Commander Michael Lopez-Alegria and Flight Engineer Suni Williams completed the last of the internal assembly tasks for the startup later this year of the new Oxygen Generation System (OGS) in the Destiny laboratory. The astronauts installed sound-deadening equipment and an electrical cable and reconnected a wastewater hose for the hardware that was delivered last summer on space shuttle mission STS-121. OGS, which will be required once the station crew size expands to six people, is slated for activation during Expedition 15. It will function initially as another backup to the Russian Elektron system.
Flight Engineer Mikhail Tyurin spent time this week in maintenance of systems in the Russian segment of the station and in long-range preparations for arrival of the first of the European Space Agency’s cargo-carrying Automated Transfer Vehicles. Tyurin set up equipment in the Zvezda module for a ground-operated test of the satellite navigation system to be used during autonomous docking of the ATV to the Zvezda module’s aft port. He also pressurized and stowed a spare liquids unit for the Elektron, which supplies oxygen for the station's crew, and installed a new liquid crystal display for the TORU system, the manual docking system for Progress unpiloted supply ships.
Expedition 14 crew members used their brains this week for scientific experiments. Lopez-Alegria and Williams conducted another session with the Anomalous Long-Term Effects in Astronauts' Central Nervous System (ALTEA) experiment. It measures exposure to cosmic radiation.
For 90 minutes, each crew member wore an instrumented helmet containing six different particle detectors which measured radiation exposure, brain electrical activity and visual perception. ALTEA will further understanding of radiation impact on the human central nervous and visual systems, especially the phenomenon of crew members seeing flashes of light while in orbit.
Crew members also tested their hand-eye coordination during the Test of Reaction and Adaptation Capabilities, or TRAC, experiment. TRAC studies the theory that while the brain is adapting to space, it is unable to provide the resources necessary to perform normal motor skills such as hand-eye coordination.
They used a laptop and a joystick to control the position of a cursor, and a reaction time box to measure their response to audio and visual cues. Understanding how the brain adapts to microgravity could lead to improved procedures for activities requiring precise motor skills.
U.S. and Russian station officials reached agreement this week on a plan to have the Expedition 14 crew relocate the Soyuz TMA-9 craft on March 29 from the Earth-facing port of the Zarya module to the aft port of the Zvezda module. This will alleviate the next station resident crew from having to perform the maneuver to reach Zarya as its final destination for the Expedition 15 increment.
The ISS Progress 23 cargo ship currently docked to Zvezda, will be cast off on March 27 to make room for the Soyuz.
Both sides also agreed this week to conduct a reboost of the station on March 15 using the Progress 23 engines to place the station at the correct altitude for the launch of the Expedition 15 crew in the Soyuz TMA-10 capsule on April 7. They will dock to Zarya on April 9. The Expedition 14 crew will now return to Earth on April 20.