April 21, 2006

Katherine Trinidad
Headquarters, Washington
(202) 358-7239

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



The Expedition 13 crew this week focused on experiments, maintenance
and preparations for the arrival of two and a half tons of food,
supplies and equipment.

Expedition 13 Commander Pavel Vinogradov and Flight Engineer and NASA
Science Officer Jeff Williams also had time set aside each day to
continue to become familiar with their orbiting home.

In scientific work, Williams operated the Capillary Flow Experiment,
which uses liquid silicone to study how fluids move in a microgravity
environment. This portion of the experiment examined the interface
between the liquid and the solid surface of the container. The
results could be used by designers of systems for future spacecraft.

Williams also set up and activated cameras that will be remotely
operated by middle school students to take photos of Earth through
the station window. Called the Earth Knowledge Acquired by Middle
School Students (EarthKAM) experiment, it allows students to study
the Earth and then control a special digital camera mounted on the
station. They photograph coastlines, mountain ranges and other
geographic items of interest from the unique vantage point of space.
More than 112 schools from eight countries have signed up for this
session of the experiment. This is the 22nd time the experiment has
been performed aboard the station.

Williams and Vinogradov completed the first of three sessions with the
Renal Stone experiment, a study of whether potassium citrate can be
used to reduce the risk of kidney stone formation. Astronauts have an
increased risk of developing kidney stones because urine calcium
levels are typically much higher in space. The crew recorded all
consumed food and drinks and collected urine samples for later return
to Earth. An understanding of the crew’s diet during the urine
collection timeframes will help researchers determine if the excess
calcium in the urine is due to diet or a response to the microgravity

The Expedition 13 crew also spent several hours practicing the use of
a manual docking system for next week’s arrival of the ISS Progress
21 cargo vehicle. The computer-based training will ensure they’re
ready to take control of the Progress if the automated system does
not work properly. The 21st Progress to visit the station is
scheduled to launch from the Baikonur Cosmodrome in Kazakhstan at
12:03 p.m. EDT Monday, and dock with the space station at 1:40 p.m.
EDT Wednesday. NASA TV will provide live coverage of the docking
beginning at 1 p.m. EDT Wednesday.

A planned reboost of the station was aborted before any engines were
fired this week when downlink telemetry showed one of two sunshade
covers on the Zvezda Service Module thrusters was not fully open. The
station’s onboard software detected that the cover was not properly
opened and did not ignite the thrusters. The firing was designed to
test two thrusters that have not been used since Zvezda docked to the
station in July 2000. Zvezda has several other thrusters that could
be used if needed. Engineers at the Russian Mission Control Center in
Korolev are reviewing data and considering whether additional tests
are required.

Friday the crew talked with experts in Mission Control, Houston, about
an electrical repair procedure planned for Monday. The pair will
replace a failed type of circuit breaker called a Remote Power
Control Module (RPCM) in the Destiny Laboratory. The RPCM failed
during the last crew’s stay aboard the station, and power for several
systems has been routed by an alternate path until it is replaced.

Vinogradov and Williams will remain in orbit for six months. During
that time, they expect to welcome two space shuttles and perform two
spacewalks. European Space Agency astronaut Thomas Reiter will join
the Expedition 13 crew when the Space Shuttle Discovery arrives on
the STS-121 mission, targeted for launch no earlier than July 1.
Reiter will increase the station crew size to three for the first
time since May 2003 when it was reduced to conserve supplies
following the Columbia accident. The payload operations team at
NASA’s Marshall Space Flight Center, Huntsville, Ala., coordinates
U.S. science activities on the station.

The next status report will be issued Monday, April 24, following the
launch of the Progress resupply craft. For EarthKam information and
images, visit:

Information on the crew’s activities aboard the space station, future
launch dates, and station sighting opportunities are available at:


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