November 03, 2007
Repair a Success!
EVA Officer Dina Contella said there was "a lot of cheering going on in Mission Control" today as a result of the successful repair of the P6 solar array. The 7-hour and 19-minute spacewalk by Scott Parazynski and Doug Wheelock laced up the torn array so it could be fully extended.
As Parazynski arrived as far from the airlock as any spaceman has ever been, he described the damaged frayed wires as a "hairball." It became obvious that he had to cut wires, one of the most risky parts of the plan.
He first installed one of the "cuff links" to stabilize the blanket. Then he cut a hinge wire, and then a guide wire. Then the guide wire had to be retracted into a box. Ms. Contella said this was one time she held her breath because there was no video feed in Mission Control--she had to rely on Doug Wheelock, who was stationed at the box, to give a verbal report.
After the wire was retracted, Parazynski cut above the snag. He retrieved some of the pieces of the "hairball" for later inspection, and crimped the others. Then he installed the other 4 cufflinks, and headed back to the airlock.
I watached with fascination as Parzynski threaded the bulky wire through the grommets on the array blanket. The wire curled and snaked around and bounced off the blanket. I could hardly imagine doing that detailed work wearing those clumsy gloves! The blanket made an accordian-like motion, folding and unfolding and also billowing away and then coming back at Parazynski. He held it at bay with his trusty "hockey stick." He punched the "needle" end through and tugged on it to be sure it held. I had just read the newspaper article about the big annual quilting convention here in Houston, and thought that this solar "quilting" job should qualify for some sort of prize.
Parazynski did get a prize for his work: the team offered the former Olympic athelete a "Gold Medal" for Spacewalking. When asked if this spacewalk rated in the top ten of all time, Ms. Contella said that during her 12 years as an EVA officer, it was certainly her number one.
During the airlock ingress, a pair of needle-nose pliers in their book-like caddy, got away. Flight Director Derek Hassmann said the trajectory did not appear to pose a recontact risk to the station.
While the spacewalkers were in the airlock, the array was successfully extended. Mr. Suffredini said that despite the patchwork cufflinks on the array, "our baby is still beautiful to us." He said it was producing 217 amps, but was still "shunted," meaning that power was not flowing from the array to the station systems. Before they "unshunt" it, the flight team wants to do a few more tests to make sure there are no shorts caused by the damaged area. The array is structurally sound now, and can be rotated to track the sun. However, the power is not currently needed. The team fully expects to certify the array to be good through 2015, the expected lifetime of the station.
More Spacewalks Coming Soon
ISS program manager Mike Suffredini said, "The pace [of the assembly] is not going to slow down." He said EVA 5, the one that had originally been scheduled for this weekend, was now on tap for Friday, November 9. This spacewalk by Station Commander Peggy Whitson and Expedition crewmember Dan Tani, will get the PMA ready to be moved. The PMA will be moved on November 12 and attached to Harmony. Then on November 14, the stack of PMA and Harmony will be moved to the front of Destiny. More spacewalks are planned on November 20 and 24 to complete the activation of the Harmony module. This work needs to be completed before the shuttle arrives with the new Columbus module, currently scheduled for December 6. That date may be moved later, but Mr. Suffredini said that the station crew had made up some time in other areas so that it is still possible the launch date may not slip.
The starboard rotary joint (SARJ) repair is not scheduled yet. The spacewalk inspection that was preempted for the P6 repair will probably not be done. Instead, the ground team will analyze the samples the shuttle is bringing down next Wednesday and test some methods of removing this grit on a future space walk. The program has to find "up mass" on one of the future flights as well once they determine if parts need to be replaced. Mr. Suffridini expects this work may take more than one spacewalk.
This spacewalk was an amazing success for the crew, the flight team, the international partners (the Canadians and Russians were especially thanked for contributing hardware, expertise, and crew time), and for everyone who dreams of one day living in space. We have proven that humans can solve the problems of a space utility and do complicated repairs with little preparation time. The knowledge and experience gained through this mission is ours to keep and apply to future activities in space.
Congratulations to the crew and flight control teams for a job fantastically done!
Posted by m_dyson at November 3, 2007 04:35 PM