This worried him, since Silbert had become firmly attached to the notion that the Raindrop plan was an essential step to keeping the human race fed, and he had as good an appetite as anyone.
He knew, as did any reasonably objective and well-read adult, how barely the advent of fusion power and gene tailoring had bypassed the first critical point in the human population explosion, by making it literally possible to use the entire surface of the planet for either living space or the production of food. As might have been expected, mankind had expanded to fill even that fairly generous limit in a few generations.
A second critical point was now coming up, obviously enough to those willing to face the fact. Most of Earth's fourteen billion people lived on floating islands of gene-tailored vegetation scattered over the planet's seas, and the number of these islands was reaching the point where the total sunlight reaching the surface was low enough to threaten collapse of the entire food chain. Theoretically, fusion power was adequate to provide synthetic food for all; but it had been learned the hard way that man's selfishness could be raised to the violence point almost as easily by a threat to his “right” to eat natural — and tasty — food as by a threat to his “right” to reproduce without limit. As a matter of fact, the people whom Silbert regarded as more civilized tended to react more strongly to the first danger.
Raindrop had been the proposed answer. As soon as useful, edible life forms could be tailored to live in its environment it was to be broken up into a million or so smaller units which could receive sunlight throughout their bulks, and use these as “farms.”
But power units, lights, and what looked like prefabricated living quarters sufficient for many families did not fit with the idea of breaking Raindrop up. In fact, they did not fit with any sensible idea at all.
No one could live on Raindrop, or in it, permanently; there was not enough weight to keep human metabolism balanced. Silbert was very conscious of that factor. He never spent more than a day at a time on his sampling trips, and after each of these he always remained in the normal-weight part of the station for the full number of days specified on the AGT tables.
It was all very puzzling.
And as the day wore on, and more and more material was taken from the low-weight storage section of the station and netted together for the trip to Raindrop, the spaceman grew more puzzled still. He said nothing, however, since he didn't feel quite ready to question the Weisanens on the subject and it was impossible to speak privately to Bresnahan with all the spacesuit radios on the same frequency.
All the items moved were, of course, marked with their masses, but Silbert made no great effort to keep track of the total tonnage. It was not necessary, since each cargo net was loaded as nearly as possible to an even one thousand pounds and it was easy enough to count the nets when the job was done. There were twenty-two nets.
A more ticklish task was installing on each bundle a five hundred pound-second solid-fuel thrust cartridge, which had to be set so that its axis pointed reasonably close to the center of mass of the loaded net and firmly enough fastened to maintain its orientation during firing. It was not advisable to get rid of the orbital speed of the loads by “pushing off” from the station; the latter's orbit would have been too greatly altered by absorbing the momentum of eleven tons of material. The rockets had to be used.
Silbert, in loading the nets, had made sure that each was spinning slowly on an axis parallel to that of Raindrop. He had also attached each cartridge at the “equator” of its net. As a result, when the time came to fire it was only necessary to wait beside each load until its rocket was pointing “forward” along the station's orbit, and touch off the fuel.
The resulting velocity change did not, in general, exactly offset the orbital speed, but it came close enough for the purpose. The new orbit of each bundle now intersected the surface of Raindrop — a target which was, after all, ten miles in diameter and only half a mile away. It made no great difference if the luggage were scattered along sixty degrees of the satellite's equatorial zone; moving the bundles to the lock by hand would be no great problem where each one weighed about three and a half ounces.
With the last net drifting toward the glistening surface of Raindrop, Weisanen turned to the spaceman.
“What's the best technique to send us after them? Just jump off?” Silbert frowned, though the expression was not obvious through his face plate.
“The best technique, according to the AGT Safety Tables, is to go back to the rim of the station and spend a couple of days getting our personal chemistry back in balance. We've been weightless for nearly ten hours, with only one short break when we ate.”
Weisanen made a gesture of impatience which was much more visible than Silbert's frown.
“Nonsense!” he exclaimed. “People have remained weightless for a couple of weeks at a time without permanent damage.”
“Without having their bones actually turn to rubber, I grant. I don't concede there was no more subtle damage done. I'm no biophysicist, I just believe the tables; they were worked out on the basis of knowledge gained the hard way. I admit they have a big safety factor, and if you consider it really necessary I won't object to staying out for four or five days. But you haven't given us any idea so far why this should be considered an emergency situation.”
“Hmmm. So I haven't. All right, will you stay out long enough to show Brenda and me how to work the locks below, so we can get the stuff inside?”
“Why — of course — if it's that important we'll stay and do the work too. But I didn't…" Silbert fell silent as it dawned on him that Weisanen's choice of words meant that he had no intention of explaining just yet what the “emergency” was. Both newcomers must have read the spaceman's mind quite accurately at that point, since even Bresnahan was able to, but neither of them said anything.
Conversation for the next few minutes consisted entirely of Silbert's instructions for shoving off in the proper direction to reach Raindrop, and how to walk on its not-quite-zero-gravity, jelly-like surface after they reached it. The trip itself was made without incident.
Because fast movement on the surface was impossible, several hours were spent collecting the scattered bundles and stacking them by the lock. The material could not be placed inside, as most of it had to be assembled before it could go under water; so for the moment the lesson in lock management was postponed. Weisanen, after some hesitation, agreed to Silbert's second request that they return to the station for food and rest. He and his wife watched with interest the technique of getting back to it.
With four people instead of two, the velocity-matching problem might have been worse, but this turned out not to be the case. Silbert wondered whether it were strictly luck, or whether the Weisanens actually had the skill to plan their jumps properly. He was beginning to suspect that both of them had had previous space experience, and both were certainly well-coordinated physical specimens.
According to the tables which had been guiding Silbert's life, the party should have remained in the high-weight part of the station for at least eighty hours after their session of zero-gee, but his life was now being run by Weisanen rather than the tables. The group was back on the water twelve hours after leaving it.
Bresnahan still had his feeling of discomfort, with star-studded emptiness on one side and its reflection on the other, but he was given little time to brood about it.
The first material to go into the lock consisted of half a dozen yard-wide plastic bubbles of water. Silbert noted with interest that all contained animal life, ranging from barely visible crustacea to herring-sized fish.