The Last Theorem - Arthur Charles Clarke [29]
7
GETTING THERE
The school year limped toward its end. It picked up speed remarkably in the all too brief periods when Ranjit was in his astronomy class, but the remainder of each week’s hours were in no hurry to move on at all.
For a little while Ranjit thought he had hopes of one bright—fairly bright—spot. Remembering the lecture on what they’d called the hydro-solar plan for Israel’s Dead Sea, he went back to the lecture series. But then what the lecturer was talking about was the increasing salinity of a lot of oceanfront wells, all over the world, and then about how some of the world’s great rivers no longer ran to the sea, any sea, because they were drained for farming and flushing city toilets and watering city folks’ front lawns first. Ranjit didn’t need more discouragement. After that he stayed away.
He even briefly considered trying to take, or at least pretend to take, his schooling seriously. Studying, for example, could be considered a game, and a fairly easy one to win. It did not at all resemble that insatiable thirst for learning that had marked his early consecration to the Fermat theorem. Now all he had to do was guess what questions each of his instructors would ask on each test and look up the answers. He didn’t always get it right, but then to attain a merely passing grade he didn’t have to.
None of this, of course, applied to Astronomy 101.
There Dr. Vorhulst managed to make every session a pleasure. Like what happened when they were talking about terraforming—that is, reworking planetary surfaces so that human beings could live on them. And, if you were going to do that, how did you get there to do the terraforming?
Ranjit’s answer would have been “rocket ships.” His hand was already halfway toward the raised position so that he could offer that answer when the teacher froze it mid-motion. “You’re going to say ‘rocket ships,’ aren’t you?” Dr. Vorhulst asked, addressing the whole class and particularly the dozen or so who, like Ranjit, had been putting their hands up. “All right. Let’s think about that for a bit. Let’s suppose that we want to start terraforming Mars, but all we have to work with is an absolute minimum of heavy-duty earthmoving machinery. One very big backhoe, for instance. One bulldozer. A couple of medium-size dump trucks. Fuel enough to run them all for, let’s say, six months or so. Long enough to get the job started, anyway.” He paused, eyes on a hand from the second row that had just sprouted. “Yes, Janaka?”
The boy named Janaka eagerly shot to his feet. “But, Dr. Vorhulst, there’s a whole plan to make fuel from Martian resources that are already there!”
The professor beamed at him. “You’re absolutely right, Janaka. For instance, if there really is a large amount of methane under Mars’s permafrost, as many people think there is, then we could burn that for fuel, assuming we could find some oxygen to burn it with. Of course, to do that we’d really have to have a bunch more heavy machinery, which would need a bunch more fuel to run it until the extraction plants were working.” Vorhulst gave the boy a friendly smile. “So, Janaka,” he said, “I think that if you wanted to start any terraforming in the near future, probably you’d want to fly your fuel in after all. So let’s see.”
He turned to the whiteboard and began writing. “Say six or eight tons of fuel to start. The earthmoving machines themselves—what would you say, at least another twenty or thirty tons? Now to get those at least twenty-eight tons of cargo from low earth orbit, known as LEO, to Mars, we need to put them into some kind of spaceship. I don’t know what that would mass, but let’s say the ship itself would run fifty or sixty tons, plus the fuel to get it from LEO to Mars.” He stepped back to look at his figures on the board and frowned. “I’m afraid we have a problem,” he said to the class, addressing it over his shoulder. “All that stuff won’t start out in low earth orbit, will it? Before the ship can start heading for Mars, we have to get it into LEO. And I’m afraid that’s going