Asteroid now within protection reach of Mercury and Terra bases. Your escort no longer required. Proceed immediately Titan, take on cargo and personnel.
Asteroid now within protection reach of Mercury and Terra bases. Your escort no longer required. Proceed immediately Titan, take on cargo and personnel.
The commander sighed. "Looks like I'll never get to Earth long enough to see my family."
Rip sympathized. "Tough, sir. Perhaps the cargo from Titan will be scheduled for Terra."
"That's what I hope," O'Brine agreed. "Well, here's where we part. Is there anything you need?"
Rip made a mental check on supplies. He had more than enough. "The only thing we need is a long-range communicator, sir. We'll need one to contact the planet bases."
"I'll see that you get one." The Irishman thrust out his hand. "Stay out of high vack, Foster. Too bad you didn't join us instead of the Planeteers. I might have made a decent officer out of you."
Rip grinned. "That's a real compliment, sir. I might return it by saying that you have the makings of a Planeteer officer yourself."
O'Brine chuckled. "All right. Let's declare a truce, Planeteer. We'll meet again. Space isn't very big."
A short time later Rip stood in front of his asteroid base and watched the great cruiser drive into space. A short distance away a snapper-boat was lashed to the landing boat. O'Brine had left it, with a word of warning.
"These Connies are plenty smart. I don't like leaving you unprotected, even within reach of Mercury and Terra, but orders are orders. Keep the snapper-boat, and you'll at least be able to put up a fight if you bump into trouble."
The asteroid sped on its lonely way for two days, and then a cruiser came out of space, its nuclear drive glowing. The Planeteers manned the rocket launcher, and Rip and Santos stood by the snapper-boat, just in case, but the cruiser was theSagittarius, out of Mercury.
Capt. Go Sian-tek, a Chinese Planeteer officer, arrived in one of the cruiser's boats with three enlisted men.
Captain Go greeted Rip and his men, then handed over a plastic stylus plate ordering Rip to deliver six cubic meters of thorium for use on Mercury. While Koa supervised the cutting of the block, Rip and the captain chatted.
The Mercurian Planeteer base was in the twilight zone, but the Planeteers always worked on the sun side, wearing special alloy suits to mine the precious nuclite that only the hot planet provided.
At some time during its first years, Mercury had been so close to the sun that its temperature was driven high enough to permit a subatomic thermonuclear reaction. The reaction had shorn some elements of their electrons and left a thin coating of material composed almost entirely of neutrons. The nuclite was incredibly dense. It could be handled only in low gravity because of its weight. But nothing else provided the shielding against radiation and meteors half so well, and it was in great demand.
"Things aren't so bad," Go told Rip. "The base is comfortable, and we only work a two-hour shift out of each ten. We've had a plague of silly dillies recently. They got into one man's suit while we were working, but mostly they're just a nuisance."
Rip had heard of the creatures. They were like Earth armadillos, except that they were silicon animals and not carbon like those of Earth. They were drawn to oxygen like iron to a magnet, and their diamond-hard tongues, used for drilling rock in order to get the minerals on which they lived, could drive right through a space suit. Or, if these animals worked undetected for a while, they could drill through the shell of a space station.
Scralabus primuswas the scientific name of the creature, but the fact that it looked like a silicon armadillo had given it the popular name of "silly dilly." Apart from its desire for oxygen, it was harmless.
Koa reported, "Sir, the block of thorium is ready. We've hung it on a line behind the landing-boat. The blast won't hurt it, and it's too big to get inside the boat."
"Fine, Koa. Well, Captain, that does it."
The Mercurian Planeteers got into their craft and blasted off, trailing the block of thorium in their exhaust. Rip watched the cruiser take the craft and thorium aboard, then drive toward Mercury, brilliant sunlight reflecting from its sleek sides. The planet was only a short distance away by spaceship. It was the largest thing in space, except for the sun, as seen from the asteroid.
Past the orbit of Mercury, the sun side of the asteroid grew dangerously hot for men in space suits. Rip and the Planeteers stayed in the bitter cold of the dark side, which ceased to be entirely dark. The temperature rose somewhat. They were close enough to the sun that the prominences, great flaming tongues of hydrogen that sped many thousands of miles into space, gave them light and enough heat to register on Rip's instruments.
Mercury was left far behind, and Earth could not be seen because of the sun. There was nothing to do now but ride out the rest of the trip as comfortably as possible, until it was time to throw the asteroid into a series of ever-tightening elliptical orbits around Earth, known as braking ellipses. The method would use Earth's gravity to slow them down to the proper speed. A single atomic bomb and a half dozen tubes of rocket fuel remained.
Then, as Rip was enjoying the comfort of air during his off-watch hour in the boat compartment, Koa beat an alarm on the door.
Rip and the Planeteers got into suits and opened up.
"It's Terra base calling on the communicator, sir," Koa reported. "Urgent message, they said, and they want to talk to you personally."
Rip hurried to the cave. The communicator indicator light was glowing bright red. He plugged in his helmet circuit and said, "This is Lieutenant Foster. Go ahead."
A voice crackled across space from Earth. "This is Terra base. Foster, a Consops cruiser has apparently been hiding behind the sun waiting for you. Our screens just picked it up, heading your way. We've sent orders to theSagittariuson Mercury to give you cover, and theAquilahas taken off from here. But get this, Foster. The Consops cruiser will reach you first. You have about one hour. Do you understand?"
Rip understood all right. He understood too well. "Got you," he said shortly. "Now what?"
The communicator buzzed. "Take any appropriate action. You're on your own. Sorry. Sending the cruisers is all we can do. We'll stand by for word from you. If you think of any way we can help, let us know."
Rip asked, "How long before the cruisers arrive?"
"You're too close to us for them to move fast. They'll have to use time accelerating and decelerating. TheSagittariusshould arrive in something less than two hours and theAquilaa few minutes later."
The communicator paused, then continued. "One thing more, Foster. The Connies know how badly we want that asteroid, but they also know we don't want it enough to start a war. Got that?"
"Got it," Rip stated wryly. "I got it good. Thanks for the warning, Terra base. Foster off."
"Terra base off. Stay out of high vack."
Fine advice, if it could be taken. Rip stared up at the brilliant stars, thinking fast. The Connie would have almost an hour's lead on the space-patrol cruisers. In that hour, if the Connie were willing to pay the price in blasted snapper-boats, Consops would have the asteroid. And Terra base had made it clear that the space patrol would not try to blast the Connie cruiser, because that would mean war.
Added together, the facts said just one thing: They had one hour in which to think of some way to hold off the Connies for an additional hour.
The Planeteers were clustered around him. Rip asked grimly, "Any of you ever study the ancient art of magic?"
The Planeteers remained silent and tense.
"Magic is what we need," Rip told them. "We have to make the whole asteroid disappear, or else we have to conjure up a space cruiser out of the thorium. Otherwise, we have barely an hour till we're either prisoners or dead!"
Sergeant major Koa asked thoughtfully, "Sir, would it do the Connie much good to launch boats this close to the sun? They'd have to use too much fuel just keeping position."
"You could be right," Rip said slowly. Koa had a point! To counter gravitational attraction took velocity, which meant consumption of fuel. Maneuvering boats meant rapid velocity changes. Against the sun's terrific gravity at this distance, it also meant maximum thrust and maximum fuel flow most of the time. The asteroid, in a planned orbit with the correct velocity, was safe enough, and the Connie cruiser would simply match the asteroid's orbit. But boats, which had to maneuver, were another matter.
Rip figured quickly. In accordance with Newton's Law, gravitational attraction increased rapidly on approaching a body. If he could put the asteroid even closer to the sun, the boat problem would become worse, until even a small velocity change in the wrong direction could leave a boat in the terrible position of not having enough thrust for a long enough time to keep from being drawn into the sun.
But to change the asteroid's orbit was dangerous! It meant losing just enough velocity to be drawn closer to the sun, and then picking up a much higher velocity to get free again!
Rip got his instruments and pulled out a special slide rule designed for use in space. He had Koa stand by with stylus and computation board and take down his figures.
He recalculated the safety factor he had used when deciding how close to the sun to put the asteroid, then took quick star sights to determine their exact position. They were within a few miles of perihelion, the point at which they would be closest to Sol.
Rip tapped gloved fingers on his helmet absently. If they could blast out of the orbit and drive into the sun.... He estimated the result. A few miles per second of less speed would let them be pulled so far within the sun's field of gravity that, within an hour or so, small boats would venture into space only at their peril.
He reviewed the equipment. They had tubes of rocket fuel, but the tubes wouldn't give the powerful thrust needed for this job. They had one atomic bomb. One wasn't enough. Not only must they drive toward the sun, but also they must keep reserve power to blast free again. If only they had a pair of nuclear charges!
He called his Planeteers together and outlined the problem. Perhaps one of them would have an idea. But no useful suggestions were forth-coming—until Dominico spoke up. "Sir, why don't we make two bombs from one?"
"I wish we could," Rip said. "Do you know how?"
"No, Lieutenant. If we had parts, I could put bombs together. I can take them apart, but I don't know how to make two out of one." The Italian Planeteer looked accusingly at Rip. "I thought maybe you knew, sir."
Rip grunted. If they had parts, he could assemble nuclear bombs, too. Part of his physics training had been concerned with fission and its various applications. But no one had taught him how to make two bombs out of one.
The theory behind this particular bomb design was simple. Two or more correctly sized pieces of plutonium or uranium isotope, when brought together, formed what was known as a critical mass, which would fission. The fissioning released energy and produced the explosion.
But there was a wide gap between theory and practice. A nuclear bomb was actually pretty complicated. It had to be complicated to keep the pieces of the fissionable material apart until a chemical explosion drove them together fast and hard enough to create a fission explosion. If the pieces weren't brought together rapidly enough, the mass would fission in a slow chain reaction with no explosion.
Rip was trained in scientific analysis. He tackled the problem logically, considering the design of a nuclear bomb and the reasons for it.
Atomic bombs had to be carried. That meant an outer casing was necessary. The casing had a lot to do with the design. Suppose no casing were required? What would be needed?
He took the stylus and computation board from Koa and jotted down the parts required. First, two or more pieces of plutonium large enough to form a critical mass. Second, a neutron source—the type of radioactivity that produced neutrons—to accelerate the reaction. Third, some kind of neutron reflector. And fourth, explosive to drive the pieces together.
Did they have all those items? He checked them off. Their single five KT bomb contained at least enough plutonium for two critical masses, if brought together inside a good neutron reflector. Each mass should give about a two kiloton explosion. And they did have a good neutron reflector—nuclite. There wasn't anything better.
"What have we got for a neutron source?" he asked aloud. He was really asking himself, but he got a quick answer from Koa.
"Sir, some of the stuff left in the craters from the other explosions gives off neutrons."
"You're right," Rip agreed instantly. A small piece from one of the craters, when combined with half of the neutron source in the bomb, should be enough. As for the explosive, they had exploding heads on their attack rockets.
In other words, he had what he needed—except for a method of putting all the pieces together to create a bomb.
If only they had a tube of some sort that would withstand the chemical explosion—the one that brought the critical mass together!
He told the Planeteers what he had been thinking, then asked, "Any ideas for a tube?"
"How about a tube from the snapper-boat?" Santos suggested.
Rip shook his head. "Not strong enough. They're designed to withstand the slow push of rocket fuel, not the fast rap of an explosion. When I say slow, I mean slow-burning when compared with explosive. Any more ideas?"
Kemp, the expert torchman, said, "Sir, I can burn you a tube into the asteroid."
Rip grabbed the Planeteer so hard they both floated upward. "Kemp, that's wonderful! That's it!" The details took form in his mind even as he called orders. "Dominico, tear down that bomb. Santos, remove two heads from your rockets and wire them to explode on electrical impulse. Kemp, we'll want the tube just a fraction of an inch wider than a rocket head. Get your torch ready."
He took the stylus and began calculating. He talked as he worked, telling the Planeteers exactly what they were up against. "I'm figuring out where to put the charge so it will do the most good, but my data isn't complete. If our homemade bomb goes off, I don't know exactly how much power it will give. If it gives too much, we'll be driven so close to the sun we'll never get free of its gravity."
Bradshaw, the English Planeteer, said mildly, "Don't worry, Lieutenant. If it isn't the solar frying pan, it's Connie fire."
A chorus of agreement came from the other Planeteers. "What a crew!" Rip thought. "What a great gang of space pirates!"
He finished his calculations and found the exact place where Kemp would cut. A few feet away from the spot was a thick pyramid of thorium. That would do, and they could cut into it horizontally instead of drilling straight down. He pointed to it. "Let's have a hole straight in for six feet. And keep it straight, Kemp. Allow enough room for a lining of nuclite. Koa, cut a sheet of nuclite to size."
Kemp's torch already was slicing into the metal. Rip asked, "Can you weld with that thing, Kemp?"
"Just show me what you want, sir."
"Good." Rip motioned to Trudeau. "Frenchy, we'll need a strong rod at least eight feet long."
The French Planeteer hurried off. Rip consulted his chronometer. Less than ten minutes had passed since the call from Terra base.
He went over his plan again. It had to work! If it didn't, asteroid and Planeteers would end up as subatomic particles in the sun's photosphere, because he had calculated his blast to drive the asteroid past the limit of safety. It was the only way he could be sure of putting them beyond danger from Connie landing boats or snapper-boats. The Connie would have only one chance—to bring his cruiser down.
If he tried that, Rip thought grimly, he would get a surprise. The second nuclear charge would be set, ready to be fired. The Connie cruiser was so big that no matter how it pulled up to the asteroid, some part of it would be close enough to the charge to be blown into space dust. No cruiser could survive an atomic explosion within five hundred yards, and the Connie would have to get closer to the nuclear charge than that.
Dominico reported that the bomb had been dismantled. Rip went to it and examined the raw plutonium, being careful to keep the pieces widely separated.
This particular bomb design used five pieces of plutonium which were driven together to form a ball. Rip made a quick estimate. Two were enough to form a critical mass. He would use two to blast into the sun and three to blast out again. He would need the extra kick.
There was only one trouble. The pieces were wedge shaped. They would have to be mounted in thorium in order to keep them rigid. Only Kemp could do that. They had no cutting tool but the torch.
Santos appeared, carrying a rocket head under each arm. They had wires wound around them, ready to be attached to an electrical source.
Rip hurried back to where Kemp was at work. The private was using a cutting nozzle that threw an almost invisible flame five feet long. In air, the nozzle wouldn't have worked effectively beyond two feet, but in space it cut right down to the end of the flame. Kemp had his arm inside the hole and was peering past it as he finished the cut.
"Done, sir," he said, and adjusted the flame to a spout of red fire. He thrust the torch into the hole and quickly withdrew it as pieces of thorium flew out. A stream of water hosed into the tube would have worked the same way.
Rip took a block of plutonium from Dominico and handed it to Kemp. "Cut a plug and fit this into it. Then cut a second plug for the other piece. They have to match perfectly, and you can't put them together to try out the fit. If you do, we'll have fission right here in the open."
Kemp searched and found a piece he had cut in making the tube. It was perfectly round, ideal for the purpose. He sliced off the inner side where it tapered to a cone, then, working only by eye estimate, cut out a hole in which the wedge of fission material would fit. He wasn't off by a thirty-second of an inch. Skillful application of the torch melted the thorium around the wedge and sealed it tightly.
Koa was ready with a sheet of nuclite. Trudeau arrived with a pole made by lashing two crate sticks together.
Rip gave directions as they formed a cylinder of nuclite. Kemp spot-welded it, and they pushed it into the hole.
Nunez found a small piece of material in one of the earlier craters. It would provide some neutrons to start the chain reaction. Rip added it to the front of the plutonium wedge, along with a piece of beryllium from the bomb, and Kemp welded it in place.
They put the thorium block which contained the plutonium into the hole, the plutonium facing outward. Trudeau rammed it to the bottom with his pole. The neutron source, the neutron reflector, and one piece of fissionable material were in place.
Kemp sliced another round block of thorium out of a nearby crystal and fitted the second wedge of plutonium into it. At first Rip had worried about the two pieces of plutonium making a good enough contact, but Kemp's skillful hand and precision eye removed that worry.
The torchman finished fitting the plutonium and carried the block to the tube opening. He tried it, removed a slight irregularity with his torch, then said quietly, "Finished, sir."
Rip took over. He slid the thorium-plutonium block into the tube, took a rocket head from Santos, and used it to push the block in farther. When the rocket head was about four inches inside the tube, its wires trailing out, Rip called Kemp. At his direction, the torchman sliced a thin slot up the face of the crystal. Rip fitted the wires into it and held them in place with a small wedge of thorium.
Kemp cut a plug, fitted it into the hole, and welded the seams closed. The tube was sealed. When electric current fired the rocket head, the thorium carrying the plutonium wedge would be driven forward to meet the wedge in the back. And, unless Rip had miscalculated the mass of the two pieces, they would have their nuclear blast. Rip surveyed the crystal with some anxiety. It looked right.
Dominico already had rigged the timer from the atomic bomb. He connected the wires. "Do I set it, sir?"
"Load the communicator, the extra bomb parts, the rocket launcher and rockets, the cutting equipment, my instruments, and the tubes of fuel," Rip ordered. "Leave everything else in the cave."
The Planeteers ran to obey. Rip waited until the landing boat was nearly loaded, then told Dominico to set the timer for five minutes. He wondered how they would explode the second charge, since they had only the one timer left, then forgot about it. Time enough to worry when faced with the problem.
"I'll take the snapper-boat," he stated. "Santos in the gunner's seat. Koa in charge in the landing boat. Dowst pilot. Let's show an exhaust."
He fitted himself into the tight pilot seat of the snapper-boat while Santos climbed in behind. Then, handling the controls with the skill of long practice, he lifted the tiny fighting rocket above the asteroid and waited for the landing boat. When it joined up, Rip led the way to safety. As he cut his exhaust to wait for the explosion, he sighted past the snapper-boat's nose to the asteroid.
Even though both boats had been careful to match velocity with the asteroid as closely as possible, the slight difference remaining caused them to drift sunward. Rip cut his jets in to compensate, and saw Dowst do the same.
Another few miles toward the sun, and the landing boat wouldn't have the power to get away from Sol's gravity. A few miles beyond that, even the powerful little snapper-boat would be caught.
Below, the timer reached zero. A mighty fan of fire shot into space. The asteroid shuddered from the blast, then swerved gradually, picking up speed as well as new direction.
Rip swallowed hard. Now they were committed. They would reach a new perihelion far beyond the limits of safety.Pfor perihelion andPfor peril. In this case, they were the same thing!
Back on the asteroid, the Planeteers started laying the second atomic charge. Rip selected the spot, found a nearby crystal that would serve to house the bomb, and Kemp started cutting.
The Planeteers knew what to do now, and the work went rapidly. Rip kept an eye on his chronometer. According to the message from Terra base, he had about fifteen minutes before the Consops cruiser arrived.
"We have one advantage we didn't have back in the asteroid belt," he remarked to Koa. "Back there they could have landed anywhere on the rock. Now they have to stick to the dark side. Snapper-boats could last on the sun side, but men in ordinary space suits couldn't."
"That's good," Koa agreed. "We have only one side to defend. Why don't we put the rocket launcher right in the middle of the dark side?"
"Go ahead. And have all men check their pistols and knives. We don't know what's likely to happen when that Connie flames in."
Rip walked over to the communicator and plugged his suit into the circuit. "This is the asteroid calling Terra base. Over."
"This is Terra base. Go ahead, Foster. How are you doing?"
"If you need anything cooked, send it to us," Rip replied. "We have heat enough to cook anything, including tungsten alloy." He explained briefly what action they had taken.
A new voice came on the communicator. "Foster, this is Colonel Stevens."
Rip responded swiftly, "Yes, sir!" Stevens was the top Planeteer, commanding officer of all the Special Order Squadrons.
"We've piped this circuit into every channel in the system," the colonel said. "Every Planeteer in the Squadrons is listening and rooting for you. Is there anything we can do?"
"Yes, sir," Rip replied. "Do you know if Terra base has been plotting our course this far?"
There was a brief silence, then the colonel answered, "Yes, Foster. We have a complete track from the time you started showing on the Terra screens, about halfway between the orbits of Mars and Earth."
"Did you just get our change of direction?"
"Yes. We're following you on the screens."
"Then, sir, I'd appreciate it if you'd put the calculators to work and make a time-distance plot for the next few hours. The blast we're saving to push to escape velocity is about three kilotons. Let us know the last moment when we can fire."
"You will have it within fifteen minutes. Anything else, Foster?"
"Nothing else I can think of, sir."
"Then, good luck. We'll be standing by."
"Yes, sir. Foster off."
Rip disconnected and turned up his helmet communicator, repeating the conversation to his men. Koa came and stood beside him. "Lieutenant, how do we set off this next charge?"
There was only one way. When the time came to blast, they would be too close to the sun to take to the boats. The blast had to be set off from the asteroid.
"We'll get underground as far away from the bomb as we can," Rip said. He surveyed the dark side, which was rapidly growing less dark. "I think the second crater will do. Kemp can square it off on the side toward the blast to give us a vertical wall to hide behind."
Koa looked doubtful. "Plenty of radiation left in those holes, sir."
Rip grinned mirthlessly. "Radiation is the least of our problems. I'd rather get an overdose of gamma then get blasted into space."
A yell rang in his helmet. "Here comes the Connie!"
Rip looked up, startled. The Consops cruiser passed directly overhead, about ten miles away. It was decelerating rapidly. Rip wondered why they hadn't spotted it earlier, then realized the Connie had come from the direction of the hot side.
The enemy cruiser was probably the same one that had attacked them before. He must have lain in wait for days, keeping between the sun and Terra. That way, the screens wouldn't pick him up, since very few observatories scanned the sun with regularity. To the observatories, the cruiser would have been only a tiny speck, too small to be noticed. Or, if they had noticed it, the astronomers probably decided it was just a very tiny sunspot.
The Planeteers worked with increased speed. Kemp welded the final plug into place, then hurried to the crater from which they would set off the charge. Dominico and Dowst connected wires from the rocket head to a reel of wire and rolled it toward the crater. Nunez got a hand-driven dynamo from the supplies and tested it for use in setting off the charge. Santos stood by the rocket launcher, with Pederson ready to put another rack of rockets into the device when necessary.
Rip and Koa watched the Connie cruiser. It decelerated to a stop for a brief second, then started moving again, with no jets showing.
"That's the sun pulling," Rip said exultantly.
"They'll have to keep blasting to maintain position."
The Consops commander didn't wait to trim ship against the sun's drag. His air locks opened, clearly visible to Rip and Koa because that side of the cruiser was brilliant with sunlight. Ten snapper-boats sped forth. Rip was certain now that this was the enemy cruiser they had fought off back in the asteroid belt. Two Connie snapper-boats had been destroyed in that clash, which explained why the commander was sending out only ten boats instead of a full quota of twelve.
The squadron instantly formed a V, like a strange space letter made up of globes. The sun's gravity pulled at them, dragging them off course. Rip watched as flames poured from their stern tubes. They were firing full speed ahead, but the drag of the sun distorted their line of flight into a great arc.
Rip saw the strategy instantly. The Connie commander knew the situation exactly, and he was staking everything on one great gamble, sending his snapper-boats to land on the asteroid—to crash-land if necessary.
The asteroid was so close to the sun that even the powerful fighting rockets would use most of their fuel in simply combating its gravity.
"All hands stand by to repel Connies," Rip shouted, and he drew his pistol. He looked into the magazine, saw that the clip was full, and then charged the weapon.
Santos was crouched over the rocket launcher, his space gloves working rapidly as he kept the rockets pointed at the enemy.
Rip called, "Santos, fire at will."
The Planeteers formed a skirmish line which pivoted on the launcher. Only Kemp remained at work. His torch flared, slicing through the thorium as he prepared their firing position.
The atomic charge was ready. The wires had been laid up to the rim of the crater in which Kemp worked, and the dynamo was attached.
Rip was everywhere, checking on the launcher, on Kemp, on the pistols of his men. And Santos, hunched over his illuminated sight, watched the Connie snapper-boats draw near.
"Here we go," the corporal muttered. He pressed the trigger.
The first rocket sped outward in a sweeping curve, and for a moment Rip opened his mouth to yell at Santos. The sun's gravity affected the attack rockets, too! Then he saw that the corporal had allowed for the sun's pull.
The rocket curved into the squadron of on-coming boats, and they all tried to dodge at once. Two of them met in a sideways crash, then a third staggered as its stern globe flared and exploded. Santos had scored a hit!
Rip called, "Good shooting!"
The corporal's reply was rueful. "Sir, that wasn't the one I aimed at. The sun's pull is worse than I figured."
The damaged snapper-boat instantly blasted from its nose tubes, decelerated, and went into reverse, flipping through space crabwise as it tried to regain the safety of the cruiser. The two boats that had crashed while trying to dodge were blasting in great spurts of flame, following the example of their damaged companion.
"Seven left," Rip called, and another rocket flashed on its way. He followed its trail as it curved away from the asteroid and into the squadron. Its proximity fuse detonated in the exhaust of a Connie boat, blowing the tube out of position. The boat yawed wildly, cut its stern tubes, and blasted to a stop from the bow tube. Then it, too, started backward toward the cruiser. Six left!
Flame blossomed a few yards from Rip. He was picked up bodily and flung into space, whirling end over end. Koa's voice rang in his helmet.
"Watch it! They're firing back!"
Rip tugged frantically at an air bottle in his belt. He pulled it out and used it to whirl him upright again; then its air blast drove him back to the surface of the asteroid. Sweat poured from his forehead, and the suit ventilator whined as it picked up the extra moisture. Great Cosmos! That was close!
Santos fired again, twice, in rapid succession. The Connie snapper-boats scattered as the proximity fuses produced flowers of fire among them. Two near misses, but they threw the enemy off course. Rip watched tensely as the boats fought to regain their course. He knew asteroid, cruiser, and boats were speeding toward the sun at close to fifty miles a second, and the drag was getting terrific. The Connies knew it, too.
There was an exultant yell from the Planeteers as two of the boats gave up and turned back, using full power to regain the safety of the mother ship. Four left!
Santos scored a direct hit on the nose of the nearest one, but its momentum drove it to within a few yards of the asteroid. Five space-suited figures erupted from it, holding hand propulsion units, tubes of rocket fuel used for hand combat in empty space.
The Connies lit their propulsion tubes and drove feet first for the asteroid. The Planeteers estimated where the enemy would land, and they were there waiting, with aimed handguns. The Connies had their hands over their heads, holding the propulsion tubes. They took one look at the gleaming Planeteer guns, and their hands stayed upright.
The Planeteers lashed the Connies' hands behind them with their own safety lines and, at Rip's orders, dumped all but one of them into the crater where Kemp was just finishing his cutting.
Three snapper-boats remained. Rip watched, holding tightly to the arm of the Connie he had kept at his side. The man wore the insignia of an officer.
The remaining snapper-boats were going to make it. Santos threw rockets among them and scored hits, but the boats kept coming. The Connies were too far away from the cruiser to return, and they knew it. Getting to the asteroid was their only chance.
Rip called, "Santos! Cease fire. Set the launcher for ground level. Let them land, but don't fire until I give the word."
He put his helmet against his prisoner's for direct communication. "You speak English?"
The man shouted back, "Yes."
"Good. We're going to let your friends land. As soon as they do, I want you to yell to them. Say we have assault rockets trained on them. Tell them to surrender, or they'll be killed in their tracks. Got that?"
The Connie replied, "Suppose I refuse?"
Rip put his space knife against the man's stomach. "Then we'll get them with rockets. But you won't care, because you won't know it."
The truth was that Santos couldn't hope to get them all with his rockets. They might overcome the Connies in hand-to-hand fighting, but there would be a cost to pay in Planeteer casualties. Rip hoped the Connie wouldn't call his bluff, because that's all it was. He couldn't use a space knife on an unarmed prisoner.
The Connie didn't know that. In Rip's place he would have no compunctions about using the knife, so instead of calling Rip's bluff, he agreed.
The snapper-boats blew their front tubes, decelerating, and squashed down to the asteroid in a roar of exhaust flames, sending the Planeteers running out of the way. Rip thrust harder with his space knife and yelled, "Tell them!"
The Connie officer nodded. "Turn up my communicator."
Rip turned it on full, and the Connie barked quick instructions. The exhausts died, and five men filed out of each boat, with hands held high. Rip blew a drop of perspiration from the tip of his nose. Empty space! It was a good thing Connie morale was bad. The enemy's willingness to surrender had saved them a costly fight.
The Planeteers rounded up the prisoners and secured them, while Rip took an anxious look at the communicator. It was about time he heard from Terra base.
The light was glowing. For all he knew, it might have been glowing for many minutes. He plugged into the circuit.
"This is Foster on the asteroid."
"Terra base to Foster. Listen. You will reach optimum position on the time-distance curve at twenty-three-oh-six."
"Got it. We will reach optimum position at twenty-three-oh-six." He looked at his chronometer, and his pulse stopped. It was 22:58! They had just eight minutes before the sun caught them forever, atomic blast or no!
And the Connie cruiser was still overhead, with no friendly cruisers in sight. He looked up, white-faced. Not only was the Connie still there, but its main air lock was sliding open to disclose a new danger.
In the opening, ready to launch, an assault boat waited. The assault boats were something only the Connies used. They were about four times the size of a snapper-boat, less maneuverable but more powerful. They carried twenty men and a pair of guided missiles with atomic warheads!
Rip ran for the snapper-boat, feet moving as rapidly as lack of gravity would permit. He called instructions. "Santos! Turn the launcher over to Pederson and come with me. Koa, take over. Start throwing rockets at that boat, and don't stop until you run out of ammunition."
He reached the snapper-boat and squeezed in, Santos close behind him. As he strapped himself into the seat he called, "Koa! Get this, and get it straight. At twenty-three-oh-five, fire the bomb. Fire it whether I'm back or not."
Koa replied, "Got it, sir."
That would give the Planeteers a minute's leeway. Not much of a safety margin, especially when he wasn't sure how much power the atomic charge would produce.
He plugged into the snapper-boat's communicator and called, "Ready, Santos?"
"Ready, Lieutenant."
He braced himself against acceleration and flipped the speed control to full power. The fighting rocket rammed out from the asteroid, snapping him back against the seat. He made a quick check. Gunsight on, fuel tanks almost full, propulsion tubes racked handy to his hand.
They drove toward the enemy cruiser at top speed, swerving in a great arc as the sun pulled at them. The enemy's big boat was out of the ship, its jets firing.
Rip leaned over his illuminated gunsight. The boat showed up clearly, the rings of the sight framing it. He estimated distance and the pull of the sun, then squeezed the trigger on the speed control handle. The cannon up in the nose spat fire. He watched tensely and saw the charge explode on the hull of the Connie cruiser. He had underestimated the sun's drag. He compensated and tried again.
He missed. Now that he was closer and the charge had less distance to travel, he had overestimated the sun's effect. He gritted his teeth. The next shot would be at close range.
The fighting rocket closed space, and the landing boat loomed large in the sight. He fired again, and the shot blew metal loose from the top of the boat's hull. A hit, but not good enough. He leaned over the sight to fire again, but before he had sighted, an explosion blew the assault boat completely around.
Koa and Pederson had scored a hit from the asteroid!
The big boat fired its side jets and spun around on course again. Flame bloomed from its side as Connie gunners tried to get the range on the snapper-boat.
Rip was within reach now. He fired at point-blank range and flashed over the boat as its front end exploded. Santos, firing from the rear, hit it again.
Rip threw the rocket into a turn that rammed him against the top of his harness. He steadied on a line with the crippled Connie craft. It was hard hit. The bow jets flickered fitfully, and the stern tubes were dead. He sighted, fired. A charge hit the boat aft and blew its stern tubes off completely.
And at the same moment, a Connie gunner got a perfect bead on the snapper-boat.
Space blew up in Rip's face. The snapper-boat slewed wildly as the Connie shot took effect. Rip worked his controls frantically, trying to straighten the rocket out more by instinct than anything else.
His eyes recovered from the blinding flash, and he gulped as he saw the raw, twisted metal where the boat's nose had been. He managed to correct the boat's twisting by using the stern tubes, but he lost full control of the ship.
For a moment panic gripped him. Without full control he couldn't get back to the asteroid! Then he forced himself to calm down. He sized up the situation. They were still underway, the stern tubes pushing, but their trajectory would take them right under the crippled Connie boat.
There was nothing he could do but pass close to the Connie. The enemy gunners would fire, but he had to take his chances. He looked down at the asteroid and saw an orange trail as Koa launched another rocket.
The shot from the asteroid ticked the bottom of the Connie boat and exploded. The Connie rolled violently. Tubes flared as the pilot fought to correct the roll. He slowed the spinning as Rip and Santos passed, just long enough for a Connie gunner to get in a final shot.
The shell struck directly under Rip. He felt himself pushed violently upward, and, at the same moment, he reacted—by hunch and not by reason. He rammed the controls full ahead, and the dying rocket cut space, curving slowly as flaming fuel spurted from the ruptured tanks.
Rip yelled, "Santos! You all right?"
"I think so. Lieutenant, we're on fire!"
"I know it. Get ready to abandon ship."
When the main mass of fuel caught, the rocket would become an inferno. Rip smashed at the escape hatch above his head, grabbed propulsion tubes from the rack, and called, "Now!"
He pulled the release on his harness, stood up on the seat, and thrust with all his leg power. He catapulted out of the burning snapper-boat into space.
Santos followed a second later, and the crippled rocket twisted wildly under the two Planeteers.
"Don't use the propulsion tubes," Rip called. "Slow down with your air bottles." He thrust the tubes into his belt, found his air bottles, and pointed two of them in the direction they had been traveling. He wanted to come to a stop, to let the wild snapper-boat get away from them.
The compressed-air bottles did the trick. He and Santos slowed down as the little jets overcame the inertia that was taking them along with the burning boat. The boat was spiraling now, burning freely. It moved away from them, its stern jets still firing weakly.
Rip took a look toward the enemy cruiser. The assault boat was no longer showing an exhaust. Instead, it was being dragged rapidly away from the Connie cruiser by the pull of the sun. At least it was hit in time to prevent launching of the atomic guided missiles. Or, he thought, perhaps the enemy had never intended using them. The principal effect, besides killing the Planeteers, would have been to drive the asteroid into the sun at an even faster rate.
The enemy assault boat was no longer a menace. Its occupants would be lucky if they succeeded in saving their own lives.
Rip wondered what the Connie cruiser commander would try now. Only one thing remained, and that was to set the cruiser down on the asteroid. If the Connie tried, he would arrive at just about the time set for releasing the nuclear charge. And that would be the end of the cruiser—and probably of the Planeteers as well.
Santos asked coolly, "Lieutenant, wouldn't you say we're in a sort of bad spot?"
Rip had been so busy sizing up the situation that he hadn't thought about his own predicament. Now he looked down and suddenly realized that he was floating free in space, a considerable distance above the asteroid, and with only small propulsion tubes for power.
He gasped, "Great space! We're in a mess, Santos."
The corporal asked, still in a calm voice, "How long will it be before we're dragged into the sun, sir?"
Rip stared. Santos had used the same tone he might have used in asking for a piece of Venusianchru. An officer couldn't be less calm, so Rip replied in a voice he hoped was casual, "I wouldn't worry, Santos. We won't know it. The heat will get through our suits long before then."
In fact, the heat should be overloading their ventilating systems right now. In a few minutes the cooling elements would break down, and that would be the end. He listened for the accelerated whine as the ventilating systems struggled under the increased heat load but heard nothing.
Funny. Had it overloaded and given out already? No, that was impossible. He would be feeling the heat on his body if that were the case.
He looked for an explanation and realized for the first time that they weren't in the sunlight at all. They were in darkness. His searching glance told him they were in the cone of shadow stretching out from behind the asteroid. The thorium rock was between them and the sun!
His lips moved soundlessly. Maj. Joe Barris had been right.In a jam, trust your hunch.He had acted instinctively, not even thinking as he used the last full power of the stern tubes to throw them into the shadow cone.
And he knew in the same moment that it could save their lives. The sun's pull would only accelerate their fall toward the asteroid. He said exultantly, "We're staying out of high vac, Santos. Light off a propulsion tube. Let's get back to the asteroid."
He pulled a tube from his belt, held it above his head, and thumbed the striker mechanism. The tube flared, pushing downward on his hand.
He held steady and plummeted feet first toward the rock.
Santos was only a few seconds behind him. Rip saw the corporal's tube flare and knew that everything was all right, at least for the moment, even though the asteroid was still a long way down.
He looked upward at the Connie cruiser and saw that it was moving. Its exhaust increased in length and deepened slightly in color as Rip watched.
Then he saw side jets flare out from the projecting control tubes and knew the ship was maneuvering. Rip realized suddenly that the cruiser was going to pick up the crippled assault boat.
He hadn't expected such a humane move, after his first meeting with the Connie cruiser when the commander had been willing to sacrifice his own men. This time, however, there was a difference, he saw. The commander would lose nothing by picking up the assault boat, and he would save a few men. Rip supposed that manpower meant something, even to Consops.
His propulsion tube reachedBrennschluss, and for a few moments he watched, checking his speed and direction. Then, before he lit off another tube, he checked his chronometer. The illuminated dial registered 23:01. They had just four minutes to get to the asteroid!
He spoke swiftly. "Waste no time in lighting off, Santos. That nuclear charge goes in four minutes!"
Rip pulled a tube from his belt, held it overhead, and triggered it. His flight through space speeded up, but he wasn't at all sure they would make it. He turned up his helmet communicator to full power and called, "Koa, can you hear me?"
The sergeant major's reply was faint in his helmet. "I hear you weakly. Do you hear me?"
"Same way," Rip replied. "Get this, Koa. Don't fail to explode that charge at twenty-three-oh-five. Can you see us?"
The reply was very slightly stronger. "I will explode the charge as ordered, Lieutenant. We can see a pair of rocket exhausts, but no boats. Is that you?"
"Yes. We're coming in on propulsion tubes."
Koa waited for a long moment, then asked, "Sir, what if you're not with us by twenty-three-oh-five?"
"You know the answer," Rip retorted crisply.
Of course Koa knew. The nuclear blast would send Rip and Santos spinning into outer space, perhaps crippled, burned, or completely irradiated. But the lives of two men couldn't delay the blast that would save the lives of eight others, not counting prisoners.
Rip estimated his speed and course and the distance to the asteroid. He was increasingly sure that they wouldn't make it, and the knowledge was like the cold of space in his stomach. It would be close but not close enough. A minute would make all the difference.
For a few heartbeats he almost called Koa and told him to wait that extra minute, to explode the nuclear charge at 23:06, at the very last second. But even Planeteer chronometers could be off by a few seconds, and he couldn't risk it. His men had to be given some leeway.
He surveyed the asteroid. The nuclear charge was on his left side, pretty close to the sun line. At least he and Santos could angle to the right, to get as far away as possible.
The edge of the asteroid's shadow was barely visible. That it was visible at all was due to the minute particles of matter and gas that surrounded the sun, even millions of miles out into space. He reduced helmet power and told Santos, "Angle to the right. Get as close to the edge of shadow as you can without being cooked."
As an afterthought, he asked, "How many tubes do you have?"
"One after this, sir. I had three."
"Save the one you have left."
Rip didn't know yet what use they would be, but it was always a good idea to have some kind of reserve.
The Connie cruiser was sliding up to the crippled assault boat. Rip took a quick look, then shifted his hands and angled toward the edge of shadow. When he was within a few feet, he reversed the direction of the tube to keep from shooting out into the sunlight. A second or two later the tube burned out.
Santos was several yards away and slightly above him. Rip saw that the Planeteer was all right and turned his attention back to the cruiser. It was close enough to the assault boat to haul it in with grappling hooks. The hooks emerged and engaged the torn metal of the boat, then drew it into the waiting port. The massive air door slid closed.
The question was, would the Connie try to set his ship down on the asteroid? Rip grinned without mirth. Now would be a fine time. His chronometer showed a minute and a half to blast time.
He took another look at his own situation. He and Santos were getting close to the asteroid, but there was still over a half mile of Earth distance to go. They would cover perhaps three-fourths of that distance before Koa fired the charge.
He had a daring idea. How long could he and Santos last in direct sunlight? The effect of the sun in the open was powerful enough to make lead run like water. Their suits could absorb some heat, and the ventilating system could take care of quite a lot. They might last as much as three minutes, with luck.
They had to take a risk with the full knowledge that the odds were against them. But if they didn't take the risk, the blast would push them outward from the asteroid—into full sunlight. The end result would be the same.
"We're not going to make it, Santos," he began.
"I know it, sir," Santos replied.
Rip thought anyone with that much coolness and sheer nerve rated some kind of special treatment. And the young corporal had shown his ability time and time again. He said, "I should have known you knew,SergeantSantos. We still have a slight chance. When I give the word, use an air bottle to push yourself into the sunlight. When I give the word again, light off your remaining tube."
"Yessir," Santos replied. "Thank you for the promotion. I hope I live to collect the extra rating."
"Same here," Rip agreed fervently. His eyes were on his chronometer, and with his free hand he took another air bottle. When the chronometer registered exactly one minute before blast time, he called, "Now!" He triggered the bottle and moved from shadow into glaring sunlight. A slight motion of the bottle turned him so his back was to the sun; then he used the remaining compressed air to push himself downward along the edge of shadow. The sun's gravity tugged at him.
He pulled the last tube from his belt and held it ready while he watched his chronometer creep around. With five seconds to go, he called to Santos and fired it. Acceleration pushed at him.
In the same moment, the nuclear charge exploded.
A mighty hand reached out and shoved Rip, sweeping him through space like a dust mote. He clutched his propulsion tube with both hands and fought to hold it steady. He swiveled his head quickly, searching for Santos, and saw the corporal a dozen rods away.
From the far horizon of the asteroid the incandescent fire of the nuclear blast stretched into space, turning from silver to orange to red as it cooled.
Rip knew they had escaped the heat and blast of the explosion, but now there was a question of how much prompt radiation they had absorbed. During the first few seconds, a nuclear blast sprayed gamma radiation and neutrons in all directions. He and Santos certainly had gotten plenty. But how much? His lower-level colorimeter had long since reached maximum red, and his high-level dosimeter could be read only on a measuring device.
Meanwhile, he had other worries. Radiation had no immediate effect. At worst, it would be a few hours before he felt any symptoms.
As he sized up his position and that of the asteroid, he let out a yell of triumph. His gamble would succeed! He had estimated that going into the direct gravity pull of the sun at the proper moment and lighting off their last tubes would put them into a landing position. The asteroid was moving rapidly, into a new orbit that would intersect the course he and Santos were on. He had planned on the asteroid's change of orbit. In a minute at most they would be back on the rock.
His propulsion tube flared out, and he released it. It would travel along with him, but his hands would be free.
Then he saw something else. The blast had started the asteroid turning!
He reacted instantly. Turning up his communicator he yelled, "Koa! The rock is spinning! Cut the prisoners loose, grab the equipment, and run for it! You'll have to keep running to stay in the shadow. If sunlight hits those fuel tanks or the rocket tubes, they'll explode!"
Koa replied tersely, "Got it. We're moving."
At least the Connie cruiser couldn't harm them now, Rip thought grimly. He looked for the cruiser and failed to find it for several seconds. It had moved. He finally saw its exhausts some distance away.
He forgot his own predicament and grinned. The Connie cruiser had moved, but not because its commander had wanted to. It had been right in the path of the nuclear blast and had been literally shoved away.
Then Rip forgot the cruiser. His suit ventilator was whining in the terrific heat, and his whole body was now bathed in perspiration. The sun was getting them. It would be only a short time until the ventilator overloaded and burned out. They had to reach the asteroid before then. The trouble was that there was nothing further he could do about it. He had only air bottles left, and their blast was so weak that the effect wouldn't speed him up much. Nevertheless, he called to Santos and directed him to use his bottles.
Santos spoke up. "Sir, we're going to make it."
In the same instant, Rip saw that they would land on the dark side. The asteroid was turning over and over. For a second he had the impression that he was looking at a turning globe of the earth, the kind used in elementary school back home. But this gray planet was scarcely bigger than the giant globe at the Space Council building on Terra.
He knew he was going to hit hard. The way to keep from being hurt was to turn the vertical energy of his arrival into motion in another direction. As he swept down to the metal surface he started running, his legs pumping wildly in space. He hit with a bone-jarring thud, lost his footing and fell sideways, both hands cradling his helmet. He got to his feet instantly and looked for Santos.
"You all right, sir?" Santos called anxiously. "I think the others are over there." He pointed.
"We'll find them," Rip said. His hip hurt like fury from smashing against the unyielding metal, and the worst part was that he couldn't rub it. The blow had been strong enough to hurt through the heavy fabric and air pressure, but his hand wasn't strong enough to compress the suit. Just the same, he tried.
And while he was trying, he found himself in direct sunlight!
He had forgotten to run. Standing still on the asteroid meant turning with it, from darkness into sunlight and back again. He yelled at Santos and legged it out of there, moving in long, gliding steps. He regained the shadow and kept going.
The first order of business was to stop the rock from turning. Otherwise they couldn't live on it.
Rip knew that they had only one means of stopping the spin. That was to use the tubes of rocket fuel left over from correcting the course. They had three tubes left, but he didn't know if that was enough to do the job.
Moving rapidly, he and Santos caught up to Koa and the Planeteers.
The Connie prisoners were pretty well bunched up, gliding along like a herd of fantastic sheep. Their shepherds were Pederson, Nunez, and Dowst. The three Planeteers had a pistol in each hand. The spares were probably those taken from prisoners.
The Planeteers were loaded down with equipment. A few Connie prisoners carried equipment, too.
Trudeau had the rocket launcher and the remaining rockets. Kemp had his torch and two tanks of oxygen. Bradshaw had tied his safety line to the squat containers of chemical fuel for the torch and was towing them behind like strange balloons. The only trouble with that system, Rip thought, was that Bradshaw could stop, but the fuel would have a tendency to keep going. Unless the Englishman was skillful, his burden would drag him off his feet.
Dominico had a tube of rocket fuel under each arm. The Italian was small, and the tubes were bulky. Each was about ten feet long and two feet in diameter. With any gravity or air resistance at all, the Italian couldn't have carried even one.
Santos took the radiation detection instruments and the case with the astrogation equipment from Koa. Rip greeted his men briefly, then took his computing board and began figuring. He knew the men were glad he and Santos had made it. But they kept their greetings short. A spinning asteroid was no place for long and sentimental speeches.
He remembered the dimensions of the asteroid and its mass. He computed its inertia, then figured out what it would take to overcome the inertia of the spin.
The mathematics would have been simpler under normal conditions, but doing them on the run, trying to watch his step at the same time, made things a little complicated. He had to hold the board under his arm, run alongside Santos while the new sergeant held the case open, select the book he wanted, open it and try to read the tables by his belt light, and then transfer the data to the board.
His ventilator had quieted down once he got into the darkness, but now it started whining slightly again because he was sweating profusely. Finally he figured out the thrust needed to stop the spin. Now all he had to do was compute how much fuel it would take.
He had figures on the amount of thrust given by the kind of rocket fuel in the tubes. He also knew how much fuel each tube contained. But the figures were not in his head. They were on reference sheets.
He collected the data on the fly, slowing down now and then to read something, until a yell from Santos or Koa warned that the sun line was creeping close. When he had all data noted on the board, he started his mathematics. He was right in the middle of a laborious equation when he stumbled over a thorium crystal. He went headlong, shooting like a rocket three feet above the ground. His board flew away at a tangent. His stylus sped out of his glove like a miniature projectile, and the slide rule clanged against his bubble.
It happened so fast that neither Koa nor Santos had time to grab him. The action had given him extra speed, and he saw with horror that he was going to crash into Trudeau. He yelled, "Frenchy! Watch out!" Then he put both hands before him to protect his helmet. His hands caught the French Planeteer between the shoulders.