During the few minutes they had left, they casually discussed the chances of the senior space cadets against the enlisted guardsmen in a forthcoming mercuryball game, and then went up to the forward compartment of the Polaris, which served as a temporary observatory for Professor Sykes.

The Chief Astrophysicist of Space Academy, Professor Barnard Sykes, was a man of great talent and even greater temper. Referred to as Barney by the cadet corps, he was held in high regard and downright fear. There were few cadets who had escaped his scathing tongue when they had made a mistake and practically the entire student body had, at one time or another, singly and in unison, devoutly wished that a yawning hole would open up and swallow them when he began one of his infamous tirades. Even perfection in studies and execution by a cadet would receive a mere grunt from the cantankerous professor. Such temperament was permissible at the Academy by an instructor only because of his genius and for no other reason. And Professor Sykes fitted the bill. It was by sheer devotion to his work and single-mindedness of purpose that he was able to become a leading scientist in his field. Professor Sykes had been assigned, at his request, to the Roald expedition. As the leading scientist, it was his job to evaluate every new discovery made during the trip out to the distant satellite, and later make observations on the colony itself. Scientifically, and in a sense ultimately, the success or failure of the Roald expedition would rest on his round hunched shoulders.

When the three cadets and Jeff Marshall entered the observatory, they found Professor Sykes bending over a calculating machine checking some figures. Apparently finding a mistake, he muttered to himself angrily and started over again. Roger stepped forward.

"I can handle a calculator pretty well, sir," Roger said. "You want me to do it for you?"

Sykes whirled around and glared at the blond-haired cadet. "What's your name?" he snapped.

"Why—Cadet Manning, sir," replied Roger.

"Cadet Manning, do you see this calculator?" Sykes pointed to the delicate instrument that could add, subtract, divide, and multiply, in fractions and whole numbers, as well as measure the light years in sidereal time.

"Yes, sir," said Roger.

"Cadet Manning," continued Sykes, "I perfected that machine. Built the first one myself. Now offhand, wouldn't you say I would know how to operate it?"

"Yes, sir," stammered Roger. "But I just wanted to help, sir."