l microphone
and waited for an acknowledgment. It came almost immediately.

"Cadet Corbett ready for testing," a voice crackled thinly over the
loud-speaker.

"Very well. Proceed."

Seated in front of the scanner screen on the control deck of the rocket
cruiser _Polaris_, Captain Steve Strong replaced the microphone in its
slot and watched a bulky figure in a space suit step out of the air lock
and drift away from the side of the ship. Behind him, five boys, all
dressed in the vivid blue uniforms of the Space Cadet Corps, strained
forward to watch the lone figure adjust the nozzles of the jet unit on
the back of his space suit.

"Come on, Tom!" said the biggest of the five boys, his voice a low,
powerful rumble as he rooted for his unit mate.

"If Tom makes this one," crowed the cadet next to him, a slender boy
with a thick shock of close-cropped blond hair, "the _Polaris_ unit is
home free!"

"This is the last test, Manning," replied one of the remaining three
cadets, the insigne of the _Arcturus_ unit on the sleeve of his uniform.
"_If_ Corbett makes this one, you fellows deserve to win."

Aboard the rocket cruiser _Polaris_, blasting through the black void of
space two hundred miles above Earth, six Space Cadets and a Solar Guard
officer were conducting the final test for unit honors for the term. All
other Academy units had been eliminated in open competition. Now, the
results of the individual space orientation test would decide whether
the three cadets of the _Arcturus_ unit or the three cadets of the
_Polaris_ unit would win final top unit honors.

Roger Manning and Astro kept their eyes glued to the telescanner screen,
watching their unit mate, Tom Corbett, drift slowly through space toward
his starting position. The young cadet's task was basically simple; with
his space helmet blacked out so that he could not see in any direction,
he was to make his way back to the ship from a point a mile away, guided
only by the audio orders from the examining officer aboard the ship. His
score was measured by the time elapsed, and the amount of corrections
and orders given by the examining officer. It was an exercise designed
to test a cadet's steadiness under emergency conditions of space.

The three members of the _Arcturus_ unit had completed their runs and
had returned to the ship in excellent time. Roger and Astro had also
taken their tests and now it depended on Tom. If he could return to the
_Polaris_ in l