Mission Control told Space Shuttle Endeavour's crew Wednesday that STS-118's fourth spacewalk will be moved to Saturday. The decision gives the STS-118 and Expedition 15 crew members an extra day to prepare for the spacewalk, which was added to the mission after the STS-118 crew arrived at the station

http://www.amsat.org/amsat/archive/sarex/48hour/msg00956.html

Preparations for a possible spacewalk to repair a small ding in Endeavour's thermal protection system tiles will occupy a considerable part of today for Commander Scott Kelly and Mission Specialists Rick Mastracchio, Dave Williams and Tracy Caldwell.

Mission managers have not decided that a repair spacewalk will be needed. But to prepare for that possibility, the crew members will begin to get ready to do the repair, should managers determine that is necessary.

The managers did decide to move the flight's fourth spacewalk from Friday to Saturday. If the repair isn't done, that spacewalk will see installation of two antennas and removal of one, installation of a stowage stand for the shuttle's orbiter boom sensor system and other tasks.

Flight controllers decided just before 3 p.m. EDT to end today's spacewalk early because of damage to the outer layer of one of Mission Specialist Rick Mastracchio's gloves. Even though there is no threat to his safety, the decision was made as a precaution.

His spacewalking partner, Clay Anderson, is finishing with the retrieval of a transponder on the Port 6 truss. Mastracchio will remain in the Quest airlock until Anderson returns to the airlock following finishing that task.

Retrieval of the two MISSE experiments will be deferred to a future spacewalk. The experiments were deployed in August 2006 and will be returned to Earth for analysis.

The third spacewalk of Endeavour's visit to the International Space Station will help lay groundwork for relocation of the Port 6 truss, upgrade a station voice communications system and retrieve materials experiments.

Endeavour Mission Specialist Rick Mastracchio and station Flight Engineer Clay Anderson are scheduled to begin the 6½-hour spacewalk at 10:01 a.m. CDT.

The Endeavour crew, Commander Scott Kelly, Pilot Charles Hobaugh, and Mission Specialists Tracy Caldwell, Mastracchio, Dave Williams, Barbara Morgan and Alvin Drew, and station crew members, Commander Fyodor Yurchikhin, Flight Engineer Oleg Kotov and Anderson, were awakened for spacewalk 3 day at 5:07 a.m. CDT by "Good Morning World." It was written and performed by Morgan's son Adam.

ISS's robotic arm, Orbital Boom Sensor System and Endeavour's robotic armImage above: The International Space Station's robotic arm prepares to hand off the Orbiter Boom Sensor System (OBSS) to shuttle Endeavour's robotic arm. Image credit: NASA TV
TO VIEW IMAGE GO TO: http://www.nasa.gov/mission_pages/station/main/index.html

Zarya, the International Space Station's first component to go into space, passed the 50,000th orbit mark at 11:17 a.m. EDT today. Zarya, which is Russian for "Sunrise", was funded by the United States and built by Russia. It launched atop a Proton rocket from Baikonur Cosmodrome in Kazakhstan on Nov. 20, 1998.

A third external stowage platform (ESP) will be installed on the International Space Station today. This time it will be done by crew members using robotic arms of the shuttle Endeavour and the station.

Both ESPs now on the station, one on the U.S. laboratory Destiny and the other on the Quest airlock, were attached during spacewalks.

The Endeavour crew, Commander Scott Kelly, Pilot Charles Hobaugh, and Mission Specialists Tracy Caldwell, Rick Mastracchio, Dave Williams, Barbara Morgan and Alvin Drew, and station crew members, Commander Fyodor Yurchikhin and Flight Engineers Oleg Kotov and Clay Anderson, were awakened at 5:07 a.m. CDT by "Happy Birthday Tracy," performed by Caldwell's nieces and nephews, in recognition of the day's significance.

An International Space Station / STS-118 ARISS school contact has been planned with children in the McCall-Donnelly School District in McCall, Idaho, USA on 16 Aug. The event is scheduled to begin at approximately 15:14 UTC.

The contact will be a telebridge between stations NA1SS and VK4KHZ. The contact should be audible in eastern Australia. Interested parties are invited to listen in on the 145.80 MHz downlink. In addition, the audio should be available via IRLP and EchoLink. The participants are expected to conduct the conversation in English.

McCall-Donnelly School District consists of two high schools, one middle school, and two elementary schools for approximately 900 students. The school district's motto is "Educating Students for Life". Located in McCall, Idaho; the district is nestled in amongst the Payette National Forest. A former logging community, McCall located about 100 miles north of Boise and is now considered a year round resort destination with the nickname "Ski Town USA". Barbara Morgan taught in the district for years and was an active member of the community. The district science team works closely with the State Department of Education and the University of Idaho as members of Idaho Reaches Into Space (IRIS) to coordinate classroom activities and assemblies developed by NASA aerospace educators and aligned to Idaho achievement standards.

The International Space Station has a new control moment gyroscope, which is in the process of being checked out by Mission Control.

Mission Specialists Dave Williams and Rick Mastracchio completed a spacewalk that has been in the works since one of the station's four gyroscopes - which control orientation - failed in October. Williams carried the 600-pound replacement to its new home on the Z1 segment of the station truss, and stored the failed equipment on the outside of the station. It will be returned home on a future shuttle mission.

The second of four spacewalks scheduled for Endeavour's mission, this was the 90th spacewalk devoted to station maintenance and construction. Williams and Mastracchio left the station at 10:32 a.m. and spent 6 hours and 28 minutes outside.

The Expedition 15 crew and the visiting STS-118 crew continue joint operations aboard the International Space Station.

Since the seven STS-118 astronauts arrived on Aug. 10, the station has grown in size and received a new attitude control gyroscope during two spacewalks. The Starboard 5 (S5) truss segment was attached Saturday during STS-118's first spacewalk. The S5 will serve as a spacer segment between the Starboard 4 and 6 (S6) segments. The S6 and its solar arrays will be attached during a future shuttle mission.

http://www.amsat.org/amsat/archive/sarex/48hour/msg00944.html