It was the second of two spacewalks for the Expedition Five crew, the fourth of Korzun's career and the first for Treschev. Today's excursion was the 43rd spacewalk in support of ISS assembly and maintenance and the 18th staged from the station itself. 25 spacewalks at the ISS have originated from visiting space shuttles. While Korzun and Treschev worked outside, Flight Engineer Peggy Whitson tended to station systems and choreographed the spacewalk from inside Zvezda.
Whitson and Korzun conducted a 4 hour, 25 minute spacewalk on August 16 to install six micrometeoroid debris shields on Zvezda.
After a slight delay to track down a small pressure leak across the hatch between Zvezda and the Zarya module, Korzun and Treschev opened the hatch to Pirs at 12:27 a.m. Central time (527 GMT) as the ISS flew over Russia at an altitude of 235 statute miles. They went to work right away, installing a frame on the Zarya as a "parking place" for modular equipment to be temporarily stowed during future ISS assembly spacewalks and hardware on Zarya which will better route tethers for spacewalkers working around the Russian segment of the station.
The two Russian spacewalkers then exchanged trays of experiments in suitcase-like devices on Zvezda for NASDA, the Japanese Space Agency, which measure the effect of the space environment on engineering materials.
With that work accomplished, Korzun and Treschev completed a task left over from the previous spacewalk ten days ago. They replaced an experiment on the outside of Zvezda called Kromka, which measures the amount of residue emitted from the module's jet thruster firings. Deflectors previously installed on Zvezda have significantly reduced the buildup of residue on the hull of the module.
The final job for Korzun and Treschev was the installation of two additional ham radio antennas on Zvezda to enhance amateur radio operations in the future. ISS residents frequently conduct conversations with "hams" back on Earth.
After retrieving their tools, Korzun and Treschev returned to Pirs and closed the hatch at 5:48 a.m. Central time (1048 GMT) to wrap up their excursion.
The next series of spacewalks to be conducted at the ISS is planned for October when two shuttle astronauts, Dave Wolf and Piers Sellers, conduct three excursions from the Quest Airlock on the STS-112 mission aboard Atlantis to help install and activate the S1 (Starboard One) truss segment, further expanding the station's backbone.