g into the Tower, the three cadets went directly to the office of
their unit commander. The training program at Space Academy consisted of
three cadets to a unit, with a Solar Guard officer as their teacher and
instructor. Steve Strong, captain in the Solar Guard, had been their
cadet instructor since the unit had been formed and he now smiled a
welcome as the cadets snapped to attention in front of his desk.

"_Polaris_ unit reporting as ordered, sir," said Tom, handing over the
audiogram order he had received the day before.

"Thank you, Corbett," said Strong, taking the paper. "At ease."

The three boys relaxed and broke into wide grins as Strong rounded his
desk and shook hands with each of them.

"Glad to have you back, boys," he said. "Did you enjoy your leave?"

"And how, sir," replied Tom.

"Tom's mother showed us a whale of a good time," chimed in Roger.

"And how she can cook!" Astro licked his lips involuntarily.

"Well, I hope you had a good rest--" said Strong, but was suddenly
interrupted by the sound of a small bell. Behind his desk a small
teleceiver screen glowed into life to reveal the stern face of Commander
Walters, the commander of Space Academy.

Strong turned to the teleceiver and called, "Yes, Commander Walters?"

"Did the _Polaris_ unit arrive yet, Steve?" asked the commander.

"Yes, sir," replied Strong. "They're here in my office now, sir."

"Good," said the commander with a smile. "I just received a report the
exposition will open sooner than expected. I suggest you brief the
cadets and raise ship as soon as possible."

"Very well, sir," answered Strong. The screen darkened and he turned
back to the cadets. "Looks like you got back just in time."

"What's up, sir?" asked Tom.

Strong returned to his chair and sat down. "I suppose you've all heard
about the Solar Exposition that opens on Venus next week?"

Tom's eyes lit up. "Have we! That's all the stereos and visunews and
teleceivers have been yacking about for weeks now."

"Well," said Strong with a smile, "we're going!"

The three cadets couldn't restrain themselves and burst out in a happy
shout. Then Roger calmed down enough to comment, "Sounds more like
another vacation than an assignment, sir."

"Hardly, Manning," replied Strong. "You see, every industry, society,
organization, and governmental agency is setting up exhibits at the
exposition to show the people what's taking place in their part of the
solar system.