The other two power and communications stations which led and lagged Space Lab One by 120 deg. each, would combine to command a complete view of Earth, lacking only a circle within the arctic regions, so that they could provide power and communications for the entire world--a fact which had been the political carrot which had united Earth in the effort to create the labs with their combined technologies. The danger of such powerful instruments as Hot Rod, concentrating megawatt beams of solar energy for relay to earth, and which could also be one of man's greatest weapons if it fell into unscrupulous hands, had been carefully played down, and also carefully countered in the screening by the Security Forces of U.N. of the personnel board. * * * * * T minus three and counting. On the zero signal Mike in the engineer's quarters would change the now idly-bubbling air jets in the rim-rivers over to the fully-directional drive jets necessary to spin the fluid in counter-rotation through the rim tanks. The suiting-up and strapping down were probably unnecessary, Mike thought, but in space you don't take chances. "T minus two and counting." Bessie's voice rang over the com circuit in officially clipped clarity. From the physics lab came a rather oddly pitched echo. "Allee allee in free fallee! Hold it, please, as Confusion would say! Paul forgot to secure the electrolite for the ECM equipment. Can't have these five-gallon bottles bouncing around!" "And we can't have you bouncing around either, Dr. Chi Tung. Get that soup under wraps quick. How much time do you need?" came the captain's voice from his console angled over Bessie's head. Clark's voice could be heard murmuring into his Earth-contact phone. "T minus two. Holding." Less than two minutes later, Dr. Chi released the hold by announcing briefly, "Machine shop and physics department secure." "T minus two and counting...." "T minus one and counting...." Bessie continued officially. "Fifty, forty, thirty, twenty...." The faint whine of high-speed centrifugal compressors could be heard through the ship. "Ten...." The jets that had previously bubbled almost inaudibly took on the sound of a percolating coffee pot. "... Four, three, two, one, mark." The bubbling became a hiss that settled into a soft susurrus of background noise, as the jets forced air through the river of water in the circular tanks of the rim. The water began to move. By reaction, the wheel took up a slow, circular motion in the opposite direction. Then, gently, the wheel shook itself and settled into a complacently off-center motion that placed Bessie somewhere near the actual center of rotation. "We're out of balance, Mr. Blackhawk," said the captain, one hand on the intercom switch. "Bessie, ask the Cow what's off balance." It was Mike's voice from engineering control. "Thought we had this thing trued up like a watch."