Rip Foster in Ride the Gray Planet Part 21

A short time later Rip stood in front of his asteroid base and watched the great cruiser drive into s.p.a.ce. 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 b.u.mp into trouble."

The asteroid sped on its lonely way for two days, and then a cruiser came out of s.p.a.ce, 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 the _Sagittarius_, 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 nuc.l.i.te 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 nuc.l.i.te was incredibly dense. It could be handled only in low gravity because of its weight. But nothing else provided the s.h.i.+elding 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 s.h.i.+ft 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 s.p.a.ce suit. Or, if these animals worked undetected for a while, they could drill through the sh.e.l.l of a s.p.a.ce station.

_Scralabus primus_ was 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 s.p.a.ces.h.i.+p. It was the largest thing in s.p.a.ce, 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 s.p.a.ce 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 s.p.a.ce, 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 s.p.a.ce 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 the _Sagittarius_ on Mercury to give you cover, and the _Aquila_ has 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. The _Sagittarius_ should arrive in something less than two hours and the _Aquila_ a 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 s.p.a.ce-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 s.p.a.ce 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 cl.u.s.tered 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 s.p.a.ce cruiser out of the thorium. Otherwise, we have barely an hour till we're either prisoners or dead!"

CHAPTER THIRTEEN

Peril!

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...o...b..t. 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...o...b..t 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 s.p.a.ce. 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 s.p.a.ce 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 a.s.semble 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 ma.s.s, which would fission.