Strong looked at his watch and rose to his feet. "It's getting late.

Check the _Polaris_ over and stand by to raise ship in an hour."

"Yes, sir," said Tom.

The cadets came to attention, preparing to leave.

"One thing more! Don't get the idea that this is going to be a s.p.a.ce lark," said Strong. "It's very important for the people of the Solar Alliance to know what kind of work we're doing here at the Academy. And you three have been selected as representatives of the entire Cadet Corps. So see that you conduct yourselves accordingly. All right, dismissed!"

The three cadets saluted sharply and filed out of the room, their skipper's final words ringing in their ears.

Fifteen minutes later, having packed the necessary gear for the extended trip, the _Polaris_ unit rode the slidewalk through the gra.s.sy quadrangle and the cl.u.s.ter of Academy buildings, out toward the s.p.a.ceport. In the distance they could see the rocket cruiser _Polaris_, poised on the launching ramp, her long silhouette outlined sharply against the blue sky. Resting on her four stabilizer fins, her nose pointed toward the stars, the ship looked like a giant projectile poised and ready to blast its target.

"Look at her!" exclaimed Astro. "If she isn't the most beautiful ship in the universe, I'll eat my hat."

"Don't see how you could," drawled Roger, "after the way you put away Mrs. Corbett's pies!"

Tom laughed. "I'll tell you one thing, Roger," he said, pointing to the ship, "I feel like that baby is as much my home as Mom's and Dad's house back in New Chicago."

"All right, all right," said Roger. "Since we're all getting sloppy, I have to admit that I'm glad to see that old thrust bucket too!"

Presently the three cadets were scrambling into the mighty s.p.a.ceship, and they went right to work, preparing for blast-off.

Quickly, with sure hands, each began a systematic check of his station.

On the power deck Astro, a former enlisted Solar Guardsman who had been admitted to the Cadet Corps because of his engineering genius, stripped to the waist and started working on the ship's ma.s.sive atomic engines. A heavy rocketman's belt of tools slung around his waist, he crawled through the heart of the ship, adjusting a valve here, turning a screw there, seeing that the reactant feeders were clean and clear to the rocket firing chambers. And last of all he made sure the great rocket firing chambers were secure and the heavy sheets of lead baffling in place to protect him from deadly radioactivity.

On the radar bridge in the nose of the ship, Roger removed the delicate astrogation prism from its housing and cleaned it with a soft cloth.

Replacing it carefully, he turned to the radar scanner, checking the intricate wiring system and making sure that the range finders were in good working order. He then turned his attention to the intercom.

"Radar bridge to control deck," he called. "Checking the intercom, Tom."

Immediately below, on the control deck, Tom turned away from the control panel. "All clear here, Roger. Check with Astro."

"All clear on the power deck!" The big Venusian's voice boomed over the loud-speaker. The intercom could be heard all over the ship unless the many speakers were turned off individually.

Tom turned his attention back to the great control panel, and one by one tested the banks of dials, gauges, and indicators that controlled the rocket cruiser. Tom Corbett had wanted to be a s.p.a.ce Cadet as long as he could remember. After taking the entrance exams, he had been accepted for the rigid training that would prepare him to enter the ranks of the great Solar Guard. He had met his two unit-mates, Roger and Astro, on his very first day at the Academy, and after a difficult beginning, adjusting to each other's personalities and the discipline of the Academy routine, the three boys had become steadfast friends.

As control-deck cadet and pilot, Tom was head of the unit, second-in-command to Captain Strong. And while he could issue orders to Astro and Roger and expect to be obeyed, the three cadets all spoke their minds when it came to making difficult decisions. This had solidified the three cadets into a fighting, experienced, dependable unit.

Tom made a final check on the gravity generator and turned to the intercom.

"All departments, report!" he called.

"Radar bridge checks in O.K.," replied Roger.

"Power deck checks in on the nose, Tom," reported Astro.

"Right! Stand by! We blast as soon as the skipper gets around."

Tom turned to the teleceiver and switched it on. The screen blurred and then steadied into a view of the s.p.a.ceport outside. Tom scanned the launching ramp below, and, satisfied it was clear, he switched the teleceiver to the s.p.a.ceport traffic-control circuit.

"Rocket cruiser _Polaris_ to s.p.a.ceport control," he called. "Come in, s.p.a.ceport control. Request orbit clearance."

"s.p.a.ceport traffic control to _Polaris_," reported the traffic officer, his face in focus on the teleceiver screen. "Your orbit has been cleared for blast-off. Orbit number 3847--repeat, 3847--raise ship when ready!"

"Orbit 3847," repeated Tom. "End transmission!"

"End transmission," said the officer. Tom flipped off the teleceiver and the officer's face disappeared.

At the rear of the control deck, Captain Strong suddenly stepped through the hatch and dropped his black plastic s.p.a.ce bag on the deck. Tom got up and saluted sharply.

"_Polaris_ ready to blast off, sir," he said. "Orbit cleared."

"Very well, Corbett," replied Strong, returning the salute. "Carry on!"

Tom turned back to the control board and flipped on the intercom.

"Control deck to power deck! Energize the cooling pumps!"

"Cooling pumps, aye!" said Astro.

From the power deck, the ma.s.sive pumps began their whining roar. The great ship shuddered under the pressure.

Tom watched the gauge that indicated the pressure control and then called into the intercom.

"Radar bridge, do we have a clear trajectory?'

"All clear forward and up, Tom," reported Roger from the radar bridge.

"Strap in for blast-off!" bawled the curly-haired cadet.

Captain Strong took his place in the pilot's chair next to Tom and strapping himself in snapped out, "Feed reactant!"

Spinning a small wheel at the side of the control panel, Tom reported, "Feeders at D-9 rate, sir!"

Then, as the hiss of fuel pouring into the mighty engines of the ship blended with the whine of the pumps, Tom snapped out a third order. "Cut in take-off six yards!"

Receiving acknowledgment from below, he grasped the master blast-off switch and watched the sweeping hand of the astral chronometer.

"Stand by to raise ship!" he yelled. "Blast off minus--five--four--three--two--one--_zero_!"

He pulled the switch.

Slowly, the rockets blasting evenly, the giant ship lifted itself free of the ground. Then, gaining speed, it began rocketing away from the Earth. Like a giant shining bullet, the great s.p.a.ceship blasted through the dark void of s.p.a.ce, her nose pointed to the distant misty planet of Venus.

Once again Tom Corbett and his unit-mates had embarked on a mission for the Solar Guard.

CHAPTER 2