Jan. 13, 2006

J.D. Harrington
Headquarters, Washington
(202) 358-5241

James Hartsfield
Johnson Space Center, Houston
(281) 483-5111



This past week, Expedition 12 Commander Bill McArthur and Flight
Engineer Valery Tokarev completed an important upgrade to the
station’s spacewalk preparation systems, and installed the Recharge
Oxygen Orifice Bypass Assembly.

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.

For information about crew activities, future launch dates and station
sighting opportunities on the Web, visit:

For information about NASA and agency programs on the Web, visit:


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