Rip rechecked his space suit before putting on his helmet. The air seal was intact, and his heating and ventilating units worked. He slapped his knee pouches to make sure the space knife was handy to his left hand, the pistol to his right.

Koa was already fully dressed. He handed Rip the shoulder case that contained the plotting board. Santos had taken charge of Rip's astrogation instruments.

A spaceman was waiting with Rip's bubble. At a nod, the spaceman slipped it on his head. Rip reached up and gave it a quarter turn. The locking mechanism clamped into place. He turned his belt ventilator control on full, and the space suit puffed out. When it was fully inflated, he watched the pressure gauge. It was steady. No leaks in suit or helmet. He let the pressure go down to normal.

Koa's voice buzzed in his ears. "Hear me, sir?"

Rip adjusted the volume of his communicator and replied, "I hear you. Am I clear?"

"Yessir. All men dressed and ready."

Rip made a final check. He counted his men, then personally inspected their suits. The boats were next. They were typical landing craft, shaped like rectangular boxes. There was no need for streamlining in the vacuum of space. They were not pressurized. Only men in space suits rode in the ungainly boxes.

He checked all blast tubes to make sure they were clear. There were small single tubes on each side of the craft. A clogged one could explode and blow the boat up.

Koa, he knew, had checked everything, but the final responsibility was his. In space, no officer took anyone's word for anything that might mean lives. Each checked every detail personally.

Rip looked around and saw the Planeteers watching him. There was approval on the faces behind the clear helmets, and he knew they were satisfied with his thoroughness.

At last, certain that everything was in good order, he said quietly, "Pilots, man your boats."

Dowst got into one and a spaceman into the other. Dowst's boat would stay with them on the asteroid. The spaceman would bring the other back to the ship.

Commander O'Brine stepped through the valve into the boat lock. A spaceman handed him a hand communicator. He spoke into it. Rip couldn't have heard him through the helmet otherwise. "All set, Foster?"

"Ready, sir."

"Good. The long-range screen picked up a blip a few minutes ago. It's probably that Connie cruiser."

Rip swallowed. The Planeteers froze, waiting for the commander's next words.

"Our screens are a little better than theirs, so there's a slim chance they haven't picked us up yet. We'll drop you and get out of here. But don't worry. We have your orbit fixed, and we'll find you when the screens are clear."

"Suppose they find us while you're gone?" Rip said.

"It's a chance," O'Brine admitted. "You'll have to take spaceman's luck on that one. But we won't be far away. We'll duck behind Vesta, or another of the big asteroids, and hide so their screens won't pick up our motion. Every now and then we'll sneak out for a look, if the screen seems clear. If those high-vack vermin do find you, get on the landing-boat radio and yell for help. We'll come blasting."

He waved a hand, thumb and forefinger held together in the ancient symbol for "everything right," then ordered, "Get flaming." He stepped through the valve.

"Clear the lock," Rip ordered. "Open outer valve when ready."

He took a quick, final look around. The pilots were in the boats. His Planeteers were standing by, safety lines already attached to the boats and their belts. He moved into position and snapped his own line to a ring on Dowst's boat. The spacemen vanished through the valve, and the massive door slid closed. The overhead lights flicked out. Rip now snapped on his belt light, and the others followed suit.

In front of the boxlike landing boats a great door slid open, and air from the lock rushed out. Rip knew it was only imagination, but he felt as though all the heat from his suit was radiating into space, chilling him to near absolute zero. Beyond the lights from their belts, he saw stars and recognized the constellation for which the space cruiser was named. A superstitious spaceman would have taken that as a good sign. Rip admitted that it was nice to see.

"Float 'em," he ordered.

The Planeteers gripped handholds at the entrance with one hand and launching rails on the boats with the other, then heaved. The boats slid into space. As the safety lines tightened, the Planeteers were pulled after the boat.

Rip left his feet with a little spring and shot through the door. Directly below him, the asteroid gleamed darkly in the light of the tiny sun. His first reaction was "Great Cosmos! What a little chunk of rock!" But that was because he was used to looking from the space platform at the great curve of Terra or at the big ball of the moon. Actually the asteroid was fair-sized, when compared with most of its kind.

The Planeteers hauled themselves into the boats by their safety lines. Rip waited until all were in, then pulled himself along his own line to the black square of the door. Koa was waiting to give him a hand into the craft.

The Planeteers were standing, except for Dowst. Rip had never seen an old-type railroad, or he might have likened the landing boat to a railroad boxcar. It was about the same size and shape, but had huge "windows" on both sides and in front of the pilot—windows that were not enclosed. The space-suited men needed no protection.

"Blast," Rip ordered.

A pulse of fire spurted from the top of each boat, driving them bottom first toward the asteroid.

"Land at will," Rip said.

The asteroid loomed large as he looked through an opening. It was rocky, but there were plenty of smooth places.

Dowst picked one. He was an expert pilot, and Rip watched him with pleasure. The exhaust from the top lessened, and fire spurted soundlessly from the bottom. Dowst balanced the opposite thrusts of the top and bottom blasts with the delicacy of a woman threading a needle. In a few moments the boat was hovering a foot above the asteroid. Dowst cut the exhausts, and Rip stepped out onto the tiny planet.

The Planeteers knew what to do. Corporal Pederson produced hardened steel spikes with ring tops. Private Trudeau had a sledge. Driving the first spike would be the hardest, because the action of swinging the hammer would propel the Planeteer like a rocket exhaust. In space, the law that every action has an equal and opposite reaction had to be remembered every moment.

Rip watched, interested in how his man would tackle the problem. He didn't know the answer himself, because he had never driven a spike on an airless world with almost no gravity, and no one had ever mentioned it to him.

Pederson searched the gray metal with his torch and found a slender spur of thorium, perhaps two feet high, a short distance from the boat. "Here's a hold," he said. "Come on, Frenchy. You too, Bradshaw."

Trudeau, carrying the sledge, walked up to the spur of rock and stood with his heels against it. Pederson sat down on the ground with his legs on either side of the spur. He stretched, hooking his heels around Trudeau's ankles, anchoring him. With his gloves, he grabbed the seat of the Frenchman's space suit.

Bradshaw took a spike and held it against the gray metal ground. The Frenchman swung, his hammer noiseless as it drove the tough spike. A few inches into the metal was enough. Bradshaw took a wrench from his belt, put it on the head of the spike, and turned it. Below the surface, teeth on the spike bit into the metal. It would hold.

The rest was easy. The spike was used to anchor Trudeau while he drove another, at his longest reach. Then the second spike became his anchor, and so on, until enough spikes had been set to lace the boat down against any sudden shock.

The boat piloted by the spaceman was tied to the one that would remain, and the Planeteers floated its supplies through a window. It took only a few moments, with Planeteers forming a chain from inside the boat to a spot a little distance away. The crates weighed almost nothing, but still retained their mass. Once their inertia was overcome, they moved from one man to the next like ungainly balloons.

"All clear, sir," Koa called.

Rip stepped inside and made a quick inspection. The box was empty except for the spaceman pilot. He put a hand on the pilot's shoulder. "On your way, Rocky. Thanks."

"You're welcome, sir." The pilot added, "Watch out for high vack."

Rip and Koa stepped out and walked a little distance away. Santos and Pederson cast the landing boat adrift and shoved it away from the anchored boat. In a moment fire spurted from the bottom tube, spreading over the dull metal and licking at the feet of the Planeteers.

Rip watched the boat rise upward to the great, sleek, dark bulk of the Scorpius. The landing boat maneuvered into the air lock with brief flares from its exhausts. In a few moments the sparkling blast of auxiliary rocket tubes moved the spaceship away. O'Brine was putting a little distance between his ship and the asteroid before turning on the nuclear drive. The ship decreased in size until Rip saw it only as a dark, oval silhouette against the Milky Way. Then the exhaust of the nuclear drive grew into a mighty column of glowing blue, and the ship flamed into space.

For a moment Rip had a wild impulse to yell for the ship to come back. He had been in vacuum before, but only as a cadet, with an officer in charge. Now, suddenly, he was the one responsible. The job was his. He stiffened. Planeteer officers didn't worry about things like that. He forced his mind to the job at hand.

The next step was to establish a base. The base would have to be on the dark side of the asteroid, once it was in its new orbit. That meant a temporary base now and a better one later, when they had blasted the little planet into its new course. He estimated roughly the approximate positions where he would place his charges, using the sun and the star Canopus as visual guides.

"This will do for a temporary base," he announced. "Rig the boat compartment. While two of you are doing that, you others break out the rocket launcher and rocket racks and assemble the cutting torch. Koa will make assignments."

While the sergeant major translated Rip's general instructions into specific orders for each man, the young lieutenant walked to the edge of the sun belt. There was no atmosphere, so the edge was a sharp line between dark and light. There wasn't much light, either. They were too far from the sun for that. But as they neared the sun, the darkness would be their protection. They would get so close to Sol that the metal on the sun side would get soft as butter.

He bent close to the uneven surface. It was clean metal, not oxidized at all. The thorium had never been exposed to oxygen. Here and there, pyramids of metal thrust up from the asteroid, sometimes singly, sometimes in clusters. They were metal crystal formations. He guessed that once, long ages ago, the asteroid had been a part of something much bigger, perhaps a planet. One theory said the asteroids were formed when a planet exploded. This asteroid might have been a pocket of pure thorium in the planet.

There would be plenty to do in a short while, but meanwhile he enjoyed the sensation of being on a tiny world in space with only a handful of Planeteers for company. He smiled. "King Foster," he said to himself. "Monarch of a thorium space speck." It was a rather nice feeling, even though he laughed at himself for thinking it. Since he was in command of the detachment, he could in all truth say that this was his own personal planet. It would be a good bit of space humor to spring on the folks back on Terra.

"Yep, once I was boss of a whole world. Made myself king. Emperor of all the metal molecules and king of the thorium spurs. And my subjects obeyed my every command." He added, "Thanks to Planeteer discipline. The detachment commander is boss."

He reminded himself that he had better stop gathering space dust and start acting like a detachment commander. He walked back to the landing boat, stepping with care. With such low gravity, a false step could send him high above the asteroid. Of course, that would not be dangerous, since space suits were equipped with six small compressed-air bottles for emergency propulsion. But it would be embarrassing.

Inside the boat, Dowst and Nunez were setting up the compartment. Sections of the rear wall swung out and locked into place against airtight seals, forming a box at the rear end of the boat. Equipment sealed in the stern, next to the rocket tube, supplied light, heat, and air. It was a simple but necessary arrangement. Without it, the Planeteers could not have eaten.

There was no air lock for the compartment. The half of the detachment not on duty would walk in, seal it up, turn on the equipment, wait until the gauges registered sufficient air and heat, and then remove their space suits. When it was time to leave, they would don suits, open the door, and walk out, and the next shift would enter and repeat the process. Earlier models had permanent compartments, but they took up too much room in craft designed for carrying as many men and as much equipment as possible. They were strictly work boats, and hard experience had dictated the best design.

The rocket launcher was already set up near the boat. It was a simple affair, with three adjustable legs bolted to ground spikes. The legs held a movable cradle in which the rocket racks were placed. High-geared hand controls enabled the gunner to swing the cradle at high speed in any direction except straight down. A simple, illuminated optical sight was all the gunner needed. Since there were neither gravity nor atmosphere in space, the missiles flashed out in a straight line, continuing on into infinity if they missed their targets. Proximity fuses made this a remote possibility. If the rocket got anywhere near the target, the shell would explode.

Rip found his astrogation instruments set carefully to one side. He removed the data sheets from his case and examined them. Now came the work of finding the spots in which to place his atomic charges. Since the computer aboard ship had done all the mathematics necessary, he needed only to take sights to determine the precise positions.

He took a transit-like instrument from the case, pulled out the legs of its self-contained tripod, then carried it to a spot near where he had estimated the first charge would be placed. The instrument was equipped with three movable rings to be set for the celestial equator, for the zero meridian, and for the right ascension of any convenient star. Using a regular level would have been much simpler. The instrument had one, but with so little gravity to activate it, the thing was useless.

The sights were specially designed for use in space, and his bubble was no obstacle in taking observations. He merely put the clear plastic against the curved sight and looked into it much as he would have looked through a telescope on Earth.

As he did so, a hint of pale pink light caught the corner of his eye. He backed away from the instrument and turned his head quickly, looking at the colorimeter-type radiation detector at the side of his helmet. It was glowing.

An icy chill sent a shiver through him. Great, gorgeous galaxies! He had forgotten ... had Koa and the others? He turned so fast that he lost his balance and floated above the surface like a captive balloon. Santos, who had been standing nearby to help if requested, hooked a toe on the ground spike, caught him, and set him upright on the ground again.

"Get me the radiation detection instruments," he ordered.

Koa sensed the urgency in his voice and got the instruments himself. Rip switched them on and read the illuminated dial on the alpha counter. Plenty high, as was natural. But no danger there—alpha particles couldn't penetrate the space suits. Then, his hand clammy inside the space glove, he switched on the other meter. The gamma count was far below the alpha, but there were too many of the rays around for comfort. Inside the helmet his face turned pale.

There was no immediate danger. It would take many days to build up a dose of gamma that could hurt them. But gamma was not the only radiation. They were in space, fully exposed to equally dangerous cosmic radiation.

The Planeteers had gathered while he read the instruments. Now they stood watching him.

They knew the significance of what he had found.

"I ought to be busted to recruit," he told them. "I knew this asteroid was thorium and that thorium is radioactive. If I had used my head, I would have added nuclite shielding to the list of supplies the Scorpius provided. We could have had enough of it to protect us while around our base, even if we couldn't be protected while working on the charges. That would at least have kept our dosage down enough for safety."

"No one else thought of it, either, sir," Koa reminded him.

"It was my job to think of it, and I didn't. So I've put us in a time squeeze. If the Scorpius gets back soon, we can get the shielding before our radiation dosage has built up very high. If the ship doesn't come back, the dosage will mount."

He looked at them grimly. "It won't kill us, and it won't even make us very sick. I'll have the ship take us off before we build up that much dosage."

Santos started. "But, sir! That means—"

"I know what it means," Rip stated bitterly. "It means the ship has got to return in time to give us some nuclite shielding, or we'll be the laughingstock of the Special Order Squadrons—the detachment that started a job the spacemen had to finish!"