The Sentinel - Arthur C. Clarke [98]
Ten years ago, then, Commander (no, Lieutenant) Falcon had invited him to a preview—a three-day drift across the northern plains of India, within sight of the Himalayas. “Perfectly safe,” he had promised. “It will get you away from the office—and will teach you what this whole thing is about.”
Webster had not been disappointed. Next to his first journey to the Moon, it had been the most memorable experience of his life. And yet, as Falcon had assured him, it had been perfectly safe, and quite uneventful.
They had taken off from Srinagar just before dawn, with the huge silver bubble of the balloon already catching the first light of the Sun. The ascent had been made in total silence; there were none of the roaring propane burners that had lifted the hot-air balloons of an earlier age. All the heat they needed came from the little pulsed-fusion reactor, weighing only about two hundred and twenty pounds, hanging in the open mouth of the envelope. While they were climbing, its laser was zapping ten times a second, igniting the merest whiff of deuterium fuel. Once they had reached altitude, it would fire only a few times a minute, making up for the heat lost through the great gasbag overhead.
And so, even while they were almost a mile above the ground, they could hear dogs barking, people shouting, bells ringing. Slowly the vast, Sun-smitten landscape expanded around them. Two hours later, they had leveled out at three miles and were taking frequent draughts of oxygen. They could relax and admire the scenery; the on-board instrumentation was doing all the work—gathering the information that would be required by the designers of the still-unnamed liner of the skies.
It was a perfect day. The southwest monsoon would not break for another month, and there was hardly a cloud in the sky. Time seemed to have come to a stop; they resented the hourly radio reports which interrupted their reverie. And all around, to the horizon and far beyond, was that infinite, ancient landscape, drenched with history—a patchwork of villages, fields, temples, lakes, irrigation canals . . .
With a real effort, Webster broke the hypnotic spell of that ten-year-old memory. It had converted him to lighter-than-air flight—and it had made him realize the enormous size of India, even in a world that could be circled within ninety minutes. And yet, he repeated to himself, Jupiter is to Earth as Earth is to India . . .
“Granted your argument,” he said, “and supposing the funds are available, there’s another question you have to answer. Why should you do better than the—what is it—three hundred and twenty-six robot probes that have already made the trip?”
“I am better qualified then they were—as an observer, and as a pilot. Especially as a pilot. Don’t forget—I’ve more experience of lighter-than-air flight than anyone in the world.”
“You could still serve as controller, and sit safely on Ganymede.”
“But that’s just the point! They’ve already done that. Don’t you remember what killed the Queen?”
Webster knew perfectly well; but he merely answered: “Go on.”
“Time lag—time lag! That idiot of a platform controller thought he was using a local radio circuit. But he’d been accidentally switched through a satellite—oh, maybe it wasn’t his fault, but he should have noticed. That’s a half-second time lag for the round trip. Even then it wouldn’t have mattered flying in calm air. It was the turbulence over the Grand Canyon that did it. When the platform tipped, and he corrected for that—it had already tipped the other way. Ever tried to drive a car over a bumpy road with a half-second delay in the steering?”
“No, and I don’t intend to try. But I can imagine it.”
“Well, Ganymede is a million kilometers from Jupiter. That means a round-trip delay of six seconds. No, you need a controller on the spot—to handle emergencies in real time. Let me show you something. Mind if I use this?”
“Go ahead.”
Falcon picked up a postcard that was lying on Webster’s desk; they were almost obsolete on Earth, but this one showed a 3-D view of a Martian landscape, and was decorated