NASA STS-127 Report #22 Sunday, July 26, 2009 – 4:30 a.m. CDT

Mission Control Center, Houston, Texas

HOUSTON – After a day of rest, the 13 astronauts and cosmonauts on the International Space Station will shift back into high gear for robotic operations and spacewalk preparations.

The crew’s Sunday wake-up music was composer George Frederic Handel’s “Dixit Dominus.” The excerpt was uplinked for Canadian Space Agency astronaut Julie Payette at 3:03 a.m. CDT.

Overnight, flight controllers continued to manually operate the Carbon Dioxide Removal Assembly (CDRA), which shares responsibility for revitalizing the station’s atmosphere with a similar Russian system. They’re keeping the atmosphere at normal levels, but are refining the remote-control procedures.

The U.S. CDRA has two “beds” that alternately collect or expel the gas byproduct of human breathing from the station. The primary heater tripped a circuit breaker Saturday afternoon, and since then the ground team has been manually operating the backup heater. Engineers are continuing to analyze data on the primary heater. A second CDRA will be delivered to the station on STS-128 as part of the Air Revitalization System rack.

Endeavour Commander Mark Polansky, Pilot Mark Hurley and Payette, along with Expedition 20 Flight Engineer Tim Kopra, will return a Japanese payload carrier to the shuttle’s cargo bay today using the shuttle and station robotic arms.

Spacewalkers Chris Cassidy and Tom Marshburn, meanwhile, will ready their spacesuits and tools, and check procedures for Monday’s fifth and final STS-127 spacewalk. The six new batteries installed on the Port 6 truss during the past two spacewalks accepted their initial charge and have been integrated into the station’s power grid.

The station crew is scheduled to begin its sleep period at 6:03 p.m., followed 30 minutes later by the shuttle crew.

The next mission status report will be issued after crew wake or earlier if warranted.