The Liverpool Astronomical Society

Navigation Computers Troubleshooting Efforts Continue

Earlier in the day, International Space Station Program Manager Mike Suffredini told reporters Russian and U.S. flight controllers and engineers are focusing on efforts for recovering the computers and options to maintain attitude control until the problem is resolved.

“I think we’re in good shape,” Suffredini said. “We still have a lot of options to go through to recover these machines. We’ve got a talented group of people to look at attitude control.”

The navigation computers provide backup attitude control and orbital altitude adjustments. For now, the station’s control moment gyroscopes are handling attitude control, with the shuttle’s propulsion system providing backup. The Expedition 15 and STS-117 crews continue to conduct joint operations aboard the International Space Station and Space Shuttle Atlantis.
Throughout the week, the two crews have been activating the Starboard 3 and 4 (S3/S4) truss segment that was attached to the station on Monday.

The STS-117 crew has conducted two spacewalks to prepare the new segment for activation and to retract arrays on the Port 6 (P6) truss. The P6 will be relocated from atop the station to the end of the Port 5 truss by a future shuttle crew. See image below.

The S3/S4, which is 45 feet long and weighs 35,678 pounds, contains a new set of solar arrays that will increase the station’s power-generation capabilities. The S3/S4 also contains a rotary joint that will allow its arrays to track the sun.In addition to a new truss segment, NASA Astronaut Clayton Anderson joined the Expedition 15 crew on Sunday, replacing Flight Engineer Suni Williams. Anderson arrived at the station as a member of Space Shuttle Atlantis’ crew. Atlantis docked to the station on Sunday. Williams spent six months as an Expedition crew member.

STS-117 arrived at the station June 10 and is scheduled to undock June 19.