rough the hatch
of the control deck where Tom was busy over a table of ratios for
balancing the amount of thrust from each of the reactant-power units.
The power units were to give Junior its initial thrust out of the
gravity of Tara.

"Well, Corbett," asked Connel, "how're you making out with the ratios?"

"I've finished them, sir," replied Tom, looking up at the major. His
face was drawn, his eyes red from lack of sleep. "But I just can't seem
to get a time for escaping the orbit on a true tangent."

"Have you tried making an adjustment for the overall pull of both
components?" asked Connel. "That of Tara and of Alpha Centauri on
Junior?" He picked up the paper Tom had been working on and glanced over
the figures.

"Yes, sir," replied Tom, "but I still can't seem to make it come out
right!"

"You'll get it, Tom," said Connel. "Go over it again. But remember.
Time's running out. Just one day and about twenty hours left." Connel's
voice was friendly--more friendly than at any time Tom could remember.
He smiled, and taking a fresh sheet of paper, he began the complicated
calculations of escape time all over again.

Connel slipped out of the control room and went below to the power deck,
where Astro and Mr. Shinny had been working without sleep for over fifty
hours. When Connel slipped into the room he found the two men puzzling
over a drawing board.

"What seems to be the trouble, Astro?" asked Connel.

Astro turned, startled. "We've tried building that lead baffle for the
reactant units five times now, sir," said Astro. "We're having a hard
time getting the correct amount of reactant power we need in a unit this
small."

"Maybe you're trying to make it _too_ small, Astro," commented Connel,
looking over the drawing. "Remember, this unit has but one job. To
_start_ the reaction. When the reaction fuel gets hot enough, it'll
start a reaction of the copper on Junior and sustain itself. Try a
smaller amount of the reactant. But whatever you do, keep working. Only
a day and a few hours left."

Connel looked at Shinny. "Keep him working, Mr. Shinny," he ordered. "I
know he can do it. Just keep him going."

Shinny grinned and nodded.

"I'll try, sir," said Astro, shaking his head, "but I won't guarantee
it--"

Connel cut him off with a roar. "Cadet Astro, I don't want your
guarantee! _I want that unit. Now build it!_"

Hour after hour the cadets racked their brains for what seemed like
impossible answers to