May 12, 2006

Katherine Trinidad
Headquarters, Washington
(202) 358-3749

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



Expedition 13 Commander Pavel Vinogradov and Flight Engineer Jeff
Williams focused this week on science experiments, maintenance tasks
and unpacking cargo on the International Space Station.

Using the microgravity science glovebox, Williams began the second of
three sessions Wednesday of the Pore Formation and Mobility
Investigation experiment. This experiment studies bubbling that
occurs in weightlessness as liquids cool and solidify.

Williams will begin his first Saturday Science activity this weekend
with the Cellular Biotechnology Operations Support Systems Fluid
Dynamics Investigation. This is a series of experiments to improve
fluid mixing techniques and to control bubble distribution for cell
culture in orbit.

On May 4, ISS Progress 21 engines were used to reboost the station.
Afterward, an error message indicated the Zvezda Service Module
computers couldn’t command the Progress engines to reconfigure for
normal operations. The reboost was not affected. Engineers have
determined the most likely cause of the message was a software error,
which will be corrected. Meanwhile, a procedural change will allow
the Progress thrusters to be used. Vinogradov and Williams continued
to unpack supplies from that cargo vehicle.

Last week, engineers detected a small reduction of nitrogen pressure
in the liquids unit of the oxygen-generating Elektron. To isolate the
source of the leak, Russian flight controllers asked Vinogradov to
turn off the machine. They have identified the small leak and plan to
operate the Elektron as needed. A spare liquids unit is onboard.

The Elektron will remain deactivated until after a June 1 spacewalk.
Engineers originally had planned to turn it off next week to
reconfigure ventilation lines and to install a new hydrogen vent
before the extravehicular activity. Meanwhile, oxygen from tanks in
the ISS Progress 20 cargo vehicle is being added to the station’s

On Thursday, Williams practiced using the station’s robotic arm. He
and Vinogradov spoke Wednesday with reporters from the StarDate
syndicated Radio Network and WISN-TV of Milwaukee.

The next station status report will be issued on Friday, May 19, or
earlier if events warrant. For more about the crew’s activities and
station sighting opportunities, visit:

Il comandante della spedizione 13 Pavel Vinogradov nella biografia che ho trovato su internet viene indicato come cosmonauta di terza classe:sapete cosa significa?quali mansioni/qualità ha in più o in meno rispetto ad uno di prima o seconda classe?Grazie in anticipo a chi mi risponderà.