Two of three critical computers on the International Space Station were restored this afternoon while astronauts outside the orbiting laboratory repaired a damaged thermal blanket on shuttle Atlantis and successfully retracted a stubborn solar array.
Carpenter Newton reporting for Digital Journal –– Around 5:00 p.m. EDT today, International Space Station Commander Fyodor Yurchikhin and flight engineer Oleg Kotov used a jumper cable to bypass a power supply switch to bring two of three computers that control navigation and oxygen systems on the space station back to life after a two day absence.
The three computers suffered a failure on Wednesday and after many hours worth of troubleshooting, Russian engineers were stumped as to what was causing the glitch.
NASA suspected that a truss segment, newly installed on Monday, might have been causing ‘noise’ that the computers were sensitive to, thus causing them to shutdown and not reboot.
The three computers normally operate in tandem, meaning that when all three are on, they sync together. When one gets out of sync, the other two remain synced and active -- when they all fall out of sync, the entire system gets restarted without any hiccups. During this glitch, the system wasn’t restarting at all.
On today’s spacewalk, astronaut James Reilly disconnected a power cable on the new S3/S4 truss, but apparently that had no effect on bringing the computers back up. “They just had good fortune over there on the computers,” CAPCOM Megan McArthur radioed the shuttle crew from Mission Control.
The computers will be under close watch over the next several hours to make sure they continue to perform normally.
Had the computers have not been restored by the time space shuttle Atlantis needed to undock from the ISS, astronauts would not have been in any danger aboard the ISS. Russia had already begun to move up plans to deliver a cargo ship full of computer supplies in July, and the ISS had over 50 days of oxygen supplies.
Until engineers determine the computers are stable, Atlantis’ departing date remains up in the air.
Spacewalk Three A Complete Success; Atlantis Repaired, Solar Array Folded
The third of four scheduled spacewalks for STS-117 started this afternoon at 1:24 p.m. EDT as astronauts James Reilly and Danny Olivas switched their spacesuits to internal battery power and exited the space station. Olivas rode the shuttle’s robotic arm to the Orbital Maneuvering System pod and repaired a damaged thermal blanket using surgical staples.
Danny Olivas staples the damaged thermal blanket on Atlantis. Photo: NASA TV
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Olivas patted the blanket into place with his gloved hand, then stapled the blanket down with two rows of the stainless steel staples. As an additional precaution, he also used stainless steel thread to pin the blanket to an adjacent blanket -- essentially sewing two blankets together.
While Olivas worked his magic on Atlantis, Reilly was busy installing a hydrogen vent on the ISS.
Nearly five hours into the walk, both astronauts then turned attention to a solar array the crew had been attempting to fold for three days. Using tools wrapped in insulating Kapton tape, Reilly and Olivas coaxed the solar array into full fold, then inspected the blanket box to make sure it was in good configuration.
Today’s spacewalk lasted 7 hours, 58 minutes, about 90 minutes longer than anticipated. Today’s numbers bring total STS-117 EVA time to 21 hours, 29 minutes.
Sunita Williams Sets New Record
Sunita Williams. Photo: NASA
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At 188 days in space, Sunita Williams becomes the female with the most experience in orbit, besting previous record holder Shannon Lucid. Williams will return to Earth aboard Atlantis next Thursday after being replaced on the ISS by Clayton Anderson.
