JOHNSON SPACE CENTER' - The International Space Station has its full set of solar arrays at last, after an almost faultless deployment today.
With engineers at Mission Control Center - Houston here watching over their shoulder electronically, the crew inched out the two halves of the final solar array wing out one at a time.
The crew stopped motion in the middle of each deployment to give the arrays time to warm in the sunlight. Past array deployments have been hampered by chemical 'stiction' as the polymers in the array-blanket surfaces bond when they are jammed against each other in their launch boxes, and warming loosens the bonds.
The station also maintained a 'solar inertial attitude,' with the Sun beaming on the same side constantly, for more of the warming effect.
Each array measures 115-by-38 feet when fully extended. First the crew deployed the array designated 1B to the aft of the starboard end of the station truss, using thrusters on the forward-facing shuttle orbiter to maintain attitude control without damaging the unfolding array.
After that they switched control of the station to engines on the Russian side of the massive spacecraft, and deployed array 3B forward toward the orbiter. That array had been packed longer than its counterpart, and gave the crew their only bad moment of the deployment when one of the 'bays' appeared out of line when it stopped at the halfway mark.
After warming in the Sun for about 45 minutes,' the wrinkled bay flattened out as the array was cranked out to its full extension.
Throughout the deployment, the combined station and shuttle crews monitored the action on the arrays carefully, both through windows and with video displays on the laptops they use to manage the station's systems. NASA managers here were prepared to rewrite the scripts for the spacewalks scheduled tomorrow and' Monday if it was deemed necessary to to outside to correct a problem.
But in the end the arrays deployed fully in a little more than two of the four-and-a-half hours allotted to the task today, and the upcoming spacewalks will go as planned."
(Via On Space.)