The assembly will conserve station oxygen during spacewalk preparations when the space shuttle is docked to the complex. It allows the crew to breathe oxygen from the shuttle rather than use oxygen from station tanks, as they prepare for the spacewalk. The crew must breathe pure oxygen for an extended period before beginning a spacewalk to prevent decompression sickness. The new system will be used during the next shuttle mission.
McArthur wore customized Lycra cycling tights for a session of the Foot/Ground Reaction Forces during Spaceflight (FOOT) experiment. FOOT investigates the differences between use of the body's lower extremities on Earth and in space. McArthur wore the instrumented garb to measure joint angles, muscle activity, and forces on his feet during daily activities.
On Thursday, McArthur maneuvered the station's Canadarm2 robotic arm to provide TV images of an interface umbilical assembly. The assembly houses a contingency cable cutter for a line that provides power, data and video to the station's Mobile Transporter. The transporter is a rail car that travels along the station's truss. A second identical assembly on the other side of the transporter inadvertently cut a backup cable for the system last month. The camera views allowed engineers to survey the remaining intact assembly and cable. The crew will install a safety bolt in the intact system during a Feb. 2 spacewalk.
McArthur also maneuvered the arm, positioning cameras to survey a station port seal where shuttle cargo modules dock. Engineers used the view to inspect the Common Berthing Mechanism on the Unity module for possible debris, and then the arm was positioned to provide views of the upcoming spacewalk.
The Elektron oxygen-generation system was activated by Tokarev after being deliberately shut off in mid-December. The Elektron was turned off to use the oxygen supplies aboard the first of two Progress cargo carriers docked to the station. Tokarev also worked on a number of Russian science projects throughout the week.
McArthur answered student questions from Peterson Elementary School in his hometown of Red Springs, N.C. and from St. Albert the Great School in North Royalton, Ohio via ham radio. He also talked with high school students in Hiroshima, Japan.