dholds. The ship
had stopped acceleration and was at no-weight again. As he neared the
analysis section, it went into deceleration, but the pressure was not too
bad. He made his way against it easily.

The chief analyst was waiting for him. "We have everything you need,
Lieutenant, except the orbital stuff. We'll do the best we can on that
and have an estimate in a few minutes. Meanwhile you can mark up your
figures. Incidentally, what power are you going to use to move the
asteroid?"

"Nuclear explosions," Rip said, and saw the chief's eyes pop. He added,
"With conventional chemical fuel for corrections."

He felt rising excitement. The whole ship seemed to have come to life.
There was excited tension in the computer room when he went in with the
chief. Spacemen, all mathematicians, were waiting for him. As the chief
led him to a table, they gathered around him.

Rip took command. "Here's what we're after. I need to plot an orbit that
will get us out of the asteroid belt without collisions, take us as close
to the sun as possible without having it capture us, and land us in space
about ten thousand miles from Earth. From then on I'll throw the asteroid
into a braking ellipse around the earth, and I'll be able to make any
small corrections necessary."

He spread out a solar system chart and marked in the positions of the
planets as of that moment, using the daily almanac. Then he put down the
position of the asteroid, taking it from the paper the chief analyst
handed him.

"Will you make assignments, Chief?"

The chief shook his head. "Make them yourself, Lieutenant. We're at your
service."

Rip felt a little ashamed of some of the unkind things he had said about
spacemen. "Thank you." He pointed to a spaceman. "Will you calculate the
inertia of the asteroid, please?" The spaceman hurried off. "First thing
to do is plot the orbit as though there were no other bodies in the
system," Rip said. "Where's Santos?"

"Here, sir." The corporal had come in unnoticed with Rip's reference
books.

Rip had plotted orbits before, but never one for actual use. His palms
were wet as he laid it out, using prepared tables. When he had finished
he pointed to a spaceman. "That's it. Will you translate it into analogue
figures for the computer, please?" He assigned to others the task of
figuring out the effect Mercury, the sun, and Earth would have on the
orbit, using an assumed speed for the asteroid.

To the chief analyst h