Space Tug Part 25

The Moons.h.i.+p was in trouble. The sequence and timing of its rocket blasts were worked out on Earth, and checked by visual and radar observation. The computations were done by electronic brains the Moons.h.i.+p could not possibly have carried. And everything worked out. The s.h.i.+p was on course and its firings were on schedule.

But then the unexpected happened. It was an error which no machine could ever have predicted, for which statistics and computations could never have compensated. It was a _human_ error. At the signal for the final acceleration blast, the pilot of the Moons.h.i.+p had fired the wrong set of rockets.

Inexperience, stupidity, negligence, excitement--the reason didn't matter. After years of planning and working and dreaming, one human finger had made a mistake. And the mistake was fatal!

When the mistake was realized, they'd had sense enough to cut loose the still-firing rockets. But the damage had been done. The s.h.i.+p was still plunging on. It would reach the Moon. But it wouldn't land in Aristarchus crater as planned. It would crash. If every rocket remaining mounted on the hull were to be fired at the best possible instant, the Moons.h.i.+p would hit near Copernicus, and it would land with a terminal velocity of 800 feet per second--540 miles an hour.

It could even be calculated that when the Moons.h.i.+p landed, the explosion ought to be visible from Earth with a fairly good telescope. It was due to take place in thirty-two hours plus or minus a few minutes.

11

The others got the s.p.a.ce tug into the platform's lock and did things to it, in the way of loading, that its designers never intended, while Joe was calling Earth for calculations. The result was infuriating. The Moons.h.i.+p had taken off for the Moon on the other side of the Platform's...o...b..t, when it had a velocity of more than 12,000 miles an hour in the direction it wished to go. The Platform and of course the s.p.a.ce tug was now on the reverse side of the Platform's...o...b..t. And of course they now had a velocity of more than 12,000 miles per hour away from the direction in which it was urgently necessary for the s.p.a.ce tug to go.

They could wait for two hours to take off, said Earth, or waste the time and fuel they'd need to throw away to duplicate the effect of waiting.

"But we can't wait!" raged Joe. Then he snapped. "Look here! Suppose we take off from here, dive at Earth, make a near-graze, and let its gravity curve our course! Like a cometary path! Figure that! That's what we've got to do!"

He kicked off his magnetic-soled shoes and went diving down to the airlock. Over his shoulder he panted an order for the radar-duty man to relay anything from Earth down to him there. He arrived to find Haney and Mike in hot argument over whether it was possible to load on an extra ton or two of ma.s.s. He stopped it. They would.

"Everything's loaded?" he demanded. "Okay! s.p.a.ce suits! All set? Let's get out of this lock and start blasting!"

He drove them into the s.p.a.ce tug. He climbed in himself. He closed the entrance port. The plastic walls of the lock bulged out, pulled back fast, and the steering rockets jetted. The s.p.a.ce tug came out of the lock. It spun about. It aimed for Earth and monstrous bursts of rocket-trail spread out behind it. It dived.

Naturally! When a s.h.i.+p from the Platform wanted to reach Earth for atmosphere-deceleration, it was more economical to head away from it.

Now that it was the most urgent of all possible necessities to get away from Earth, in the opposite direction to the s.p.a.ce tug's present motion, it was logical to dive toward it. The s.h.i.+p would plunge toward Earth, and Earth's gravity would help its rockets in the attainment of frenzied speed. But the tug still possessed its...o...b..tal speed. So it would not actually strike the Earth, but would be carried eastward past its disk, even though aimed for Earth's mid-bulge. Yet Earth would continue to pull. As the s.p.a.ce tug skimmed past, its path would be curved by the pull of gravity. At the nearest possible approach to Earth, the tug would fire its heaviest rockets for maximum acceleration. And it would swing around Earth's atmosphere perhaps no more than 500 miles high--just barely beyond the measurable presence of air--and come out of that crazy curve a good hour ahead of the Platform for a corresponding position, and with a greater velocity than could be had in any other way. Traced on paper, the course of the tug would be a tight parabola.

The s.h.i.+p dived. And it happened that it had left the Platform and plunged deep in Earth's shadow, so that the look and feel of things was that of an utterly suicidal plunge into oblivion. There was the seeming of a vast sack of pure blackness before the nose of the s.p.a.ce tug. She started for it at four gravities acceleration, and Joe got his headphones to his ears and lay panting while he waited for the figures and information he had to have.

He got them. When the four-gravity rockets burned out, the tug's crew painstakingly adjusted the s.h.i.+p's nose to a certain position. They flung themselves back into the acceleration chairs and Joe fired a six-g blast. They came out of that, and he fired another. The three blasts gave the s.h.i.+p a downward speed of a mile and a half a second, and Earth's pull added to it steadily. The Earth itself was drawing them down most of a 4,000-mile fall, which added to the speed their rockets built up.

Down on Earth, radar-bowls wavered dizzily, hunting for them to feed them observations of position and data for their guidance. Back on the Platform, members of the crew feverishly made their own computations.

When the four in the s.p.a.ce tug were half-way to Earth, they were traveling faster than any humans had ever traveled before, relative to the Earth or the Platform itself. When they were a thousand miles from Earth, it was certain they would clear its edge. Joe proposed and received an okay to fire a salvo of Mark Tens to speed the s.h.i.+p still more. When they burned to the release-point and flashed away past the ports, the Chief and Haney panted up from their chairs and made their way aft.

"Going to reload the firing-frames," gasped the Chief.

They vanished. The s.p.a.ce tug could take rockets from its cargo and set them outside its hull for firing. No other s.h.i.+p could.

Haney and the Chief came back. There was dead silence in the s.h.i.+p, save for a small, tinny voice in Joe's headphones.

"We'll pa.s.s Earth 600 miles high," said Joe in a flat voice. "Maybe closer. I'm going to try to make it 450. We'll be smack over enemy territory, but I doubt they could hit us. We'll be hitting better than six miles a second. If we wanted to, we could spend some more rockets and hit escape velocity. But we want to stop, later. We'll ride it out."

Silence. Stillness. Speed. Out the ports to Earthward there was purest blackness. On the other side, a universe of stars. But the blackness grew and grew and grew until it neatly bisected the cosmos itself, and half of everything that was, was blackness. Half was tiny colored stars.

Then there was a sound. A faint sound. It was a moan. It was a howl. It was a shriek.... And then it was a mere thin moan again. Then it was not.

"We touched air," said Joe calmly, "at six and a quarter miles per second. Pretty thin, though. At that, we may have left a meteor-trail for the populace to admire."

n.o.body said anything at all. In a little while there was light ahead.

There was brightness. Instantly, it seemed, they were out of night and there was a streaming tumult of clouds flas.h.i.+ng past below--but they were 800 miles up now--and Joe's headphones rattled and he said:

"Now we can give a touch of course-correction, and maybe a trace of speed...."

Rockets droned and boomed and roared outside the hull. The Earth fell away and away and presently it was behind. And they were plunging on after the Moons.h.i.+p which was very, very, very far on before them.

It was actually many hours before they reached it. They couldn't afford to overtake it gradually, because they had to have time to work in after contact. But overtaking it swiftly cost extra fuel, and they hadn't too much. So they compromised, and came up behind the Moons.h.i.+p at better than 2,000 feet per second difference in speed--they approached it as fast as most rifle-bullets travel--and all creation was blotted out by the fumes of the rockets they fired for deceleration.

Then the s.p.a.ce tug came cautiously close to the Moons.h.i.+p. Mike climbed out on the outside of the tug's hull, with the Chief also in s.p.a.ce equipment, paying out Mike's safety-line. Mike leaped across two hundred yards of emptiness with light-years of gulf beneath him. His metal soles clanked on the Moons.h.i.+p's hull.

Then the vision-screen on the tug lighted up. Lieutenant Commander Brown looked out of it, quietly grim. Joe flicked on his own transmitter. He nodded.

"_Mr. Kenmore_," said Brown evenly, "_I did not contact you before because I was not certain that contact could be made. How many pa.s.sengers can you take back to the Platform?_"

Joe blinked at him.

"I haven't any idea," he said. "But I'm going to hitch on and use our rockets to land you."

"_I do not think it practicable_," said Brown calmly. "_I believe the only result of such a course will be the loss of both s.h.i.+ps with all hands. I will give you a written authorization to return on my order.

But since all my crew can't return, how many can you take? I have ten married men aboard. Six have children. Can you take six? Or all ten?_"

Then he said without a trace of emphasis, "_Of course, none of them will be officers._"

"If I tried to turn back now, I think my crew would mutiny," Joe said coldly. "I'd hate to think they wouldn't, anyhow! We're going to hook on and play this out the way it lies!"

There was a pause. Then Brown spoke again. "_Mr. Kenmore, I was hoping you'd say that. Actually--er--not to be quoted, you understand--actually, intelligent defiance has always been in the traditions of the Navy. Of course, you're not in the Navy, Kenmore, but right now it looks like the Navy is in your hands. Like a battles.h.i.+p in the hands of a tug. Good luck, Kenmore._"

Joe flicked off the screen. "You know," he said, winking at Mike, "I guess Brown isn't such a bad egg after all. Let's go!"

In minutes, the s.p.a.ce tug had a line made fast. In half an hour, the two s.p.a.ce craft were bound firmly together, but far enough apart for the rocket blasts to dissipate before they reached the Moons.h.i.+p. Mike returned to the tug. A pair of the big Mark Twenty rockets burned frenziedly in emptiness.

The Moons.h.i.+p was slowed by a fraction of its speed. The deceleration was hardly perceptible.

There were more burnings. Back on Earth there were careful measurements.

A tight beam tends to attenuate when it is thrown a hundred thousand miles. It tends to! When speech is conducted over it, the lag between comment and reply is perceptible. It's not great--just over half a second. But one notices it. That lag was used to measure the speed and distance of the two craft. The prospect didn't look too good.

The s.p.a.ce tug burned rocket after rocket after rocket. There was no effect that Joe could detect, of course. It would have been like noticing the effect of single oar-strokes in a rowboat miles from sh.o.r.e.

But the instruments on Earth found a difference. They made very, very, very careful computations. And the electronic brains did the calculations which battalions of mathematicians would have needed years to work out. The electronic calculations which could not make a mistake said--that it was a toss-up.

The Moon came slowly to float before the two linked s.h.i.+ps. It grew slowly, slowly larger. The word from Earth was that considering the rockets still available in the s.p.a.ce tug, and those that should have been fired but weren't on the Moons.h.i.+p, there must be no more blasts just yet. The two s.h.i.+ps must pa.s.s together through the neutral-point where the gravities of Earth and Moon exactly cancel out. They must fall together toward the Moon. Forty miles above the lunar surface such-and-such rockets were to be fired. At twenty miles, such-and-such others. At five miles the Moons.h.i.+p itself must fire its remaining fuel-store. With luck, it was a toss-up. Safety or a smash.

But there was a long time to wait. Joe and his crew relaxed in the s.p.a.ce tug. The Chief looked out a port and observed:

"I can see the ring-mountains now. Naked-eye stuff, too! I wonder if anybody ever saw that before!"

"Not likely," said Joe.

Mike stared out a port. Haney looked, also.