There would be plenty to do in a short while, but meanwhile he enjoyed the sensation of being on a tiny world in s.p.a.ce with only a handful of Planeteers for company. He smiled. "King Foster," he said to himself.

"Monarch of a thorium s.p.a.ce 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 this was his own personal planet. It would be a good bit of s.p.a.ce humor to spring on the folks back on Terra.

"Yep, I was boss of a whole world, once. 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'd better stop gathering s.p.a.cedust 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 the s.p.a.ce suits were equipped with six small compressed air bottles for emergency propulsion. But it would be embarra.s.sing.

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, and wait until the gauges registered sufficient air and heat, then remove their s.p.a.ce suits. When it was time to leave again, 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 showed the best design.

The rocket launcher was already set up near the boat. It was a simple affair, with four 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 was no gravity and no atmosphere in s.p.a.ce, 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 sh.e.l.l would explode.

Rip found his astrogation instruments set carefully to one side. He took the data sheets from his case and examined them. Now came the work of finding the exact 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 s.p.a.ce 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 he lost balance and floated above the surface like a captive balloon. Santos, who had been standing near by to help if requested, hooked a toe on a 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 s.p.a.ce suits. Then, his hand clammy inside the s.p.a.ce 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 s.p.a.ce, 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 nuc.l.i.te 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.

"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 nuc.l.i.te shielding, or we'll be the laughingstock of the Special Order Squadrons-the detachment that started a job the s.p.a.cemen had to finish!"

CHAPTER SEVEN - EARTHBOUND!

There was something else that Rip didn't add, although he knew the Planeteers would realize it in a few minutes. Probably some of them already had thought of it.

To move the asteroid into a new orbit, they were going to fire nuclear bombs. Most of the highly radioactive fission products would be blown into s.p.a.ce, but some would be drawn back by the asteroid's slight gravity. The craters would be highly radioactive and some radioactive debris would be scattered around, too. Every particle would add to the problem.

"Is there anything we can do, sir?" Koa asked.

Rip shook his head inside the transparent bubble. "If you have a good luck charm in your pocket, you might talk to it. That's about all."

Nuclear physics had been part of his training. He read the gamma meter again and did some quick mental calculations. They would be exposed to radiation for the entire trip, at a daily dosage of-

Koa interrupted his train of thought. Evidently the sergeant-major had been doing some calculations of his own. "How long will we be on this rock, sir? You've never told us how long the trip will take."

Rip said quietly, "With luck, it will take us a little more than three weeks."

He could see their faces faintly in the dim sunlight. They were shocked.

s.p.a.ce ships blasted through s.p.a.ce between the inner planets in a matter of hours. The nuclear drive cruisers, which could approach almost half the speed of light, had brought even distant Pluto within easy reach. The inner planets could be covered in a matter of minutes on a straight speed run, although to take off from one and land on the other meant considerable time used in acceleration and deceleration.

The Planeteers were used to such speed. Hearing that it would take over three weeks to reach earth had jarred them.

"This piece of metal isn't a s.p.a.ce ship," Rip reminded them. "At the moment, our speed around the sun is just slightly more than ten miles a second. If we just shifted orbits and kept the same speed, it would take us months to reach Terra. But we'll use two bombs to kick the asteroid into the orbit, then fire one to increase speed. The estimate is that we'll push up to about forty miles a second."

Koa spoke up. "That's not bad when you think that Mercury is the fastest planet and it only makes about thirty miles a second."

"Right," Rip agreed. "And when we really have the sun's gravity pulling us, we'll increase speed. We'll lose a little after we pa.s.s the sun, but by then we'll be almost home."

It was just s.p.a.ce luck that Terra was on the other side of the sun from the asteroid's present position. By the time they approached, it would be in a good place, just far enough from the line to the sun to avoid changing course. Of course Rip's planned orbit was not aiming the asteroid at earth, but at where earth would be at the end of the trip.

"That means more than three weeks of radiation, then," Corporal Santos observed. "Can we take it, sir?"

Rip shrugged, but the gesture couldn't be seen inside his s.p.a.ce suit. "At the rate we're getting radiation now, plus what I estimate we'll get from the nuclear explosions, we'll get the maximum safety limit in just three weeks. That leaves us no margin, even if we risk getting radiation sickness. So we have to get shielding pretty soon. If we do, we can last the trip."

Private Dominico saluted, clumsy in his s.p.a.ce suit. "Sir, I ask permission to speak."

Rip hid a smile at the little Italian's formal manner. In s.p.a.ce, formality was forgotten. "What is it, Dominico?"

"Sir, I think we not worry so much about this radiation, eh? You will think of some ways to take care of it, sir. What I want to ask, sir, is when do we let go the bombs? Radiation I do not know much about, but I can set those bombs like you want them."

Rip was touched by the Italian Planeteer's faith in his ability to solve the radiation problem. That was why being an officer in the Special Order Squadrons was so challenging. The men knew the kind of training their officers had and they expected them to come up with technical solutions as the situation required.

"You'll have a chance to set the bombs in just a short while," he said crisply. "Let's get busy. Koa, load all bombs but one ten KT on the landing boat. Stake the rest of the equipment down. While you're doing that, I'll find the spots where we plant the charges. I'll need two men now and more later."

He went back to his instrument, putting the radiation problem out of his mind-a rather hard thing to do with the colorimeter glowing pink next to his shoulder. Koa detailed men to load the nuclear bombs into the landing craft, left Pederson to supervise, and then brought Santos with him to help Rip.

"The bombs are being put on the boat, sir," Koa reported.

"Fine. There isn't too much chance of the blasts setting them off, but we'll take no chances at all. Koa, I'm going to shoot a line straight out toward Alpha Centauri. You walk that way and turn on your belt light. I'll tell you which way to move."

He adjusted his sighting rings while the sergeant-major glided away.