"That's just it," said Roger. "I remember distinctly loading all of them in the locker near the main scanner on the radar deck."
"Then we have to get it from another ship," said Tom. "The chances of getting one here, aboard the Polaris, are zero."
"Say, Roger," suddenly asked Astro, "do you think you remember enough about that triple vacuum tube to draw me a blueprint?"
"Sure," said Roger. "And you could probably build it too. But how are you going to get the inside tube vacuumized, then the second one, and finally the third. They have to be absolutely clean!"
"How about outside in space?" Astro suggested. "We could take the parts of the tube with us and assemble it out there. You can't ask for a better vacuum 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.