The International Space Station's Expedition 9 crewmembers are now past the halfway point of their six-month mission. This week, they prepared for a third spacewalk and joined the world in observing the 35th anniversary of the first landing of humans on the moon.

July 19 was the midpoint of the flight for ISS Commander Gennady Padalka and Flight Engineer Mike Fincke, who launched Apr. 19 and are targeted to return Oct. 19. On Monday Fincke spoke with Charles Gibson of ABC-TV's "Good Morning, America" about the birth of his daughter, Tarali, in June while he was in space. Fincke's wife and children joined the discussion from Houston.

This week the crew continued packing unneeded equipment and trash in the Progress vehicle, scheduled to undock July 30. Undocking the Progress from Zvezda's aft docking port will clear the area for the next spacewalk, targeted for Aug. 3.

Wearing Russian spacesuits and exiting from the Pirs Docking Compartment, Padalka and Fincke are to install retroreflectors and communications equipment needed for the docking of the Automated Transfer Vehicle, a European Space Agency cargo spacecraft scheduled to make its first flight next year. Thursday, Padalka and Fincke maneuvered the Station's Canadarm2 into position so its cameras can view the spacewalk, and Friday they wrapped up a thorough review of the spacewalk timeline with specialists in Moscow.

Fincke and Padalka also continued their support this week of an experiment that looks at the interactions between the crew and the ground teams. This experiment involves a questionnaire on a laptop computer, which the crew and members of their ground support team complete once a week.

The data is being used to examine issues involving tension, cohesion and leadership roles in both the crewmembers and their support team. The information gained will lead to improved training and in-flight support of future space crews.

As part of Fincke's Saturday Afternoon Science, he conducted another session of the Educational Payload Operations or EPO. This EPO activity demonstrated what crewmembers can observe about pollution and the environmental problems on Earth. Fincke showed the window where he observes the Earth, and described what types of pollution can be seen -- such as air pollution in urban areas, smoke from wildfires, deforestation and strip mining.

The activity was videotaped and will be used later in classrooms and NASA educational products. EPO is an education payload designed to support the NASA Mission to inspire the next generation of explorers.

Meanwhile, flight controllers in Houston are continuing to investigate why two U.S. spacesuits are not providing the proper cooling. This week, Fincke conducted troubleshooting of a motor in the water pump of one of the spacesuits as engineers on the ground monitored. An analysis of photos and video from that work is underway. Two spare water pumps will be launched in the next Progress supply ship, due to lift off Aug. 11 from the Baikonur Cosmodrome in Kazakhstan.

The failure of a computer on the Station's inactive starboard thermal radiator on Monday has no significant impact on current operations. The radiator is not in use in the present Station configuration, although the computer had assisted flight controllers with monitoring of temperatures and pressures of the unused equipment. The radiator is not scheduled to be used until several missions after the Space Shuttle's return to flight.

Tuesday, Padalka and Fincke celebrated the anniversary of the Apollo 11 moon landing and discussed the past, present and future of space exploration -- and the role to be played by the International Space Station in future exploration -- during in an interview with CBS News.