They spent much of this week preparing themselves and their gear, and they activated a new laboratory super deep-freezer.
Astronauts Jeff Williams and Thomas Reiter will leave the station's Quest airlock hatch at 9:55 a.m. EDT Thursday, Aug. 3, for a spacewalk that is scheduled for six hours, 20 minutes. Station Commander Pavel Vinogradov will serve as the spacewalk choreographer from inside the complex.
Williams and Reiter are both experienced spacewalkers. They will install a device to measure the electrical field around the station's exterior; replace a rotary joint motor controller and a computer for a radiator on the station's truss; deploy two experiments that expose samples of various materials to space for extended periods; and install various other hardware on the station.
To get ready, the crew prepared spacesuits and tools, conducted a dry run of egress and ingress procedures, and moved the station's Canadarm2 robotic arm into position. The arm's cameras will provide television views of the spacewalk.
This week the crew also began operations of the new Minus Eighty-degree Laboratory Freezer for ISS. The equipment can reach temperatures as low as minus 112 degrees Fahrenheit. Provided by the European Space Agency, the freezer was delivered on shuttle mission STS-121 earlier this month and is installed in the Destiny laboratory. It has 300 liters (about 79 gallons) of freezing and storage capacity in four compartments for experiment samples to preserve them for return to Earth.
On Tuesday, Russian flight controllers fired thrusters on the Progress supply ship docked to the aft end of the station to boost the station's altitude. They raised the complex to an orbit of 219 by 203 statute miles. The adjustment optimizes conditions for a docking by the Space Shuttle Atlantis, targeted for a launch window that begins Aug. 27, and by the station's next crew, Expedition 14, set for launch in mid-September on a Russian Soyuz rocket.