Each astronaut will be wearing an Extravehicular Mobility Unit (EMU) spacesuit, which allows mobility, life support, communications, and environmental protection when performing extra-vehicular activity (EVA) from the ISS (and from the Shuttle) while in Earth orbit.

The second spacewalk (EVA-7) originates from the Quest Joint Airlock Module, like the first spacewalk (EVA-6), which took 7 hours, 55 minutes to complete. The Quest is the primary airlock for the space station, allowing both American and Russian spacesuits to be stored in the Equipment Lock and for both American and Russian spacewalkers to exit the ISS from the Crew Lock.

ISS commander López-Alegría and ISS flight engineer Williams will first reconfigure the second of two cooling loops serving the Destiny Laboratory Module so that the lab can transfer from the temporary power and cooling system to the permanent power and cooling system. Then, López-Alegría will reconfigure the fluid loop connections so that the second pair of fluid lines of the temporary system is connected to the Z1 panel (in case the temporary system is ever needed again).

Williams will next reconfigure electrical connections. Later, both astronauts will watch ground controllers retract the aft radiator located on the P6 truss (part of the Integrated Truss Structure, which forms the backbone of the ISS). Upon successful completion of the retraction, the two spacewalking astronauts will install another set of six cable cinches and two winch bars to secure the radiator and install the shroud.

López-Alegría will then move to the end of the Pressurized Mating Adapter-1 (PMA-1) to remove one bolt to release a sunshade from the Node Multiplexer-Demultiplexer (MDM), a data relay system. The removal of the sunshade will allow the MDM to receive more warmth from the Sun now that the station has reoriented itself with Destiny positioned in the forward direction of the station’s orbit. The sunshade will be jettisoned away from the station by López-Alegría.

Williams will next take tools and cables to the forward end of Destiny where she and López-Alegría will finish the installation of the SSPTS (Station-to-Shuttle Power Transfer System) cables.

If time permits, they will also photograph a connector on the end of the Pressurized Mating Adapter-2 (PMA-2) because ground controllers suspect that the connector is causing static in communications because of debris or corrosion around it.

The third spacewalk (EVA-9) in the series of three (within a nine-day period) will occur on Thursday, February 8, 2007.

Additional information about the Expedition 14 crew aboard the International Space Station is found at: http://www.nasa.gov/mission_pages/station/main/index.html.

To track the flight of the ISS, please go to: http://spaceflight.nasa.gov/realdata/tracking/.

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