But that, and all other sources of satisfaction, was wiped out by news that came back from the Moonship a bare six hours later.
The Moonship 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 Moonship could not possibly have carried. And everything worked out. The ship 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 Moonship 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 ship 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 Moonship 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 Moonship 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 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.