The Fountains of Paradise

It was a bad year for the Tower; the second tragedy had been much more protracted, and equally public. An engineer on the counterweight, far beyond synchronous orbit, had failed to fasten her safety belt properly – and had been flicked off into space like a stone from a sling. She was in no danger, at this altitude, either of falling back to earth or of being launched on an escape trajectory; unfortunately her suit held less than two hours' air. There was no possibility of rescue at such short notice; and despite a public outcry, no attempt was made. The victim had co-operated nobly. She had transmitted her farewell messages, and then – with thirty minutes of oxygen still unused – had opened her suit to vacuum. The body was recovered a few days later, when the inexorable laws of celestial mechanics brought it back to the perigee of its long ellipse.

These tragedies flashed through Morgan's mind as he took the highspeed elevator down to the Operations Room, closely followed by a sombre Warren Kingsley and the now almost forgotten Dev. But this catastrophe was of an altogether different type, involving an explosion at or near the Basement of the Tower. That the transporter had fallen to earth was obvious, even before the garbled report had been received of a "giant meteor shower" somewhere in central Taprobane.

It was useless to speculate until he had more facts; and in this case, where all the evidence had probably been destroyed, they might never be available. He knew that space accidents seldom had a single cause; they were usually the result of a chain of events, often quite harmless in themselves. All the foresight of the safety engineers could not guarantee absolute reliability, and sometimes their own over-elaborate precautions contributed to disaster. Morgan was not ashamed of the fact that the safety of the project now concerned him far more than any loss of life. Nothing could be done about the dead, except to ensure that the same accident could never happen again. But that the almost completed Tower might be endangered was a prospect too appalling to contemplate.

The elevator floated to a halt, and he stepped out into the Operations Room – just in time for the evening's second stunning surprise.

43. Fail-Safe

Five kilometres from the terminus, driver-pilot Rupert Chang had reduced speed yet again. Now, for the first time, the passengers could see the face of the Tower as something more than a featureless blur dwindling away to infinity in both directions. Upwards, it was true, the twin grooves along which they were riding still stretched forever – or at least for twenty-five thousand kilometres, which on the human scale was much the same. But downwards, the end was already in sight. The truncated base of the Tower was clearly silhouetted against the verdant green background of Taprobane, which it would reach and unite with in little more than a year.

Across the display panel, the red ALARM symbols flashed yet again. Chang studied them with a frown of annoyance, then pressed the RESET button. They flickered once, then vanished.

The first time this had happened, two hundred kilometres higher, there had been a hasty consultation with Midway Control. A quick check of all systems had revealed nothing amiss; indeed, if all the warnings were to be believed, the transporter's passengers were already dead. Everything had gone outside the limits of tolerance.

It was obviously a fault in the alarm circuits themselves, and Professor Sessui's explanation was accepted with general relief. The vehicle was no longer in the pure vacuum environment for which it had been designed; the ionospheric turmoil it had now entered was triggering the sensitive detectors of the warning systems.

"Someone should have thought of that," Chang had grumbled. But, with less than an hour to go, he was not really worried. He would make constant manual checks of all the critical parameters; Midway approved, and in any case there was no alternative.

Battery condition was, perhaps, the item that concerned him most. The nearest charging point was two thousand kilometres higher up, and if they couldn't climb back to that they would be in trouble. But Chang was quite happy on this score; during the braking process the transporter's drive-motors had been functioning as dynamos, and ninety percent of its gravitational energy had been pumped back into the batteries. Now that they were fully charged, the surplus hundreds of kilowatts still being generated should be diverted into space through the big cooling fins at the rear. Those fins, as Chang's colleagues had often pointed out to him, made his unique vehicle look rather like an old-time aerial bomb. By this time, at the very end of the braking process, they should have been glowing a dull red. Chang would have been very worried indeed had he known that they were still comfortably cool. For energy can never be destroyed; it has to go somewhere. And very often it goes to the wrong place.