutes. But it seemed millennia before the headphones said, staccato fashion: "You are on course and will reach speed in fourteen seconds. I will count for you."

"Relays for rocket release," panted Joe. "Throw 'em over!"

Three hands moved to obey. Joe could release the drive rockets on all seven ships at will.

The voice counted:

"Ten ... nine ... eight ... seven ... six ... five ... four ... three ... two ... one ... cut!"

Joe pressed the master-key. The remnants of the solid-fuel take-off rockets let go. They flashed off into nothingness at unbelievable speed, consuming themselves as they went.

There was again no weight.

This time there was no resting. No eager gazing out the cabin ports. Now they weren't curious. They'd had over a month in space, and something like sixteen days back on Earth, and now they were back in space again.

Mike and Haney and the Chief worked doggedly at their control boards. The radar bowls outside the cabin shifted and moved and quivered. The six drone ships showed on the screens. But they also had telemetering apparatus. They faithfully reported their condition and the direction in which their bows pointed. The radars plotted their position with relation to each other and the mother-ship.

Presently Joe cast a glance out of a port and saw that the dark line of sunset was almost below. The take-off had been timed to get the ships into Earth's shadow above the area from which war rockets were most likely to rise. It wouldn't prevent bombing, of course. But there was a gadget....

Joe spoke into the microphone: "Reporting everything all right so far. But you know it."

The voice from solid ground said, "Report acknowledged."

The ships went on and on and on. The Chief muttered to himself and made very minute adjustments of the movement of one of his drones. Mike fussed with his. Haney regarded the controls of his drones with a profound calm.

Nothing happened, except that they seemed to be falling into a bottomless pit and their stomach-muscles knotted and cramped in purely reflex response to the sensation. Even that grew tedious.

The headphones said, "You will enter Earth's shadow in three minutes. Prepare for combat."

Joe said drily, "We're to prepare for combat."

The Chief growled. "I'd like to do just that!"

The phrasing, of course, was intentional—in case enemy ears were listening. Actually, the small fleet was to use a variant on the tin can shield which protected the Platform. It would be most effective if visual observation was impossible. The fleet was seven ships in very ragged formation. Most improbably, after the long three-gravity acceleration, they were still within a fifty-mile globe of space. Number Four loitered behind, but was being brought up by judicious bursts of steering-rocket fire. Number Two was some distance ahead. The others were simply scattered. They went floating on like a group of meteors. Out the ports, two of them were visible. The others might be picked out by the naked eye—but it wasn't likely.

Drone Two, far ahead and clearly visible, turned from a shining steel speck to a reddish pin-point of light. The red color deepened. It winked out. The sunlight in the ports of the mother-ship turned red. Then it blacked out.

"Shoot the ghosts," said Joe.

The three drone-handlers pushed their buttons. Nothing happened that anybody could see. Actually, though, a small gadget outside the hull began to cough rhythmically. Similar devices on the drones coughed, too. They were small, multiple-barreled guns. Rifle shells fired two-pound missiles at random targets in emptiness. They wouldn't damage anything they hit. They'd go varying distances, explode and shoot small lead shot ahead to check their missile-velocity, and then emit dense masses of aluminum foil. There was no air resistance. The shredded foil would continue to move through emptiness at the same rate as the convoy-fleet. The seven ships had fired a total of eighty-four such objects away into the blackness of Earth's shadow. There were, then, seven ships and eighty-four masses of aluminum foil moving through emptiness. They could not be seen by telescopes.

And radars could not tell ships from masses of aluminum foil.

If enemy radars came probing upward, they reported ninety-one space ships in ragged but coherent formation, soaring through emptiness toward the Platform. And a fleet like that was too strong to attack.

The radar operators had been prepared to forward details of the speed and course of a single ship to waiting rocket-launching submarines half-way across the Pacific. But they reported to Very High Authority instead.

He received the report of an armada—an incredible fleet—in space. He didn't believe it. But he didn't dare disbelieve it.

So the fleet swam peacefully through the darkness that was Earth's shadow, and no attempt at attack was made. They came out into sunlight to look down at the western shore of America itself. With seven ships to get on an exact course, at an exact speed, at an exact moment, time was needed. So the fleet made almost a complete circuit of the Earth before reaching the height of the Platform's orbit.

They joined it. A single man in a space suit, anchored to its outer plates, directed a plastic hose which stretched out impossibly far and clamped to one drone with a magnetic grapple. He maneuvered it to the hull and made it fast. He captured a second, which was worked delicately within reach by coy puffs of steering-rocket vapor.

One by one, the drones were made fast. Then the manned ship went in the lock and the great outer door closed, and the plastic-fabric walls collapsed behind their nets, and air came in.

Lieutenant Commander Brown was the one to come into the lock to greet them. He shook hands all around—and it again seemed strange to all the four from Earth to find themselves with their feet more or less firmly planted on a solid floor, but their bodies wavering erratically to right and left and before and back, because there was no up or down.

"Just had reports from Earth," Brown told Joe comfortably. "The news of your take-off was released to avoid panic in Europe. But everybody who doesn't like us is yelling blue murder. Somebody—you may guess who—is announcing that a fleet of ninety-one war rockets took off from the United States and now hangs poised in space while the decadent American war-mongers prepare an ultimatum to all the world. Everybody's frightened."

"If they'll only stay scared until we get unloaded," said Joe in some satisfaction, "the government back home can tell them how many we were and what we came up for. But we'll probably make out all right, anyhow."

"My crew will unload," said Brown, in conscious thoughtfulness. "You must have gotten pretty well exhausted by that acceleration."

Joe shook his head. "I think we can handle the freight faster. We found out a few things by going back to Earth."

A section of plating at the top of the lock—at least it had been the top when the Platform was built on Earth—opened up as on the first journey here. A face grinned down. But from this point on, the procedure was changed. Haney and Joe went into the cargo-section of the rocketship and heaved its contents smoothly through weightlessness to the storage chamber above. The Chief and Mike stowed it there. The speed and precision of their work was out of all reason. Brown stared incredulously.

The fact was simply that on their first trip to the Platform, Joe and his crew didn't know how to use their strength where there was no weight. By the time they'd learned, their muscles had lost all tone. Now they were fresh from Earth, with Earth-strength muscles—and they knew how to use them.

"When we got back," Joe told Brown, "we were practically invalids. No exercise up here. This time we've brought some harness to wear. We've some for you, too."

They moved out of the airlock, and the ship was maneuvered to a mooring outside, and a drone took its place. Brown's eyes blinked at the unloading of the drone. But he said, "Navy style work, that!"

"Out here," said Joe, "you take no more exercise than an invalid on Earth—in fact, not as much. By now the original crew would have trouble standing up on a trip back to Earth. You'd feel pretty heavy, yourself."

Brown frowned.

"Hm. I—ah—I shall ask for instructions on the matter."

He stood erect. He didn't waver on his feet as the others did. But he wore the same magnetic-soled shoes. Joe knew, with private amusement, that Brown must have worked hard to get a dignified stance in weightlessness.

"Mr. Kenmore," said Brown suddenly. "Have you been assigned a definite rank as yet?"

"Not that I know of," said Joe without interest. "I skipper the ship I just brought up. But——"

"Your ship has no rating!" protested Brown irritably. "The skipper of a Navy ship may be anything from a lieutenant junior grade to a captain, depending on the size and rating of the ship. In certain circumstances even a noncommissioned officer. Are you an enlisted man?"

"Again, not that I know of," Joe told him. "Nor my crew, either."

Brown looked at once annoyed and distressed.

"It isn't regular!" he objected. "It isn't shipshape! I should know whether you are under my command or not! For discipline! For organization! It should be cleared up! I shall put through an urgent inquiry."

Joe looked at him incredulously. Lieutenant Commander Brown was a perfectly amiable man, but he had to have things in a certain pattern for him to recognize that they were in a pattern at all. He was more excited over the fact that he didn't know whether he ranked Joe, than over the much more important matter of physical deterioration in the absence of gravity. Yet he surely understood their relative importance. The fact was, of course, that he could confidently expect exact instructions about the last, while he had to settle matters of discipline and routine for himself.

"I shall ask for clarification of your status," he said worriedly. "It shouldn't have been left unclear. I'd better attend to it at once."

He looked at Joe as if expecting a salute. He didn't get it. He clanked away, his magnetic shoe-soles beating out a singularly martial rhythm. He must have practised that walk, in private.

Joe got out of the airlock as another of the space barges was warped in. Brent, the crew's psychologist, joined him when he went to unload. Brent nodded in a friendly fashion to Joe.

"Quite a change, eh?" he said drily. "Sanford turned out to be a crackpot with his notions of grandeur. I'm not sure that Brown's notions of discipline aren't worse."

Joe said, "I've something rather important to pass on," and told about the newly discovered physical effects of a long stay where there was no gravity. The doctors now predicted that anybody who spent six months without weight would suffer a deterioration of muscle tone which could make a return to Earth impossible without a long preliminary process of retraining. One's heart would adjust to the absence of any need to pump blood against gravity.

"Which," said Joe, "means that you're going to have to be relieved before too long. But we brought up some gravity-simulator harness that may help."

Brent said desolately: "And I was so pleased! We all had trouble with insomnia, at first, but lately we've all been sleeping well! Now I see why! Normally one sleeps because he's tired. We had trouble sleeping until our muscles got so weak we tired anyhow!"

Another drone came in and was unloaded. And another and another. But the last of them wasn't only unloaded. Haney took over the Platform's control board and—grinning to himself—sent faint, especially-tuned short wave impulses to the steering-rockets of the drone. The liquid-fuel rockets were designed to steer a loaded ship. With the airlock door open, the silvery ship leaped out of the dock like a frightened horse. The liquid-fuel rocket had a nearly empty hull to accelerate. It responded skittishly.

Joe watched out a port as it went hurtling away. The vast Earth rolled beneath it. It sped on and vanished. Its fumes ceased to be visible. Joe told Brent:

"Another nice job, that! We sent it backward, slowing it a little. It'll have a new orbit, independent of ours and below it. But come sixty hours it will be directly underneath. We'll haul it up and refuel it. And our friends the enemy will hate it. It's a radio repeater. It'll pick up short-wave stuff beamed to it, and repeat it down to Earth. And they can try to jam that!"

It was a mildly malicious trick to play. Behind the Iron Curtain, broadcasts from the free world couldn't be heard because of stations built to emit pure noise and drown them out. But the jamming stations were on the enemy nations' borders. If radio programs came down from overhead, jamming would be ineffective at least in the center of the nations. Populations would hear the truth, even though their governments objected.

But that was a minor matter, after all. With space ship hulls coming into being by dozens, and with one convoy of hundreds of tons of equipment gotten aloft, the whole picture of supply for the Platform had changed.

Part of the new picture was two devices that Haney and the Chief were assembling. They were mostly metal backbone and a series of tanks, with rocket motors mounted on ball and socket joints. They looked like huge red insects, but they were officially rocket recovery vehicles, and Joe's crew referred to them as space wagons. They had no cabin, but something like a saddle. Before it there was a control-board complete with radar-screens. And there were racks to which solid-fuel rockets of divers sizes could be attached. They were literally short-range tow craft for travel in space. They had the stripped, barren look of farm machinery. So the name "space wagon" fitted. There were two of them.

"We're putting the pair together," the Chief told Joe. "Looks kinda peculiar."

"It's only for temporary use," said Joe. "There's a bigger and better one being built with a regular cabin and hull. But some experience with these two will be useful in running a regular space tug."

The Chief said with a trace too much of casualness: "I'm kind of looking forward to testing this."

"No," said Joe doggedly. "I'm responsible. I take the first chance. But we should all be able to handle them. When this is assembled you can stand by with the second one. If the first one works all right, we'll try the second."

The Chief grimaced, but he went back to the assembly of the spidery device.

Joe got out the gravity-simulator harnesses. He showed Brent how they worked. Brown hadn't official instructions to order their use, but Joe put one on himself, set for full Earth-gravity simulation. He couldn't imitate actual gravity, of course. Only the effect of gravity on one's muscles. There were springs and elastic webbing pulling one's shoulders and feet together, so that it was as much effort to stand extended—with one's legs straight out—as to stand upright on Earth. Joe felt better with a pull on his body.

Brent was upset when he found that to him more than a tenth of normal gravity was unbearable. But he kept it on at that. If he increased the pull a very little every day, he might be able to return to Earth, in time. Now it would be a very dangerous business indeed. He went off to put the other members of the crew in the same sort of harness.

After ten hours, a second drone broadcaster went off into space. By that time the articulated red frameworks were assembled. They looked more than ever like farm machinery, save that their bulging tanks made them look insectile, too. They were actually something between small tow-boats and crash-wagons. A man in a space suit could climb into the saddle of one of these creations, plug in the air-line of his suit to the crash-wagon's tanks, and travel in space by means of the space wagon's rockets. These weird vehicles had remarkably powerful magnetic grapples. They were equipped with steering rockets as powerful as those of a ship. They had banks of solid-fuel rockets of divers power and length of burning. And they even mounted rocket missiles, small guided rockets which could be used to destroy what could not be recovered. They were intended to handle unmanned rocket shipments of supplies to the Platform. There were reasons why the trick should be economical, if it should happen to work at all.

When they were ready for testing, they seemed very small in the great space lock. Joe and the Chief very carefully checked an extremely long list of things that had to work right or nothing would work at all. That part of the job wasn't thrilling, but Joe no longer looked for thrills. He painstakingly did the things that produced results. If a sense of adventure seemed to disappear, the sensations of achievement more than made up for it.

They got into space suits. They were in an odd position on the Platform. Lieutenant Commander Brown had avoided Joe as much as possible since his arrival. So far he'd carefully avoided giving him direct orders, because Joe was not certainly and officially his subordinate. Lacking exact information, the only thing a conscientious rank-conscious naval officer could do was exercise the maximum of tact and insistently ask authority for a ruling on Joe's place in the hierarchy of rank.

Joe flung a leg over his eccentric, red-painted mount. He clipped his safety-belt, plugged in his suit air-supply to the space wagon's tanks, and spoke into his helmet transmitter.

"Okay to open the lock. Chief, you keep watch. If I make out all right, you can join me. If I get in serious trouble, come after me in the ship we rode up. But only if it's practical! Not otherwise!"

The Chief said something in Mohawk. He sounded indignant.

The plastic walls of the lock swelled inward, burying and overwhelming them. Pumps pounded briefly, removing what air was left. Then the walls drew back, straining against their netting, and Joe waited for the door to open to empty space.

Instead, there came a sharp voice in his helmet-phones. It was Brown. "Radar says there's a rocket on the way up! It's over at what is the edge of the world from here. Three gravities only. Better not go out!"

Joe hesitated. Brown still issued no order. But defense against a single rocket would be a matter of guided missiles—Brown's business—if the tin can screen didn't handle it. Joe would have no part in it. He wouldn't be needed. He couldn't help. And there'd be all the elaborate business of checking to go through again. He said uncomfortably:

"It'll be a long time before it gets here—and three gravities is low! Maybe it's a defective job. There have been misfires and so on. It won't take long to try this wagon, anyhow. They're anxious to send up a robot ship from the Shed and these have to be tested first. Give me ten minutes."

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.

"I'm heavy-handed," said his voice disgustedly.

"I'll try to join you," said Joe.

He did try. He stopped a little short. The two weird objects drifted almost together. The Chief was upside down with regard to Joe. Presently he was sidewise on.

"This takes thinking," said Joe ruefully.

A voice in his headphones, from the Platform, said:

"That rocket from Earth is still accelerating. Still at three gravities. It looks like it isn't defective. It might be carrying a man. Hadn't you better come in?"

The Chief growled: "We won't be any safer there! I want to get the hang of this." Then his voice changed sharply. "Joe! D'you get that?"

Joe heard his own voice, very cold.

"I didn't. I do now. Brown, I'd suggest a guided missile at that rocket coming up. If there's a man in it, he's coming up to take over guided missiles that'll overtake him, and try to smash the Platform by direct control, since proximity fuses don't work. I'd smash him as far away as possible."

Brown's voice came very curt and worried. "Right."

There was an eruption of rocket fumes from the side of the Platform. Something went foaming away toward Earth. It dwindled with incredible rapidity. Then Joe said:

"Chief, I think we'd better go down and meet that rocket. We'll learn to handle these wagons on the way. I think we're going to have a fight on our hands. Whoever's in that rocket isn't coming up just to shake hands with us."

He steadied the small red vehicle and pointed it for Earth. He added:

"I'm firing a six-two solid-fuel job, Chief. Counting three. Three—two—one."

His mount vanished in rocket fumes. But after six seconds at two gravities acceleration the rocket burned out. The Chief had fired a matching rocket. They were miles apart, but speeding Earthward on very nearly identical courses.

The Platform grew smaller. That was their only proof of motion.

A very, very long time passed. The Chief fired his steering rockets to bring him closer to Joe. It did not work. He had to aim for Joe and fire a blast to move noticeably nearer. Presently he would have to blast again to keep from passing.

Joe made calculations in his head. He worried. He and the Chief were speeding Earthward—away from the Platform—at more than four miles a minute, but it was not enough. The manned rocket was accelerating at a great deal more than that rate. And if the Platform's enemies down on Earth had sent a manned rocket up to destroy the Platform, the man in it would have ways of defending himself. He would expect guided missiles—but he probably wouldn't expect to be attacked by space wagons.

Joe said suddenly:

"Chief! I'm going to burn a twelve-two. We've got to match velocities coming back. Join me? Three—two—one."

He fired a twelve-two. Twelve seconds burning, two gravities acceleration. It built up his speed away from the Platform to a rate which would have been breathless, on Earth. But here there was no sensation of motion, and the distances were enormous. Things which happen in space happen with insensate violence and incredible swiftness. But long, long, long intervals elapse between events. The twelve-two rocket burned out. The Chief had matched that also.

Brown's voice in the headphones said, "The rocket's cut acceleration. It's floating up, now. It should reach our orbit fifty miles behind us. But our missile should hit it in forty seconds."

"I wouldn't bet on that," said Joe coldly. "Figure interception data for the Chief and me. Make it fast!"

He spotted the Chief, a dozen miles away and burning his steering rockets to close, again. The Chief had the hang of it, now. He didn't try to steer. He drove toward Joe.

But nothing happened. And nothing happened. And nothing happened. The two tiny space wagons were 90 miles from the Platform, which was now merely a glittering speck, hardly brighter than the brightest stars.

There was a flare of light to Earthward. It was brighter than the sun. The light vanished.

Brown's voice came in the headphones, "Our missile went off 200 miles short! He sent an interceptor to set it off!"

"Then he's dangerous," said Joe. "There'll be war rockets coming up any second now for him to control from right at hand. We won't be fighting rockets controlled from 4,000 miles away! They've found proximity fuses don't work, so he's going to work in close. Give us our course and data, quick! The Chief and I have got to try to smash things!"

The two tiny space wagons—like stick-insects in form, absurdly painted a brilliant red—seemed inordinately lonely. It was hardly possible to pick out the Platform with the naked eyes. The Earth was thousands of miles below. Joe and the Chief, in space suits, rode tiny metal frameworks in an emptiness more vast, more lonely, more terrible than either could have imagined.

Then the war rockets started up. There were eight of them. They came out to do murder at ten gravities acceleration.