Nearly two hours had passed and Tom knew that they would soon be in radar range of the Ganymede garrison. The pressure in the air lock must now be within ten units of zero. Suddenly, overhead, the audioceiver loud-speaker crackled into life.
"Attention! This is Ganymede traffic control. Identify yourself immediately with authorized code!"
Coxine glared at Tom and put his hand on the air-lock valve. "Last time, Corbett. Either you give me the Solar Guard recognition signal, or your buddies are finished!"
Tom gulped. He had no assurance that Coxine would release Roger and Astro, even if he did give him the signal. But he knew there was no choice. He looked up at Coxine.
"Do I have your word as an _Earthman_ that nothing will happen to them?" he asked quietly.
Coxine laughed. "Sure. I'll give you my word. I'll even bring them up here so they can see the show and then let you go afterward. But by the time I'm finished with the Ganymede colony the Solar Guard will have your hides for handing out their secrets."
Tom knew what the pirate said was true. He was taking a gamble now. A gamble that by this time his signal on the _Polaris_ had been picked up and a fleet of ships would be on their trail.
"Attention! Attention! Identify yourselves immediately!" The voice from the Ganymede traffic-control tower came over the audioceiver again. Coxine's face twisted into a half-smile.
"Well, Corbett, do I get the signal or don't I?"
"Tell them you're a Solar Guard armed freighter." Tom's voice was low. "You're assigned to operation 'Vista.'"
"Vista?" said Coxine excitedly. "Is that the code word? Vista?"
Coxine gave the valve a number of turns in the opposite direction and jumped to the teleceiver. He flipped the key open and called Wallace aboard the _Polaris_. "When they ask you for identification, tell them you're working on operation Vista. That's the key word. Vista!"
Coxine then turned to the audioceiver and spoke in confident, assured tones. "Attention, Ganymede traffic control! This is armed freighter _Samson_, assigned on project Vista. Request clearance for approach and touchdown on Ganymede spaceport!"
"You are properly identified, _Samson_," replied Ganymede. "Proceed on your present course. End transmission."