The Boomerang Circuit

CHAPTER VII One Chance in a Million

IN SPITE of his pessimism, Kim settled I down to the -fine calculations required for a voyage to a blue-white dwarf star not readily distinguished from others. Most inhabited planets, of course, circled sol-type suns. Light much different from that in which the race had developed was apt to have produced vegetation inimical to humanity, and useful vegetation did not thrive. And of course sol-type stars are most readily spotted by space navigators. As he checked his course with star-charts, Dona spoke softly.

"Thanks, Kim."

"For what?"

"For not wanting to put me in safety when you're going to do something dangerous. I wouldn't let you, but thanks for not trying."

"Mmmmh!" said Kim. "You're too useful."

He lined up his course and pressed the transmitter-drive stud on the control-panel. Space danced a momentary saraband,—and there was a blue-white dwarf two hundred million miles away, showing barely a planet-sized disk, but pouring out a pitiless white glare that hurt the eyes.

"That's it," said Kim. "That's the sun Alis. There should be four planets, but we're looking for Number One. It goes out beyond Two at aphelion, so we have to check the orbit—if we can find it—before we can be sure. No—we should be able to tell by the rotation. Very slow."

"And what are you going to do with it?" demanded Dona.

There were bright spots in emptiness which the electron telescope instantly declared to be planets. Kim set up cameras for pictures.

"Alis One is the only really uninhabitable planet in the galaxy that's inhabited," he observed painstakingly. "It belongs to Pharos Three. I understand it's the personal property of the king. It has no atmosphere in spite of an extremely high specific gravity and a reasonable mass. But the plutonium mines have been worked for five thousand years."

"Plutonium mines with that half-life?" Dona said skeptically. "You must be joking!"

"No," said Kim. "It's a very heavy planet, loaded with uranium and stuff from bismuth on out. It has an extremely eccentric orbit. As I told you, at aphelion it's beyond the orbit of Pharos Two. At perihelion, when it's nearest to its sun, it just barely misses Roche's Limit—the limit of nearness a satellite can come to its primary without being torn apart by tidal strains. And at its nearest to its sun, it's bombarded with everything a sun can fling out into space from its millions of tons of disintegrating atoms. Alpha rays, beta rays, gamma particles, neutrons, and everything else pour onto its surface as if it were being bombarded by a cyclotron with a beam the size of a planet's surface. You see what happens?"

Dona looked startled.

"But Kim, every particle of the whole surface would become terrifically radioactive. It would kill a man to land on it!"

"According to my merchant-prince friend on Spicus Five, it did kill the first men to set foot on it. But the point is that its heavy elements have been bombarded, and most of its uranium has gone on over to plutonium and americium and curium. In ancient days, when it went out on the long sweep away from its sun, it cooled off enough for men to land on it at its farthest-out point. With shielded space-suits they were able to mine its substance for four to five months before heat and rising induced radio-activity drove them off again. Then they'd wait for it to cool off once more on its next trip around.

"They went to it with space-ships, and the last space-line in the First Galaxy ran plutonium and americium and the other radioactives to a matter-transmitter from which they could be distributed all over the galaxy. But it wasn't very efficient. They could only mine for four or five months every four years. All their equipment was melted and ruined when they were able to land again. A few hundred years ago, however, they solved the problem."

DONA stared out the vision-ports. Then were two planets which might be tilt one in question. But there were only three an sight.

“How did they solve it?" Dona asked.

“Somebody invented a shield," said Kim as drily as before. "It was a force-field. It has the property of a magnetic field on a conductor with a current in it, except that at acts on mass as such. A current-carrying conductor in a magnetic field tends to move at right angles both to the current and the field. This force-field acts as if mass were an electric charge.

"Anything having mass, entering the field, tries to move sidewise. The faster it moves, the stronger the sidewise impulse. Neutrons, gamma particles, met rays and even electrons have mass. So has light. Everything moving that hits the shielding field moves sidewise to its original course. Radiation from the sun isn't reflected. It's deflected, at right angles.

“So, with the shield up men can stay on the planet when it is less than three diameters from its sun. No heat reaches it. No neutrons. No radiations at all. It doesn't heat up. And that's the answer. For three months in every four-year revolution, they have to keep the shield up all the time. For three months more they keep it up intermittently, flashing it on for fractions of a second at a time, just enough to temper the amount of heat they get.

They live on great platforms of uranium glass, domed in. When they go out mining they wear shielded space-suits and work in shielded machines. The whole trick was worked out about five hundred years ago, they say, and the last space-line went out of existence, because they could use a matter-transmitter for all but six of our months of that planet's year."

"And did you find out how it's done?" asked Dona.

"Hardly," said Kim. "The planet belongs to the king of Pharos Three. Even five hundred years ago the governments of all the planets were quite tight corporations. Naturally Pharos wouldn't let the secret get out. There are other planets so close to their primaries that they're radioactive. If the secret were to be disclosed there'd be competition. There'd be other plutonium mines in operation. So he's managed to keep it to himself. But we've got to find out the trick." There was silence. Kim began to check over the pictures the cameras had taken and developed. He shook his head. Then he stared at a photograph which showed the blue-white dwarf itself. His face looked suddenly very drawn and tired.

"Kim," said Dona presently. "It's stupid of me, but I don't see how you're going to learn the secret."

Kim put the picture on the enlarger, for examination in a greater size.

"They made the shield to keep things out," he said wearily. "Radiation, charged particles, neutrons—everything. The planet simply can't be reached, not even by matter-transmitters, when the shield is up. But by the same token nothing can leave the planet either. It can't even be spotted from space, because the light of the sun isn't reflected. It's deflected to a right-angled course. You might pick it up if it formed a right-angled triangle with you and the sun, or you might spot it in transit across the sun's disk. But that's all."

"Yes."

"The shield was a special job," said Kim. "For a special purpose. It was not a weapon. But there were all those planets that could be grabbed if only Ades were knocked out. So why shouldn't King Pharos sneak a force-field generator on to Ades? When the field went on, Ades would be invisible and unreachable from outside. And the outside would be unreachable from it. Space-ships couldn't get through the field. Matter-transmitters couldn't operate through it. If a few technicians were sneaked to Ades as supposed exiles and promised adequate reward, don't you think they'd hide out somewhere and turn on that field, and leave it on until the folk on Ades had starved or gone mad?"

HORRIFIED, Dona stared at him. She went pale. "Oh—horrible! The sky would be black—always! Never a glimmer of light. No stars. No moons. No sun. The plants would die and rot, and the people would grow bleached and pale, and finally they'd starve."

"All but the little gang hidden away in a well-provisioned hideout," said Kim grimly. "I think that's what's happened to Ades, or is happening. And this is the solar system where the little trick was worked out. I'd hoped simply to raid the generator and find out how it worked, which would be dangerous enough. Look!"

He pointed to the projected image of the sun. There was a tiny dot against its surface. It was almost, it seemed, bathed in the tentacular arms of flaming gases flung up from the sun's surface.

"There's the planet," said Kim. "At its closest to the sun! With the shield up, so that nothing can reach its surface. Nothing! And that includes space-ships such as this. And at that distance, Dona, the hard radiation from the sun would go right through the Starshine and kill us in seconds before we could get within millions of miles of the planet. If there's any place in the universe that's unapproachable, there it is. It may be anything up to three months before the shield goes down even for fractions of a second at a time. And my guess is that the people on Ades won't last that long. They've had days in which to grow hopeless already. Want to gamble?"

Dona looked at him. He regarded her steadily.

"Whatever you say, Kim."

"Sixteen million lives on Ades, besides other aspects of the situation," said Kim. "The odds against us are probably about the same, sixteen million to one. That makes it a fair bet. We'll try."

He got up and began to tinker with the radiation-operated relay which turned off the transmitter-drive. Presently he looked up.

"I'm glad I married you, Dona," he said gruffly.

As the Starshine moved closer in, the feeling in the control-room grew tense. The little ship had advanced to within twenty millions of miles of the blue-white sun, and even at that distance there was a detectable X-ray intensity.

Kim had turned on a Geiger counter, and it was silent simply because there was no measurable interval between its discharges. A neutron detector showed an indication very close to the danger mark. But Kim had the Starshine's nose pointed to the intolerably glaring sun.

The electron telescope showed the sun's surface filling all its field, and because the illumination had been turned so low, raging sun-storms could be seen on the star's disk. Against it, the black silhouette of the planet was clear. It was small. Kim estimated its diameter at no more than six thousand miles. The Starshine's gyros hummed softly and the field of the telescope swayed until the planet was centered exactly.

There was a little sweat on Kim's forehead.

"I—don't mind taking the chance myself, Dona," he said, dry-throated. "But I hate to think of you. . . If we miss, we'll flash into the sun."

"And never know it," said Dona, smiling. "It'll be all over in the skillionth of a second—if we miss. But we won't."

"We're aiming for the disk of the planet," t he reminded her. "We have to go in on transmitter-speed to cut the time of our exposure to hard radiation. That speed will make the time of exposure effectively zero. But we have to move at a huge multiple of the speed of light, and we have to stop short of that planet. It may not be possible!"

"Do you want me to press the button, Kim?" Dona said softly.

He took a deep breath. "I'll do it. Thanks, Dona."

He put his finger on the stud that would throw the ship into transmitter-drive, aimed straight at the disk of planet against the inferno of sun beyond. There was nothing more certain than that to miss the planet would fling them instantly into the sun. And there was nothing more absurd than to expect to come out of transmitter-drive within any given number of millions of miles, much less within a few thousands. But—

Kim pressed the stud.

Instantly there was blackness before them. A monstrous, absolute blackness filled half the firmament. It was the force-field-shielded planet, blotting out its sun and half the stars of the galaxy. Kim had made a bull's-eye on a target relatively the size of a dinnerplate at eleven hundred yards. More than that, he had stopped short of his target, equivalent to stopping a bullet three inches short of that plate.

He said in a queer voice:

"The—relay worked—even backward, Dona."