by Anthology
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!"
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 space, but some would be drawn back by the asteroid's slight gravity. The craters would be highly radioactive, and some radioactive debris was certain to 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 calculations. They would be exposed 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 just 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. Spaceships blasted through space 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 spaceship," 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 one bomb for retrothrust, then fire two 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. "After the asteroid is kicked out of orbit, it will fall toward the sun. At our closest approach to the sun, we'll have enough velocity to carry us past safely. Then we'll lose speed constantly until we come into Earth's gravitational field and have to brake."
It was just space 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 space 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 and moved forward. "Sir, may I ask a question?"
Rip turned to face the Planeteer, still worrying over the problem. He nodded and said, "What is it, Dominico?"
"Sir, I think we can't worry too much about this radiation, eh? You will think of some way to take care of it. What I want to ask, sir, is when do we let go the bombs? I do not know much about radiation, but I can set those bombs like you want them."
Rip was touched by the 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. Moving around on a no-weight world was more like skating than walking. A regular walk would have lifted Koa into space with every step. Of course, the asteroid had some gravity, but so little that it hardly mattered.
Rip centered the top of the instrument's vertical hairline on Alpha Centauri, then waited until Koa was almost out of sight over the asteroid's horizon, which was only a few hundred yards away.
He turned up the volume on his helmet communicator. "Koa, move about ten feet to your left."
Koa did so. Rip sighted past the vertical hairline at the belt light. "That's a little too far. Take a small step to the right. That's good ... just a few inches more ... hold it. You're right in position. Stand where you are."
"Yessir."
Rip turned to Santos. "Stand here, Corporal. Take a sight at Koa to get your bearings, then hold position."
Santos did so. Now the two lights gave Rip one of the lines he needed. He called for two more men, and Trudeau and Nunez joined him. "Follow me," he directed.
Rip picked up the instrument and carried it to a point ninety degrees from the line represented by Koa and Santos. He put the instrument down and zeroed it on Messier 44, the Beehive star cluster in the constellation Cancer. For the second sighting star he chose Beta Pyxis as being closest to the line he wanted, made the slight adjustments necessary to set the line of sight, since Pyxis wasn't exactly on it, then directed Trudeau into position as he had Koa. Nunez took position behind the instrument, and Rip had his cross fix.
He called for Dowst, then carried the instrument to the center of the cross formed by the four men. Using the instrument, he rechecked the lines from the center out. They were within a hair or two of being exactly on, and a slight error wouldn't hurt, anyway. He knew he would have to correct with rocket blasts once the asteroid was in the new orbit.
"X marks the spot," he told Dowst. He put his toe on the place where the crosslines met.
Dowst used a spike to make an X in the metal ground.
"All set," Rip announced. "You four men can move now. Let's have the cutting equipment over here, Koa."
The Planeteers were all waiting for instructions now. In a few moments the equipment was ready, fuel and oxygen bottles attached.
"Who's the champion torchman?" Rip asked.
Koa replied, "Kemp is, sir."
Kemp, one of the two American privates, took the torch and waited for orders. "We need a hole six feet across and twenty feet deep," Rip told him. "Go to it."
"How about direction, sir?" Kemp asked.
"Straight down. We'll take a bearing on an overhead star when you're in a few feet."
Dowst inscribed a circle around the X he had made and stood back. Kemp pushed the striker button and the torch flared. "Watch your eyes," he warned. The Planeteers reached for belt controls and turned the rheostats that darkened the clear bubbles electronically. Kemp adjusted his flame until it was blue-white, a knife of fire brighter by far than the light of the sun at this distance.
Koa stepped behind Kemp and leaned against his back, because the flame of the torch was like an exhaust, driving Kemp backward. Kemp bent down, and the torch sliced into the metal of the asteroid like a hot knife into ice. The metal splintered a little as the heat raised it instantly from almost absolute zero to many thousands of degrees.
When the circle was completed, Kemp adjusted his torch again, and the flame lengthened. He moved inside the circle and cut at an angle toward the perimeter. His control was quick and certain. In a moment he stood aside, and Koa lifted out a perfect ring of thorium. It varied from a knife edge on the inner side to eighteen inches on the outer side.
In the middle of the circle there was now a cone of metal. Kemp cut around it, the torch angling toward the center. A piece shaped like two cones set base to base came free. Since the metal cooled in the bitter chill of space almost as fast as Kemp could cut it, there was no heat to worry about.
Alternately cutting from the outside and the center of the hole, Kemp worked his way downward until his head was below ground level. Rip called a halt. Kemp gave a little jump and floated straight upward. Koa caught him and swung him to one side. Rip stepped into the hole, and Santos gave him a slight push to send him to the bottom. Rip knelt and sighted upward. Kemp had done a good job. The star Rip had chosen as a guide was straight overhead.
He bounced out of the hole, and, as Koa caught him, he told Kemp to go ahead. "Dominico, here's your chance. Get tools and wire. Find a timer and connect up the ten-kiloton bomb. Nunez, bring it here while Dominico gets what he needs."
Kemp was burning his way into the asteroid at a good rate. Every few moments he pushed another circle or spindle of thorium out of the hole. Rip directed some of the men to carry them away, to the other side of the asteroid. He didn't want chunks of thorium flying around from the blast.
The sergeant major had a sudden thought. He cut off his communicator, motioned to Rip to do the same, then put his helmet against Rip's for direct communication. He didn't want the others to hear what he had to say. His voice came like a roar from the bottom of a well. "Lieutenant, do you suppose there's any chance the blast might break up the asteroid? Maybe split it in two?"
The same thought had occurred to Rip on the Scorpius. His calculations had showed that the metal would do little more than compress, except where it melted from the terrific heat of the bomb. That would be only in and around the shaft. He was sure the men at Terra base had figured it out before they decided that A-bombs would be necessary to throw the asteroid into a new orbit. He wasn't worried. Cracks in the asteroid would be dangerous, but he hadn't seen any.
"This rock will take more nuclear blasts than we have," he assured Koa. He turned his communicator back on and went to the edge of the hole for a look at Kemp's progress. He was far down now. Pederson was holding one end of a measuring tape. The other end was fastened to Kemp's shoulder strap.
The Swedish corporal showed Rip that he had only about eight feet of tape left. Kemp was almost down. Rip called, "Kemp, when you reach bottom, cut toward the center. Leave an inverted cone."
"Got it, sir. Be up in two more cuts."
Dominico had connected cable to the bomb terminals and was attaching a timer to the other end. Without the wooden case, the bomb was like a fat, oversized can.
It had been shipped without a combat casing.
"Koa, make a final check. You can untie the landing boat, except for one line. We'll be taking off in a few minutes."
"Right, sir." Koa glided toward the landing boat, which was moored out of sight beyond the horizon.
It was nearly time. Rip had a moment's misgiving. Had his figures or his sightings been off? His scalp prickled at the thought. But the ship's computer had done the work, and it was not capable of making a mistake.
Kemp tossed up the last section of thorium and then came out of the hole himself, carrying his torch.
Rip inspected the hole, saw with satisfaction that it was in almost perfect alignment, and ordered the bomb placed. He bent over the edge of the hole and watched Trudeau pay out wire while Dominico pushed the bomb to the bottom. The Italian made a last-minute check, then called to Rip. "Ready, sir."
Rip dropped into the hole and inspected the connections himself, then personally pulled the safety lever. The bomb was armed. When the timer acted, it would go off.