"I think," he said, "that the saboteur may have been a meteor that punctured the balloon, and the nitrogen escaping through the hole it made is now producing enough thrust to keep that cable taut. Though," he added thoughtfully, "I don't see why the servos couldn't maintain the beam to Thule—though obviously, they couldn't."
"How dangerous is such a puncture?" asked the captain. "How seriously would Hot Rod be damaged? How soon must it be repaired?"
"The puncture itself shouldn't be too dangerous. Even if all the nitrogen's gone, the balloon's in a vacuum and won't collapse—and that's about the only serious effect a puncture would have. Just a moment. We'll estimate its size by the thrust it's giving the ship," he added, and turned to Bessie.
"Ask the Cow whether we're getting thrust on the ship; and if so, how much. Wait a minute," he added, "if you ask for thrust on the ship, she'll say there isn't any because Hot Rod would be pulling us, not pushing. And if you ask her for the thrust on Hot Rod, she hasn't got any sensors out there.
"Hm-m-m. Ask her if we have added any off-orbit velocity; and if so how much."
The computer displayed the answer almost as soon as she received the question.
"Well," said Mike, "that's not too large a hole. Ask her how ... let's see ... how many pounds of thrust that velocity represents. That way we don't confuse her with whether it's push or pull."
The Cow displayed the answer, six hundred forty pounds of thrust.
"O.K.," said Mike. "Thanks." Then to the captain and the scientist and Security officer who were waiting beside him: "The puncture is obviously small enough to serve as a jet, rather than to have let the nitrogen out in one whoosh, since that would have given you far more than six hundred forty pounds of thrust. Therefore, it will probably be quite simple to patch the hole.