Though the undamaged arrays produce enough power for the station now, the problem has implications for further growth. New modules scheduled to go up will need more power. Even procedures like the docking of shuttles could increase stress on the damaged array in its present condition, Mr. Suffredini said.
Four months ago, a rotary joint was installed on a previous mission. For the last two months the joint experienced power spikes, which was the major priority the shuttle crew, STS 120, was assigned to stabilize. That's the new Saturday spacewalk. This is not the first time the ISS has had the threat of a mission critical systemic failure. A prior mission had to deal with the complete loss of computer systems and a potential catastrophic failure if they were unable to bring the system back on line, including emergency backups. Pressure is part of every day spent in space to ensure there are no mistakes because there are no do-overs.
The plan being developed by engineers and scientists working three shifts a day has a bit of the feel of a “MacGyver” episode. The damaged panels, out at the far left-hand side of the station, are hard to reach. But the teams have come up with a way to use a 50-foot-long boom that is normally used to extend the reach of the shuttle’s robotic arm. By grappling the boom with the station’s robotic arm and putting Scott E. Parazynski on the end, he will be able to reach the array and free the wire.
The leading plan then calls for Dr. Parazynski to use a wire-and-tape contraption that will be built by the astronauts after being designed by engineers on the ground. It should act like cufflinks: after threading it through reinforced holes that were put on the panels to secure them on the way to space, the ends will spread and hold the panels in place, taking the strain that the damaged panels can no longer sustain. (AP photo/NASA)
This is already an extraordinary mission with the flight mission crew commander and the leader of the space station both being female. ISS commander Peggy Whitson and Discovery shuttle commander Pam Melroy.
To learn more about the ISS, there is a paperback chock full of excellent data, Reference Guide to the International Space Station by Gary Kitmacher.