Tom leaned back in the pilot's seat and turned to the captain. "All stations ready, sir."
"Good! What next?" asked Strong.
"Ask spaceport tower for blast-off clearance--"
Strong nodded. Tom turned back to the microphone, and without looking, punched a button in front of him.
"Rocket cruiser--" He paused and turned back to Strong. "What name do I give, sir?"
Strong smiled. "_Noah's Ark_--"
"Rocket cruiser _Noah's Ark_ to spaceport control! Request blast-off clearance and orbit."
Once again a thin metallic voice answered him and gave the necessary instructions.
On and on, through every possible command, condition or decision that would be placed in front of him, Tom guided his imaginary ship on its imaginary flight through space. For two hours he pushed buttons, snapped switches and jockeyed controls. He gave orders and received them from the thin metallic voices. They answered him with such accuracy, and sometimes with seeming hesitation, that Tom found it difficult to believe that they were only electronically controlled recording devices.
Once, when supposedly blasting through space at three-quarters space speed, he received a warning from the radar bridge of an approaching asteroid. He asked for a course change, but in reply received only static. Believing the recording to have broken down, he turned inquiringly to Captain Strong, but received only a blank stare in return. Tom hesitated for a split second, then turned back to the controls. He quickly flipped the teleceiver button on and began plotting the course of the approaching asteroid, ignoring for the moment his other duties on the control deck. When he had finished, he gave the course shift to the power deck and ordered a blast on the starboard jet.
He waited for the course change, saw it register on the gauges in front of him, then continued his work.
Strong suddenly leaned over and clapped him on the back enthusiastically.
"Good work, Corbett. That broken recording was put there intentionally to trap you. Not one cadet in twenty would have had the presence of mind you showed in plotting the course of that asteroid yourself."
"Thank you, sir," stammered Tom.
"That's all--the test is over. Return to your quarters." He came over and laid a hand on Tom's shoulder. "And don't worry, Corbett. While it isn't customary to tell a cadet, I think you deserve it. You've passed with a perfect score!"
"I have, sir? You mean--_I really passed?_"
"Next step is Manning," said Strong. "You've done as much as one cadet can do."
"Thank you, sir"--Tom could only repeat it over and over--"thank you, sir--thank you."
Dazed, he saluted his superior and turned to the door. Two hours in the pilot's chair had made him dizzy. But he was happy.
Five minutes later he slammed back the sliding door and entered the quarters of 42-D with a lusty shout.
"Meet Space Cadet Corbett--an Earthworm who's just passed his control-deck manual operations exam!"
Astro looked up from a book of tables on astrogation and gave Tom a wan smile.
"Congratulations, Tom," he said, and turned back to his book, adding bitterly, "but if I don't get these tables down by this afternoon for my power-deck manual, you're sunk."
"Say--what's going on here?" asked Tom. "Where's Roger? Didn't he help you with them?"
"He left. Said he had to see someone before taking his radar-bridge manual. He helped me a little. But when I'd ask him a question, he'd just rattle the answer off so fast--well, I just couldn't follow him."
Suddenly slamming the book shut, he got up. "Me and these tables"--he indicated the book--"just don't mix!"
"What's the trouble?"
"Ah--I can get the easy ones about astrogation. They're simple. But it's the ones where I have to _combine_ it with the power deck."
"Well--I mean--what specifically?" asked Tom softly.
"For instance, I've got to find the ratio for compression on the main firing tubes, using a given amount of fuel, heading for a given destination, and taking a given time for the passage."
"But that's control-deck operations--as well as astrogation and power!"
exclaimed Tom.
"Yeah--I know," answered Astro, "but I've still got to be able to do it.
If anything happened to you two guys and I didn't know how to get you home, then what?"
Tom hesitated. Astro was right. Each member of the unit had to depend on the other in any emergency. And if one of them failed...? Tom saw why the ground manuals were so important now.
"Look," offered Tom. "Suppose we go over the whole thing again together.
Maybe you're fouled up on the basic concept."
Tom grabbed a chair, hitched it close to the desk and pulled Astro down beside him. He opened the book and began studying the problem.
"Now look--you have twenty-two tons of fuel--and considering the position of your ship in space--"
As the two boys, their shoulders hunched over the table, began reviewing the table of ratios, across the quadrangle in the examination hall Roger Manning stood in a replica of a rocket ship's radar bridge and faced Captain Strong.
"Cadet Manning reporting for manual examination, sir." Roger brought up his arm in a crisp salute to Captain Strong, who returned it casually.
"Stand easy, Manning," replied Strong. "Do you recognize this room?"
"Yes, sir. It's a mock-up of a radar bridge."
"A workable mock-up, cadet!" Strong was vaguely irritated by Roger's nonchalance in accepting a situation that Tom had marveled at. "You will take your manuals here!"
"Yes, sir."
"On these tests you will be timed for both efficiency and speed and you'll use all the tables, charts and astrogation equipment that you'd find in a spaceship. Your problems are purely mathematical. There are no decisions to make. Just use your head."
Strong handed Roger several sheets of paper containing written problems.
Roger shuffled them around in his fingers, giving each a quick glance.
"You may begin any time you are ready, Manning," said Strong.
"I'm ready now, sir," replied Roger calmly. He turned to the swivel chair located between the huge communications board, the adjustable chart table and the astrogation prism. Directly in front of him was the huge radar scanner, and to one side and overhead was a tube mounted on a swivel joint that looked like a small telescope, but which was actually an astrogation prism for taking sights on the celestial bodies in space.
Roger concentrated on the first problem.
" ... you are now in the northwest quadrant of Mars, chart M, area twenty-eight. You have been notified by the control deck that it has been necessary to jettison three quarters of your fuel supply. For the last five hundred and seventy-nine seconds you have been blasting at one-quarter space speed. The four main drive rockets were cut out at thirty-second intervals. Making adjustment for degree of slip on each successive rocket cutout, find present position by using cross-fix with Regulus as your starboard fix, Alpha Centauri as your port fix."
Suddenly a bell began to ring in front of Roger. Without hesitation he adjusted a dial that brought the radar scanner into focus. When the screen remained blank, he made a second adjustment, and then a third and fourth, until the bright white flash of a meteor was seen on the scanner. He quickly grabbed two knobs, one in each hand, and twisted them to move two thin, plotting lines, one horizontal and one vertical, across the surface of the scanner. Setting the vertical line, he fingered a tabulating machine with his right hand, as he adjusted the second line with his left, thus cross-fixing the meteor. Then he turned his whole attention to the tabulator, ripped off the answer with lightning moves of his fingers and began talking rapidly into the microphone.