
asteroids?" Loring Sheer had been trying to adjust to the idea of imminent
death, but now the engineer was confused again.
"We can't hide behind one. What we need for breathing space is a cluster. I've
got the computer looking for one we can reach before the Seeker reaches us."
He checked the missile's progress. "Luckily, it's in no hurry-it knows we
can't get away." He pressed the compute key. "Hold your breath."
"What are you calculating, Vern?" Mary Vissuto had been too busy on Mandrake
with the children and with her own work to pay much attention to the celestial
mechanics of the Belt.
"Asteroid groups. The asteroids move all the time relative to each other." And
when Mary still showed no sign of understanding, "They move, you see, but the
law of averages means that there have to be temporary clusters, continually
forming and dissolving. The trick is to find one near enough to do us some
good. Then we move over and snuggle up into the middle of the group."
He did not take time to explain the tricky part of what he was doing. The
bodies of the Asteroid Belt ranged in size from Ceres, a giant by asteroid
standards at seven hundred and fifty kilometers, down to free-falling
moun-tains and on to the pea-sized and smaller pebbles. Everything from worlds
to sand grains moved in its own complicated orbit, defined by the
gravitational forces of sun and planets, by solar wind and radiation pressure,
and by asteroid interactions.
Vern's first task was to choose reasonable size limits. He had on file the
orbit parameters for every Belt body of --more than fifty meters in diameter,
and he had set the required number of bodies to one thousand, with a cluster
radius of five hundred kilometers. If the computer could find nothing that
matched those requirements, he would have to decrease the number of bodies in
the cluster or increase the permitted cluster radius. Each of those options
would make it more difficult for the Pelagic to hide. And the hiding place
would be temporary, whatever he did. The Seeker would patiently search every
body of a cluster until it again encountered the unique signature of the
Pelagic.
The other two in the control room had not needed Perry's explanation to know
what he was doing. Their eyes were fixed on the displays. "It's found some,"
said Palance as the computation ended. "Four of them!"
Perry shrugged. "Yeah, but look at the distances. We can forget the first
three-the Seeker would catch us before we got there. It's number four, or
nothing."
"That cluster's not even close to our present trajectory." Sheer was peering
at the tabulation. "We'd have to burn all the fuel we've got to make that
course change."
"You'll never find a better use for it." Mimi Palance had already made up her
mind. "Vern, give me a flight path."
"Doing it." Perry was at the console. Hope was the biggest delusion, but what
else was there to do? "Loring, make sure you're ready for full acceleration.
I'm going to assume that you can squeeze out a quarter gee."
"You'll be lucky." But Loring Sheer was looking better as he hurried out.
Something to do, anything to do. Even if he blew the engines apart, that was
better than sitting around watching the approach of the Seeker.
"A quarter gee!" protested Mary Vissuto. "We haven't had a tenth of that since
we left Mandrake. The cabins and galley aren't ready f* it."
"They'd better be," said Perry. "In about two minutes. I'm programming for
maximum thrust as soon as Sheer can give it to us."
"We'll never get things tied down in time." But Mary, too, was hurrying out,
leaving Palance and Perry alone in the control room.
"So we go sit in the middle of the cluster." Perry spoke in a dry, controlled
voice, as though they were discussing some academic problem of orbital
rendezvous. At the same time, he was fine-tuning the trajectory, seeking a
region where the cluster bodies were converging. "What then, Mimi? Loring and
Mary still don't understand. They think this gives us a chance. It doesn't. It
gives us a short reprieve. There's no way that the Pelagic can escape a