Three hours later, Russian flight controllers commanded its engines to fire to put it on course to plunge into the atmosphere and burn up over the Pacific Ocean. The cargo ship had been docked to the station since September 2005.

The Progress 20 spacecraft, which arrived in December 2005, remains attached to the Pirs docking compartment.

Also last week, McArthur replaced the trace-contaminant control system in the Destiny laboratory. The system removes impurities from the cabin air. It had been experiencing slightly degraded performance over the past few months, but after the repair it is operating normally, NASA said in a statement.

On Monday, McArthur will attempt to reconnect and activate the major constituent analyzer in Destiny. It is a mass spectrometer that measures compounds in the station's atmosphere. Efforts to activate the system two weeks ago were unsuccessful due to what is thought to be damaged or bent electrical connectors.

When the device is activated, mission controllers can resume plans for what they are calling a crew campout in the Quest airlock later this month. The purpose is to test streamlined spacewalk preparation procedures. The new procedures will shorten the time needed to cleanse nitrogen from spacewalkers' bodies to prevent decompression sickness. For the test, McArthur and Tokarev will spend the night in Quest at a reduced pressure, lessening the time they need to breathe pure oxygen in advance of a spacewalk.

Astronauts aboard the STS-115 shuttle mission, currently planned for August, also will use the campout technique for spacewalks. If McArthur can activate the major constituent analyzer successfully, the campout test will be scheduled around March 23.

McArthur continued preparations for the arrival of the next shuttle mission. Discovery is targeted for launch no earlier than May on that flight, designated STS-121. McArthur has been placing unneeded items in racks earmarked for return to Earth aboard Discovery.

The two crew members soon will begin preparations for a short trip from the station. Managers tentatively have agreed on March 20 for the crew to relocate their Soyuz TMA-7 spacecraft from the Earth-facing docking port of the Zarya module to the aft docking port of Zvezda.

McArthur and Tokarev will undock from Zarya and conduct a 37-minute flight to re-dock at Zvezda. The move will clear the Zarya port for the April 1 arrival of the Soyuz carrying the next station crew, Expedition 13.

Expedition 13 is commanded by Pavel Vinogradov. Jeff Williams is NASA Flight Engineer. Brazilian astronaut Marcos Pontes also will fly to the station for a short stay, returning to Earth a week later with McArthur and Tokarev.

This coming week, McArthur will brush up on his robotics skills, operating the Canadarm2 for engineering tests. Flight controllers in Houston also will operate the arm remotely to survey one of two integrated umbilical assembly mechanisms on the mobile transporter rail car. The assembly's cutting blade system malfunctioned Dec. 16, severing one of two umbilicals on the transporter.

The agenda for the second of three spacewalks planned for Discovery's ISS rendezvous includes replacing the assembly. Controllers also will use the arm to survey a vent port for the carbon dioxide removal assembly on the Destiny laboratory.

Related Links
ISS

Memory Foam Mattress Review

SPACE MEDIA NETWORK PROMOTIONS Solar Energy Solutions Tempur-Pedic Mattress Comparison ... Newsletters :: SpaceDaily :: SpaceWar :: TerraDaily :: Energy Daily XML Feeds :: Space News :: Earth News :: War News :: Solar Energy News