A thousand miles above Earth's surface the great space platform sped from daylight into darkness. Once every two hours it circled the earth completely, spinning along through space like a mighty wheel of steel and plastic.

Through a telescope on Earth the platform looked to be a lifeless, lonely disk, but within it, hundreds of spacemen and Planeteers went about their work.

In a ready room at the outer edge of the platform, a Planeteer officer faced a dozen slim, black-clad young men who wore the single golden orbits of lieutenants. This was a graduating class, already commissioned, having a final informal get-together.

The officer, who wore the three-orbit insignia of a major, was lean and trim. His short-cropped hair covered his head like a gray fur skull cap. One cheek was marked with the crisp whiteness of an old radiation burn.

"Stand easy," he ordered briskly. "The general instructions of the Special Order Squadrons say that it's my duty as senior officer to make a farewell speech. I intend to make a speech if it kills me—and you, too."

The dozen new officers facing him broke into grins. Maj. Joe Barris had been their friend, teacher, and senior officer during six long years of training on the space platform. He could no more make a formal speech than he could breathe high vacuum, and they all knew it.

Lt. Richard Ingalls Peter Foster, whose initials had given him the nickname "Rip," asked, "Why don't you sing for us instead, Joe?"

Major Barris fixed Rip with a cold eye. "Foster, three orbital turns, then front and center."

Rip obediently spun around three times, then walked forward and stood at attention, trying to conceal his grin.

"Foster, what does SOS mean?"

"Special Order Squadrons, sir."

"Right. And what else does it mean?"

"It means 'Help!' sir."

"Right. And what else does it mean?"

"Superman or simp, sir."

This was a ceremony in which questions and answers never changed. It was supposed to make Planeteer cadets and junior officers feel properly humble, but it didn't work. By tradition, the Planeteers were the cockiest gang that ever blasted through high vacuum.

Major Barris shook his head sadly. "You admit you're a simp, Foster. The rest of you are simps, too, but you don't believe it. You've finished six years on the platform. You've made a few little trips out into space. You've landed on the moon a couple of times. So now you think you're seasoned space spooks. Well, you're not. You're simps!"

Rip stopped grinning. He had heard this before. It was part of the routine. But he sensed that this time Joe Barris wasn't kidding.

The major absently rubbed the radiation scar on his cheek as he looked them over. They were like twelve chicks out of the same nest. They were about the same size, a compact five feet eleven inches, 175 pounds. They wore belted, loose black tunics over full trousers which gathered into white cruiser boots. The comfortable uniforms concealed any slight differences in build. All twelve were lean of face, with hair cropped to the regulation half inch. Rip was the only redhead among them.

"Sit down," Barris commanded. "Here's my speech."

The twelve seated themselves on plastic stools. Major Barris remained standing.

"Well," he began soberly, "you are now officers of the Special Order Squadrons. You're Planeteers. You are lieutenants by order of the Space Council, Federation of Free Governments. And—space protect you!—to yourselves you're supermen. But never forget this: To ordinary spacemen, you're just plain simps. You're trouble in a black tunic. They have about as much use for you as they have for leaks in their air locks. Some of the spacemen have been high-vacking for twenty years or more, and they're tough. They're as nasty as a Callistan teekal. They like to eat Planeteer junior officers for breakfast."

Lt. Felipe "Flip" Villa asked, "With salt, Joe?"

Major Barris sighed. "No use trying to tell you space chicks anything. You're lieutenants now, and a lieutenant has the thickest skull of any rank, no matter what service he belongs to."

Rip realized that Barris had not been joking, no matter how flippant his speech. "Go ahead," he urged. "Finish what you were going to say."

"Okay. I'll make it short. Then you can catch the Terra rocket and take your eight weeks' Earth leave. You won't really know what I'm talking about until you've batted around space for a while. All I have to say adds up to one thing. You won't like it, because it doesn't sound scientific. That doesn't mean it isn't good science, because it is. Just remember this: When you're in a jam, trust your hunch and not your head."

The twelve stared at him, openmouthed. For six years they had been taught to rely on scientific methods. Now their best instructor and senior officer was telling them just the opposite!

Rip started to object, but then he caught a glimmer of meaning. He stuck out his hand. "Thanks, Joe. I hope we'll meet again."

Barris grinned. "We will, Rip. I'll ask for you as a platoon commander when they assign me to cleaning up the goopies on Ganymede." This was the major's idea of the worst Planeteer job in the solar system.

The group shook hands all around; then the young officers broke for the door on the run. The Terra rocket was blasting off in five minutes, and they were to be on it.

Rip joined Flip Villa, and they jumped on the high-speed track that would whisk them to Valve Two on the other side of the platform. Their gear was already loaded. They had only to take seats on the rocket, and their six years on the space platform would be at an end.

"I wonder what it will be like to get back to high gravity," Rip mused. The centrifugal force of the spinning platform acted as artificial gravity, but it was considerably less than Earth's.

"We probably won't be able to walk straight until we get our Earth legs back," Flip answered. "I wish I could stay in Colorado with you instead of going back to Mexico City, Rip. We could have a lot of fun in eight weeks."

Rip nodded. "Tough luck, Flip. But anyway, we have the same assignment."

Both Planeteers had been assigned to Special Order Squadron Four, which was attached to the cruiser Bolide. The cruiser was in high space, beyond the orbits of Jupiter and Saturn, doing comet research.

They got off the track at Valve Two and stepped through into the rocket's interior. Two seats just ahead of the fins were vacant, and they slid into them. Rip looked through the thick port beside him and saw the distinctive blue glow of a nuclear drive cruiser sliding toward the platform.

"Wave your eye stalks at that job," Flip said admiringly. "Wonder what it's doing here."

The space platform was a refueling depot, where conventional chemical fuel rockets topped off their tanks before flaming for space. The newer nuclear drive cruisers had no need to stop. Their atomic piles needed new neutron sources only once every few years, and they carried thousands of tons of methane, compressed into solid form, for their reaction mass.

The voice horn in the rocket cabin sounded. "The SCN Scorpius is passing Valve Two, landing at Valve Eight."

"I thought that ship was with Squadron One on Mercury," Rip recalled. "Wonder why they pulled it back here."

Flip had no chance to reply, because the chief rocket officer took up his station at the valve and began to call the roll. Rip answered to his name.

The rocket officer finished the roll, then announced: "Buttoning up in twenty seconds. Blast off in forty-five. Don't bother with acceleration harness. We'll fall free, with just enough flame going for control, after ten seconds of retrothrust to de-orbit."

The ten-second-warning bell sounded, and, before the bell had ceased, the voice horn blasted. "Get it! Foster, R.I.P., Lieutenant. Report to the platform commander. Show an exhaust!"

Rip leaped to his feet. "Hold on, Flip. I'll see what the old man wants and be right back."

"Get flaming," the rocket officer called. "Show an exhaust, like the man said. This bucket leaves on time, and we're sealing the port."

Rip hesitated. The rocket would leave without him!

Flip said urgently, "You better ram it, Rip."

He knew he had no choice. "Tell my folks I'll make the next rocket," he called, and ran. He leaped through the valve, jumped for the high-speed track, and was whisked around the rim of the space platform.

He ran a hand through his short red hair, a gesture of bewilderment. His records had cleared. So far as he knew, all his papers were in order, and he had his next assignment. He couldn't figure why the platform commander would want to see him. But the horn had called, "Show an exhaust!" which meant to get there in a hurry.

He jumped off the track at the main crossrun and hurried toward the center of the platform. In a moment he was at the commander's door, waiting to be identified.

The door swung open, and a junior officer in the blue tunic and trousers of a spaceman motioned him to the inner room. "Go in, Lieutenant."

"Thank you." He hurried into the commander's room and stood at attention.

Commander Jennsen, the Norwegian spaceman who had commanded the platform since before Rip's arrival as a raw cadet, was dictating into his command relay circuit. As he spoke, printed copies were being received in the platform personnel office, at Special Order Squadron headquarters on Earth, aboard the cruiser Bolide in high space, and aboard the newly landed cruiser Scorpius.

Rip listened, spellbound.

"Foster, R.I.P., Lieutenant, SOS. Serial seven-nine-four-three. Assigned SOS Four. Change orders, effective this date-time. Cancel Earth leave. Subject officer will report to commander, SCN Scorpius, with detachment of nine men. Senior noncommissioned officer and second in command, Koa, A.P., Sergeant Major, SOS. Serial two-nine-four-one. Commander of Scorpius will transport detachment to coordinates given in basic cruiser astro-course; deliver orders to detachment en route. Take required steps for maximum security. This is Federation priority A, Space Council security procedures."

Rip swallowed hard. The highest possible priority, given by the Federation itself, had canceled his leave. Not only that, but the cruiser to which he was assigned was instructed to follow Space Council security procedures, which meant that the job, whatever it was, was more urgent than secret!

Commander Jennsen looked up and saw Rip waiting. He snapped, "Did you get all of that?"

"Y-Yes, sir."

"You'll get written copies on the cruiser. Now flame out of here. Collect your men and get aboard. The Scorpius leaves in five minutes."

Rip ran. The realization hit him that the big nuclear cruiser had stopped at the platform for the sole purpose of collecting him and nine enlisted Planeteers.

The low gravity helped him cover the hundred yards to the personnel office in five leaps. He swung to a stop by grabbing the push bar of the office door. He yelled at the enlisted spaceman on duty. "Where do I find nine men?"

The spaceman looked at him vacantly. "What for? You got a requisition, Lieutenant?"

"Never mind requisitions," Rip snapped. "I've got to find nine Planeteers and get them on the Scorpius before it flames off."

The spaceman's face cleared. "Oh. You mean Koa's detachment. They left a few minutes ago."

"Where. Where did they go?"

The spaceman shrugged. The doings of Planeteers were no concern of his. His shrug said so.

Rip realized there was no use talking further. He ran down the long corridor toward the outer edge of the platform. The enlisted men's squad rooms were near Valve Ten. So was the supply department. His gear had departed on the Terra rocket, and he couldn't go into space with only the tunic on his back. He swung to the high-speed track and braced himself as he sped along the platform's rim.

There was no moving track inward to the enlisted Planeteers' squad rooms. He legged it down the corridor in long leaps, muttering apologies as blue-clad spacemen and cadets moved to the wall to let him pass.

The squad rooms were on two levels. He looked in the upper ones and found them deserted. The squads were on duty somewhere. He ran for the ladder to the lower level, took the wrong one, and ended up in a snapper-boat port. He had trained in the deadly little fighting rockets, and they never failed to interest him. But there wasn't time to admire them now. He went back up the ladder with two strong heaves, found the right ladder, and dropped down without touching. His knees flexed to take up the shock. He came out of the crouch facing a black-clad Planeteer sergeant who snapped to rigid attention.

"Koa," Rip barked. "Where can I find him?"

"He's not here, sir. He and eight men left fifteen minutes ago. I don't know where they went, sir."

Rip shot a worried glance at his wrist chronometer. He had two minutes left before the cruiser departed. No more time now to search for his men. He hoped the sergeant major had sense enough to be waiting at some reasonable place. He went up the ladder hand over hand and sped down the corridor to the supply room. The spaceman first class in charge of supplies was turning an audio-mag through a hand viewer, chuckling at the cartoons. At the sight of Rip's flushed, anxious face he dropped the machine. "Yessir?"

"I need a spack. Full gear, including bubble."

"Yessir." The spaceman looked him over with a practiced eye. "One full space pack. Medium-large, right, sir?"

"Correct." Rip took the counter stylus and inscribed his name, serial number, and signature on the blank plastic sheet. Gears whirred as the data was recorded.

The spaceman vanished into an inner room and reappeared in a moment lugging a plastic case called a space pack, or "spack" for short. It contained complete personal equipment for space travel. Rip grabbed it. "Fast service. Thanks, Rocky." All spacemen were called "Rocky" if you didn't know their names. It was an abbreviation for rocketeer, a title all of them had once carried.

Valve Eight was some distance away. Rip decided a cross ramp would be faster than the moving track. He swung the spack to his shoulder and made his legs go. Seconds were ticking off, and he had an idea that the SCN Scorpius would make space on time, whether or not he arrived. He lengthened his stride and rounded a turn by going right up on the wall, using a powerful leg thrust against a ventilator tube for momentum.

He passed an observation port as he reached the platform rim, and caught a glimpse of ruddy rocket exhaust flames outlined against the dark curve of Earth. That would be the Terra rocket making its controlled fall to home, with Flip aboard. Without slowing, he leaped across the high-speed track, narrowly missing a senior space officer. He shouted his apologies, and gained the entrance to Valve Eight just as the high buzz of the radiation warning sounded, signaling a nuclear drive cruiser preparing to take off.

Nine faces of assorted colors and expressions turned to him. He had a quick impression of black tunics and trousers. He had found his detachment! Without slowing, he called, "Follow me!"

The cruiser's safety officer had been keeping an eye on the clock, his forehead creased in a frown as he saw that only a few seconds remained to departure time. He walked to the valve opening and looked out. If his passengers were not in sight, he would have to reset the clock.

Rip went through the valve opening at top speed. He crashed head on into the safety officer.

The safety officer was driven across the deck, his arms pumping for balance. He grabbed at the nearest thing, which happened to be the deputy cruiser commander.

The preset clock reached firing time. The valve slid shut and the takeoff bell reverberated through the ship.

And so it happened that the spacemen of the SCN Scorpius turned their valves, threw their controls and disengaged their boron control rods, and the great cruiser flashed into space—while the deputy commander and the safety officer were completely tangled with a very flustered and unhappy new Planeteer lieutenant.

Sergeant Major Koa and his men had made it before the valve closed. Koa, a seven-foot Hawaiian, took in the situation and said crisply in a voice all could hear, "I'll bust the bubble of any son of a space sausage who laughs!"