HOUSTON — NASA managers will discuss updated plans for two International Space Station spacewalks during a news briefing at 3 p.m. CDT on Monday, Aug. 2. The briefing replaces one originally scheduled for Tuesday.

The news conference from NASA’s Johnson Space Center in Houston will air live on NASA Television and the agency’s website. Journalists may ask questions from participating NASA locations.

The briefers are: – Michael Suffredini, manager, International Space Station Program – Courtenay McMillan, Expedition 24 spacewalk flight director

Expedition 24 Flight Engineers Doug Wheelock and Tracy Caldwell Dyson are scheduled to perform two spacewalks. The two NASA astronauts will replace an ammonia coolant pump that failed July 31.

Engineers and flight controllers continue to review data on the failure, which resulted in the loss of one of two cooling loops aboard the station. This caused a significant power down and required adjustments to provide the maximum redundancy possible for station systems. The systems are stable, and the six crew members aboard are not in any danger.

Wheelock and Caldwell Dyson originally were scheduled to perform a spacewalk to outfit the Russian Zarya module for future robotics work and prepare the station for the installation of a new U.S. permanent multipurpose module. However, because of the importance of restoring redundancy to the station’s cooling and power systems, Thursday’s spacewalk will be dedicated to the pump module replacement. Another spacewalk will be scheduled a few days later to complete the repairs.

NASA TV coverage of the 15th U.S. spacewalk from the station will begin at 5 a.m. on Thursday, Aug. 5. Wheelock and Caldwell Dyson are expected to begin the spacewalk from the Quest airlock at 5:55 a.m. It will be Wheelock’s fourth spacewalk and Caldwell Dyson’s first.

For NASA TV streaming video, schedules and downlink information, visit: http://www.nasa.gov/ntv

For more information about the station and the Expedition 24 crew, visit: http://www.nasa.gov/station