SUBMITTED BY ARTHUR N1ORC - AMSAT A/C #31468

*Russian Navigation Computer Passes Test*

Flight controllers in Moscow conducted a test to check the ability of the Russian segment’s terminal computer to fire thrusters and maintain attitude of the International Space Station.

Russian and U.S. mission managers gave the computer a passing grade. U.S. managers then gave the STS-117 crew approval to undock space shuttle Atlantis on Tuesday.

The Russian navigation computers provide one method of backup attitude control and orbital altitude adjustments. The station’s control moment gyroscopes are the complex’s primary attitude control system. The shuttle’s propulsion system also provides a backup attitude control system for the complex.

*STS-117 Stay at Station Coming to a Close*

STS-117’s stay at the International Space Station is winding down. Atlantis is scheduled to undock from the station at 10:42 a.m. EDT Tuesday, leaving the station with a new truss segment and crew member.

Expedition 15 welcomed its visitors onto the station June 10 shortly after space shuttle Atlantis docked. A few hours later Astronaut Clayton Anderson replaced Suni Williams as a flight engineer on the Expedition 15 crew. Williams will return to Earth with STS-117, wrapping up a six-month-plus stay in space during which she became the new record holder for the longest single spaceflight by a woman.

On June 11, the STS-117 crew installed the Starboard 3 and 4 truss segment onto the station. The visiting astronauts conducted four spacewalks to activate the new truss and its solar arrays. The STS-117 crew also assisted with the retraction of the Port 6 (PS) truss array. The P6 will be relocated from atop the station to the end of the Port 5 truss by a future shuttle crew.

The S3/S4 is 45 feet long and weighs 35,678 pounds. Its solar arrays 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.

+ Read more about Expedition 15 http://www.nasa.gov/mission_pages/station/expeditions/expedition15/index.html + View crew daily timelines http://www.nasa.gov/mission_pages/station/timelines/index.html