Space: Those Balky Computers Again

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Aware of the machines' fickle past, the controllers promptly shut down the No. 3 computer on Columbia in order to keep it as a fail-safe reserve and relegated No. 4 to managing the vehicle's environmental systems. The fifth computer was on standby. Later, when he was safely on the ground, Young confessed: "When the first one went, my knees shook. When the second went, I turned to jelly." Eventually, Mission Control was able to command No. 2 back into action, although its performance was erratic. No. 1 remained dead for the rest of the flight.

The situation was never life-threatening, since a computer was always available to take charge of the ship. Still, the controllers decided to wave off a landing for several orbits while hundreds of engineers in Houston pored over data in an effort to discover the cause of the failures. The controllers were afraid that the difficulty, whatever it was, would spread through the system and bring down all the ship's computers. Without a computer, even a John Young probably would not have been able to take Columbia safely out of orbit because of the complex sequence of rocket firings needed to control the craft's fiery plunge through the atmosphere.

At one point during the crisis, Young, who had been at the helm for 8½ hours without a break, retired for a nap. As the shuttle program boss, Air Force Lieut. General James Abrahamson, later explained, "There's an old rule among test pilots: when there is a problem, then just slow down and back out."

While Young's copilot, Air Force Major Brewster Shaw, took charge, one of three inertial measuring units, which sense any changes in the spacecraft's speed or direction, mysteriously broke down. In addition, the laws of celestial mechanics added a political problem. Each extra swing around the earth changed Columbia's path. As a result, when the ship swooped out of its last orbit, instead of coming in south of Australia and over the western Pacific, it passed only 80 miles above eastern Siberia in the militarily sensitive area of the Sakhalin Peninsula where Soviet aircraft shot down a South Korean jet last September. Never before had a manned American spacecraft flown so low over Soviet territory; happily for NASA, there were no grumbles from the Kremlin.

The final electronic indignity came at the end of Young's textbook landing. As the orbiter's nose thudded to rest on its front landing gear, the No. 2 computer shut down again. The following day NASA announced it would not sanction the next shuttle flight, scheduled for Jan. 30, until the computer difficulties are resolved.

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