The hills ended as abruptly as they began, after less than two hours driving on the thirty-fourth day. We still had almost eighteen hundred miles to go.
"Clear ahead," Helene called back. "How fast?"
We both knew we couldn't possibly make it in the forty days we'd hoped, and that if we did it wouldn't do us any good. We'd used up slightly over six days' worth of fuel for the 'dozer cutting slots for the tractor. There would be a balance between time and fuel that would give us the most possible days to use the 'dozer, when and if we got there.
"What's the active tank reading?" I asked.
"Point four."
Add that to the three inactive tanks, plus the two in the 'dozer, plus the auxiliaries, plus the one remaining salvaged "extra" strapped to the 'dozer's hood. Split it all up in terms of average consumption per mile at a given number of miles per hour. Balance it against miles to the landing site, days left to L-day, and 'dozer average consumption per day....
Ten minutes later I called her and asked: "Can you take an extra hour of driving a day?"
"If you can, so can I. You've got the rough seat."
I knew it was bravado; I did have the rougher ride, but she was a woman, and not a very big one, at that. On the other hand, I didn't dare assume anything but that she meant it. She was just itching for a chance to blow up in my face.
"Okay," I said, "sixteen hours a day, and average fourteen miles an hour. If your fuel consumption indicates more than point two over cruising, let me know."