Roger thought a moment. "It's the only thing we can do. I just hope that
Mr. Logan's coming here hasn't aroused suspicion."

"Don't worry about that," said Logan. "I told Vidac I wanted this
information about Space Academy for Billy. That seemed to satisfy him."

"I don't know," mused Tom. "He's pretty smart."

"What else can we do?" asked Astro.

"Nothing," said Tom bitterly. "Not a space-blasting thing until we get
out of here!"

* * * * *

"We've _got_ to have that triple vacuum tube," declared Roger. "That's
the only thing that will transmit a voice quickly back to Earth from
this fix out in space."

The three boys and Jeff Marshall were back in their quarters after their
first week of active duty again. They had surreptitiously begun
collecting parts for the communicator and were sorting them out on one
of the bunks when Roger mentioned the necessity for the special vacuum
tube.

"How quickly?" asked Astro.

Tom explained. "The equipment we have now is strong enough to talk to
the Academy, but it'll take about six hours for my voice to reach it.
And then another six hours for the Academy's answer to get back to us.