Foale and Kaleri will spend most of the weekend in a smaller portion of the station than usual, primarily the Zvezda living quarters module. Foale and Kaleri floated into the Zvezda shortly after 2 p.m. Central time, closing several hatches behind them. Flight controllers will monitor air pressure in the station modules during that time to verify that the pressure aboard is stable and to gather baseline data on normal air pressure fluctuations in the complex.
For the data gathering session, the Station cabin has been divided into four sections. The one where the crew is staying includes Zvezda, the Soyuz spacecraft, the Pirs docking compartment and the Progress cargo vehicle. Another section includes the Unity connecting node and the Quest airlock. A third section is the Zarya control module and Pressurized Mating Adapter 1. The fourth section is the Destiny laboratory.
All of the hatches will be reopened Sunday afternoon.
On Jan. 11, Foale tracked down the probable cause of a slight pressure decay that had been detected aboard the station since late December. Foale found a leaking flex hose that is part of a system that prevents fogging within Destiny's window. The hose was removed and the leak stopped. Engineers are evaluating plans to launch a replacement hose on the next Progress supply vehicle on Jan. 29.
Earlier this week, Kaleri replaced a liquid separation unit for the Russian Elektron oxygen generation system, restoring that system to full function. The week also included a number of science and medical experiment activities for the crew. Kaleri performed an assessment of the effects of weightlessness on the inner ear using a special Russian suit and collected air samples as part of another Russian program designed to help assess the microbial environment aboard the ISS.
Foale conducted his second session with the Foot/Ground Reaction Forces During Spaceflight (FOOT) experiment, gathering several hours of additional data. For the experiment, Foale dons a special pair of instrumented leggings that allow researchers to measure forces on the feet, joint angles and muscle activity. Foale also participated in a Hand Posture Analyzer investigation, which uses a special glove to assess the changes in how humans reach, grasp, manipulate and transport objects during long periods in weightlessness.