CHAPTER SEVEN - EARTHBOUND!
There was something else that Rip didn't add, although he knew thePlaneteers would realize it in a few minutes. Probably some of themalready had thought of it.
To move the asteroid into a new orbit, they were going to fire nuclearbombs. Most of the highly radioactive fission products would be blown intospace, but some would be drawn back by the asteroid's slight gravity. Thecraters would be highly radioactive and some radioactive debris would bescattered 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 luckcharm in your pocket, you might talk to it. That's about all."
Nuclear physics had been part of his training. He read the gamma meteragain and did some quick mental calculations. They would be exposed toradiation for the entire trip, at a daily dosage of--
Koa interrupted his train of thought. Evidently the sergeant-major hadbeen doing some calculations of his own. "How long will we be on thisrock, 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 threeweeks."
He could see their faces faintly in the dim sunlight. They were shocked.Space ships blasted through space between the inner planets in a matter ofhours. The nuclear drive cruisers, which could approach almost half thespeed of light, had brought even distant Pluto within easy reach. Theinner planets could be covered in a matter of minutes on a straight speedrun, although to take off from one and land on the other meantconsiderable time used in acceleration and deceleration.
The Planeteers were used to such speed. Hearing that it would take overthree weeks to reach earth had jarred them.
"This piece of metal isn't a space ship," Rip reminded them. "At themoment, our speed around the sun is just slightly more than ten miles asecond. If we just shifted orbits and kept the same speed, it would takeus months to reach Terra. But we'll use two bombs to kick the asteroidinto the orbit, then fire one to increase speed. The estimate is thatwe'll push up to about forty miles a second."
Koa spoke up. "That's not bad when you think that Mercury is the fastestplanet and it only makes about thirty miles a second."
"Right," Rip agreed. "And when we really have the sun's gravity pullingus, we'll increase speed. We'll lose a little after we pass the sun, butby then we'll be almost home."
It was just space luck that Terra was on the other side of the sun fromthe asteroid's present position. By the time they approached, it would bein a good place, just far enough from the line to the sun to avoidchanging course. Of course Rip's planned orbit was not aiming the asteroidat earth, but at where earth would be at the end of the trip.
"That means more than three weeks of radiation, then," Corporal Santosobserved. "Can we take it, sir?"
Rip shrugged, but the gesture couldn't be seen inside his space suit. "Atthe rate we're getting radiation now, plus what I estimate we'll get fromthe nuclear explosions, we'll get the maximum safety limit in just threeweeks. That leaves us no margin, even if we risk getting radiationsickness. So we have to get shielding pretty soon. If we do, we can lastthe trip."
Private Dominico saluted, clumsy in his space suit. "Sir, I ask permissionto speak."
Rip hid a smile at the little Italian's formal manner. In space, formalitywas forgotten. "What is it, Dominico?"
"Sir, I think we not worry so much about this radiation, eh? You willthink of some ways to take care of it, sir. What I want to ask, sir, iswhen do we let go the bombs? Radiation I do not know much about, but I canset those bombs like you want them."
Rip was touched by the Italian Planeteer's faith in his ability to solvethe radiation problem. That was why being an officer in the Special OrderSquadrons was so challenging. The men knew the kind of training theirofficers had and they expected them to come up with technical solutions asthe situation required.
"You'll have a chance to set the bombs in just a short while," he saidcrisply. "Let's get busy. Koa, load all bombs but one ten KT on thelanding boat. Stake the rest of the equipment down. While you're doingthat, I'll find the spots where we plant the charges. I'll need two mennow and more later."
He went back to his instrument, putting the radiation problem out of hismind--a rather hard thing to do with the colorimeter glowing pink next tohis shoulder. Koa detailed men to load the nuclear bombs into the landingcraft, left Pederson to supervise, and then brought Santos with him tohelp 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, butwe'll take no chances at all. Koa, I'm going to shoot a line straight outtoward Alpha Centauri. You walk that way and turn on your belt light. I'lltell 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. Aregular walk would have lifted Koa into space with every step. Of coursethe asteroid had some gravity, but it was so slight that it didn't count.
Rip centered the top of the instrument's vertical hair line on AlphaCentauri, then waited until Koa was almost out of sight over theasteroid's horizon, which was only a few hundred yards away.
He turned up the volume on his helmet communicator. "Koa, move about tenfeet 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. Good ... just afew inches more ... hold it. You're right in position. Stand where youare."
"Yessir."
Rip turned to Santos. "Stand here, Corporal. Take a sight at Koa throughthe instrument to get your bearings, then hold position."
Santos did so. Now the two lights gave Rip one of the lines he needed. Hecalled for two more men, and Trudeau and Nunez joined him. "Follow me," hedirected.
Rip picked up the instrument and carried it to a point 90 degrees from theline represented by Koa and Santos. He put the instrument down and zeroedit on Messier 44, the Beehive star cluster in the constellation Cancer.For the second sighting star he chose Beta Pyxis as being closest to theline he wanted, made the slight adjustments necessary to set the line ofsight since Pyxis wasn't exactly on it, then directed Trudeau intoposition as he had Koa. Nunez took position behind the instrument and Riphad the cross-fix he wanted.
He called for Dowst, then carried the instrument to the center of thecross formed by the four men. Using the instrument, he rechecked the linesfrom 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 correctwith 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 thecross lines met.
Dowst took a spike from his belt and made an X in the metal ground.
"All set," Rip announced. "You four men can move now. Let's have thecutting equipment over here, Koa."
The Planeteers were all waiting for instructions now. In a few moments theequipment 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 fororders. "We need a hole six feet across and twenty feet deep," Rip toldhim. "Go to it."
"How about direction, sir?" Kemp asked.
"Straight down. We'll take a bearing on an overhead star when you're in afew feet."
Dowst inscribed a circle around the X he had made and stood back. Kemppushed the striker button and the torch flared. "Watch your eyes," hewarned. The Planeteers reached for belt controls and turned the rheostatsthat darkened the clear bubbles electronically. Kemp adjusted his flameuntil it was blue-white, a knife of fire brighter by far than the sun.
Koa stepped behind Kemp and leaned against his back, because the flame ofthe torch was like an exhaust, driving Kemp backward. Kemp bent do
wn andthe 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 almostabsolute zero to many thousands of degrees.
When the circle was completed, Kemp adjusted his torch again and the flamelengthened. He moved inside the circle and cut at an angle toward theperimeter. His control was quick and certain. In a moment he stood asideand Koa lifted out a perfect ring of thorium. It varied from a knife edgeon the inner side to 18 inches thick on the outer edge.
In the middle of the circle there was now a cone of metal. Kemp cut aroundit, the torch angling toward the center. A piece shaped like two cones setbase to base came free. Since the metal cooled in the bitter chill ofspace almost as fast as Kemp could cut it, there was no heat to worryabout.
Alternately cutting from the outside and the center of the hole, Kempworked his way downward until his head was below ground level. Rip calleda halt. Kemp gave a little jump and floated straight upward. Koa caughthim and swung him to one side. Rip stepped into the hole and Santos gavehim 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 an overhead guide wasstraight up.
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 andconnect up the ten kiloton bomb. Nunez, bring it here while Dominico getswhat he needs."
Kemp was burning his way into the asteroid at a good rate. Every fewmoments 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 theasteroid. 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 fordirect communication. He didn't want the others to hear what he had tosay. 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 calculationshad showed that the metal would do little more than compress, except whereit melted from the terrific heat of the bomb. That would be only in andaround the shaft. He was sure the men at Terra base had figured it outbefore they decided that A-bombs would be necessary to throw the asteroidinto a new orbit. He wasn't worried. Cracks in the asteroid would bedangerous, but he hadn't seen any.
"This rock will take more nuclear blasts than we have," he assured Koa. Heturned his communicator back on and went to the edge of the hole for alook at Kemp's progress. He was far down, now. Pederson was holding oneend of a measuring tape. The other end was fastened to Kemp's shoulderstrap.
The Swedish corporal showed Rip that he had only about eight feet of tapeleft. Kemp was almost down. Rip called, "Kemp. When you reach bottom, cuttoward 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 atimer 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 oneline. We'll be taking off in a few minutes."
"Right, sir." Koa glided toward the landing boat, which was out of sightover the horizon.
It was nearly time. Rip had a moment's misgiving. Had his figures or hissightings been off? His red hair prickled at the thought. But the ship'scomputer 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 holehimself, carrying his torch.
Rip inspected the hole, saw with satisfaction it was in almost perfectalignment, and ordered the bomb placed. He bent over the edge of the holeand watched Trudeau pay out wire while Dominico pushed the bomb to thebottom. The Italian made a last minute check, then called to Rip. "Ready,sir."
He dropped into the hole and inspected the connections himself, thenpersonally pulled the safety lever. The bomb was armed. When the timeracted, it would go off.
Back at ground level, he turned up his communicator. "Koa, is everythingready at the boat?"
"Ready, sir."
The Planeteers had already carried away the torch and its fuel and oxygensupplies. The area was clear of pieces of thorium.
Rip announced, "We're setting the explosion for ten minutes." He leanedover the timer, which rested near the lip of the hole, took the dialcontrol in his glove and turned it to position ten. He held it long enoughto glance at his chronometer and say, "Starting now!" Then he let it go.
Wasting no time, but not hurrying, he and Dominico returned to the landingboat. The Planeteers were already aboard, except for Koa, who stood by tocast off the remaining tie line. Rip stepped inside and counted the men.All present. He ordered, "Cast off." As Koa did so and stepped aboard, headded, "Pilot, take off. Straight up."
The landing boat rose from the asteroid. Rip counted the men again, justto be sure. The boat seemed a little crowded, but that was because therear compartment took up quite a bit of room.
Rip watched his chronometer. They had plenty of time. When the boatreached a point about ten miles above the asteroid, he ordered, "Sterntube." The boat moved at an angle. He let it go until a sight at the starsshowed they were about in the right position, 90 degrees from the line ofblast and where they would be behind the asteroid as it moved toward thenew course.
He looked at his chronometer again. "Two minutes. Line up at the side ifyou want to watch, but darken your helmets to full protection. This thingwill light up like nothing you've ever seen before."
It was a good thing space cruisers depended on their radar and not onsight, he thought. Usually spacemen opened up visual ports only whenlanding or taking a star sight for an astro-plot. The clear plastic of thedomes had to be shielded from chance meteors. Besides, radar screens weremore dependable than eyes, even though they could pick up only solidobjects. If the Consops cruiser happened to be searching visually, itwould see the blast. But the chance had to be taken. It wasn't really muchof a chance.
"One minute," he said. He faced the asteroid, then darkened his helmet,counting to himself.
The minute ticked off slowly, though his count was a little fast. When hereached five, brilliant, incandescent light lit up the interior of theboat. Rip saw it even though his helmet was dark. The light faded slowly,and he put his helmet back on full transparent.
A mighty column of fire now reached out from the asteroid into space. Ripheld his breath until he saw that the little planet was sheering off itscourse under the great blast. Then he sighed with relief. All was well sofar.
Someone muttered, "By Gemini! I'm glad we're out here instead of downthere!"
The column of fire lengthened, thinned out, grew fainter until there wasonly a glow behind the asteroid. Rip took his astrogation instruments andmade a number of sights. They looked good. The first blast had workedabout as predicted, although he wouldn't be able to tell how muchcorrection was needed until he had taken star sights over a period of fiveor six days.
"Let's go home," he ordered.
Back on the asteroid, a pit that glowed with radioactivity marked the siteof the first blast. Rip ordered it covered as much as possible with thethorium that had been taken from the hole. While the men worked, heplotted the lines for the second blast, found the spot, and put Kemp backto work on a new hole.
Two hours later the second blast threw fire into space. In another threehours, with the asteroid now speeding on its new course, Rip set off theexplosion that blasted straight back and gave extra speed.
Three radioactive craters marked the asteroid. Rip checked the radiationlevel and didn't like it a bit. He decided to set up the landing boat andtheir supplies as far away from the craters as possible, which was on thesun side. They could move to the dark side as they approached the orbit ofearth. By then the radioactivity fro
m the blasts would have died downconsiderably.
He was selecting the location for a base when Dowst suddenly called."Lieutenant! Lieutenant Foster!"
There was urgency in the Planeteer's voice. "What is it, Dowst?"
"Sir, take a look, about two degrees south of Rigel!"
Rip found the constellation Orion and looked at bright Rigel. For a momenthe saw nothing; then, south of the star, he saw a thin, orange line.
Nuclear drive cruisers didn't have exhausts of that color, and there wasonly one rocket-drive ship around, so far as they knew.
Rip said softly, "Let's get our house in order, gang. Looks like we'regoing to get a visit from our friends the Connies!"