of upturned, unsmiling faces and stepped
from the dais, coming to a halt near the first desk.

"I know that all of you here have your hearts set on becoming spacemen,
officers in the Solar Guard. Most of you want to be space pilots. But
there must be astrogators, radar engineers, communication officers and
power-deck operators on each ship, and," she paused, braced her
shoulders and added, "some of you will not be accepted for any of these.
Some of you will wash out."

Dr. Dale turned her back on the cadets, not wanting to look at the
sudden pallor that washed over their faces. It was brutal, she thought,
this test. Why bring them all the way to the Academy and then give the
tests? Why not start the entrance exams at the beginning with the
classification and aptitude? But she knew the answer even before the
thoughtful question was completed. Under the fear of being washed out,
the weaker ones would not pass. The Solar Guard could not afford to have
cadets and later Solar Guard officers who could not function under
pressure.

She began handing out the tubes and, one by one, the green-clad
candidates stepped to the front of the room to receive them.

"Excuse me, Ma'am," said one cadet falteringly. "If--if--I wash out as a
cadet--as a Solar Guard officer cadet"--he gulped several times--"does
that mean there isn't any chance of becoming a spaceman?"

"No," she answered kindly. "You can become a member of the enlisted
Solar Guard, if you can pass the acceleration tests."

"Thank you, Ma'am," replied the boy and turned away nervously.

Tom Corbett accepted the tube and hurried back to his seat. He knew that
this was the last hurdle. He did not know that the papers had been
prepared individually, the tests given on the basis of the entrance
exams he had taken back at New Chicago Primary Space School.

He opened the tube, pulling out the four sheets, printed on both sides
of the paper, and read the heading on the first: ASTROGATION,
COMMUNICATIONS, SIGNALS (_Radar_)

He studied the first question.

" ... What is the range of the Mark Nine radar-scope, and how far can a
spaceship be successfully distinguished from other objects in space?..."

He read the question four times, then pulled out a pencil and began to
write.

Only the rustle of the papers, or the occasional sigh of a cadet over a
problem, disturbed the silence in the high-ceilinged room, as the
hundred-odd cadets fought the questions.

There was a sud