cuum than outer space."

Tom grinned and slapped the big Venusian on the back. "Astro, you're the
hero of the day. Come on, Roger, start drawing that tube! Astro can make
it on the power deck as if he were repairing something. Make it as
simple as possible."

"Right," said Roger, "all I need is the vacuum and of course the copper
filament inside the inner third tube for sending and receiving. We can
make it so the tubes screw together inside of each other and then seal
them."

"Right," said Astro.

"Meantime," said Tom, "Jeff and I will get you a set of earphones, if we
have to tear them off the head of the radarman!"

Meanwhile, in Vidac's quarters, the second-in-command was facing the
irascible Professor Sykes.

"Say that again, Professor," said Vidac. Sykes was standing before him
holding a slip of paper in his hand.

"I said," the professor snorted, "that in forty-eight hours and some odd
minutes we will be passing through a very thick cluster of asteroids,
about ten thousand miles in depth."

"Is it on our present course?" asked Vidac.

"Yes," replied Sykes. "We'll have to go around it. I wouldn't give you a
plugged credit for our chances of getting through it."

"I didn't ask you for your opinion!" snapped Vidac. "All right, you've
given me your information. Now get out!"

Sykes abruptly turned and left the lieutenant governor's compartment.
Alone, Vidac paced the floor. After a moment of deep thought he snapped
his fingers in decision and turned on the ship's intercom.

"Corbett! Manning! Astro!" he bellowed. "Report to the control deck on
the double."

A few moments later the three cadets stood before Vidac at rigid,
stone-faced attention. Vidac turned on the chart projection screen and
pointed to their position in space.

"Professor Sykes has just warned me that the fleet is approaching a
freakish asteroid cluster," he announced. "He estimates it to be of this
size." Vidac swept his arm over the chart, taking in most of the space
directly in front of their path. "To go around it, over it, or under it
would mean altering the course of the whole fleet and losing about six
days' transit time." He turned back to the cadets who had been watching
closely. "I want you three to see if you can find a route through the
belt and save us the detour time." He glanced at his wrist chronograph.
"The belt is about forty-one hours ahead of us now. Take a rocket scout,
look it over, and report back to me."

"