The crew began the week by bringing the Active Rack Isolation System back to life after installing a new shock absorber in the rack. One of the eight pushrods that was not operating correctly was replaced by the crew. The system works to dampen out the vibrations generated by crews' movement throughout the station. Those vibrations could affect the delicate science experiments located inside the rack. Air and water samples were taken from the Advanced Astroculture experiment inside the US Destiny laboratory. The samples will be brought back to Earth for scientists to study. Scientists hope to determine what nutrients and conditions are necessary for plants to grow in microgravity.
The Earthkam experiment was activated once again this week. The crew set up a digital camera in the window of Destiny, enabling middle school students on the ground to remotely take pictures of the Earth's geographical features from a vantage point 240 statue miles high.
To prepare for the Earthkam activation, the station's robotic arm was moved Tuesday so it would not block the view of Earth from the Destiny lab. The crew could not release the brakes to begin the move using the arm's primary avionics system. The secondary avionics system operated normally, however, and was used to perform the move. The specific cause of the problem with the primary avionics system is still being investigated.
Thursday, the crew put the arm through a practice run of the movements it will make during the next shuttle mission to the station, STS-110 in April. The arm will be used to attach the next major station component, the S0 truss. On Thursday, ground controllers also sent up tests for the primary and secondary computer workstations used to operate the arm. The secondary workstation was not able to boot up during the test, and engineers are evaluating it. When the workstation difficulties were encountered, the arm was left in a safe parked position while engineers study the problem.