Free Close to Critical by Hal Clement

come?"
    "I'd just add mass without being useful," Raeker replied.
    "I suppose the same could be said for me," said Rich, "but I'd like to come if there's room. I certainly don't want to hamper the work, though."
    "It will be better if you don't," admitted Sakiiro. "We'll keep in touch with this ship and the 'scaphe, though, so you'll know what's happening." He ran from the room.
    Aminadabarlee had quite obviously meant to insist upon going; after Rich's words, however, he could hardly do that. He relieved his feelings by remarking, "No one but a fool human being would have had takeoff boosters attached to an uncompleted ship."
    "The bathyscaphe is complete, except for final circuit checks and connections," another engineer replied calmly, "and the boosters were for landing as well as takeoff. As a matter of fact, they were not supposed to be connected until the last moment, and it will not be possible to tell what actually fired them until we salvage the ship. Until then, assigning blame is very much a waste of time." He stared coldly at the Drommian, and Rich stepped into the breach. Raeker had to admit the fellow was good at his job; it had seemed a virtual certainty that the big weasel was going to clean the human beings out of the room, but Rich had him calmed down below boiling point in four or five minutes.
    Raeker would have liked to hear the details, but he was occupied with the radio. The children on the bathyscaphe had heard, without understanding completely, most of the engineers' statements; and Raeker found himself doing his best to keep up their morale. They were, perfectly reasonably, frightened half to death. It wasn't as hard as he'd thought it might be, though; he hadn't talked long before he realized that the girl was doing exactly the same thing. He couldn't decide whether it was for the benefit of her father or her nonhuman companion, but his respect for the youngster went even higher.
    The rescue ship was well on the way by this time, and as the minutes clicked by the hopes of everyone on all three vessels began to mount. If the 'scaphe were in an orbit that did not touch Tenebra's atmosphere, of course, there was no danger; food and air equipment were aboard and had been operating for some time. On a straight chance basis, it seemed to Raeker that the probabilities were at least three to one that this was the case, though he was no ballistician. The computer on the rescue boat was kept busy grinding out possible orbits; the worst seemed to call for atmospheric contact within three-quarters of an hour of the accident; and if this didn't occur within a little over two hours, it wouldn't.
    There were view ports in the 'scaphe, and Easy was able to recognize some stars; but while this told them roughly which side of the planet she was on, the lack of precision measurements at her command made the information useless. At that time, there was only one side she could be on.
    It was sixty-seven minutes after the accident that Easy reported acceleration. By that time, even Aminadabarlee knew all the implications of the fact. The rescue boat was "there," in the sense that it was within half a diameter of Tenebra and nearly motionless with respect to the planet - perfectly useless, as far as the trapped children were concerned. The engineers could get a fix on the 'scaphe's transmitter and locate it within a few miles; but they couldn't compute an interception orbit inside Tenebra's atmosphere. No one knew enough about the atmosphere. The certain thing was that no interception whatever could be accomplished before the 'scaphe was so low that rockets could not be used - atmospheric pressure would be too high for them. Sakiiro reported this to the Vindemiatrix within a minute of Easy's information; then, before Aminadabarlee could start to speak, he turned to the set which he had on the depth-boat's frequency.
    "Miss Rich. Please listen carefully. Your acceleration is going to get much worse over the next few