Space Tug (Sequel to Space Platform)
Public Domain
Chapter 11
The others got the space 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 Moonship had taken off for the Moon on the other side of the Platform’s orbit, 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 space tug was now on the reverse side of the Platform’s orbit. 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 space 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 mass. He stopped it. They would.
“Everything’s loaded?” he demanded. “Okay! Space suits! All set? Let’s get out of this lock and start blasting!”
He drove them into the space 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 space 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 ship 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 space tug’s present motion, it was logical to dive toward it. The ship would plunge toward Earth, and Earth’s gravity would help its rockets in the attainment of frenzied speed. But the tug still possessed its orbital 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 space 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 ship 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 space 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 ship’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 ship 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 Space 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 ship 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 space tug could take rockets from its cargo and set them outside its hull for firing. No other ship could.
Haney and the Chief came back. There was dead silence in the ship, save for a small, tinny voice in Joe’s headphones.
“We’ll pass 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.”
Nobody 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 flashing 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 Moonship 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 Moonship 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 space tug came cautiously close to the Moonship. Mike climbed out on the outside of the tug’s hull, with the Chief also in space 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 Moonship’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 passengers 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 ships 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 battleship 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 space tug had a line made fast. In half an hour, the two space craft were bound firmly together, but far enough apart for the rocket blasts to dissipate before they reached the Moonship. Mike returned to the tug. A pair of the big Mark Twenty rockets burned frenziedly in emptiness.
The Moonship 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 space 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 shore. 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 ships. It grew slowly, slowly larger. The word from Earth was that considering the rockets still available in the space tug, and those that should have been fired but weren’t on the Moonship, there must be no more blasts just yet. The two ships must pass 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 Moonship itself must fire its remaining fuel-store. With luck, it was a toss-up. Safety or a smash.