Fourth spacewalk, repair decision face delays

NASA mission managers will meet at the top of the hour to discuss the possibility of sending spacewalkers later this week on an excursion to repair gouged tiles on the underside of Endeavour.

The managers are leaning toward delaying an already planned spacewalk from Friday to Saturday. That would give them another day to examine the results of additional testing before making a final decision Thursday on tile repair work.

The move also would enable Endeavour's astronauts to complete the fourth spacewalk of the mission and still depart the International Space Station as scheduled next Monday in the event that no repair work is required.

Up for review at the meeting: the latest data from tests in which thermal tile samples with damage near identical to the Endeavour gouge were put through a reentry simulator. The tile samples were exposed to the same temperatures and aerodynamic environment Endeavour's underside will encounter during atmospheric reentry.

The idea is to determine whether the gouge would allow hot gasses to damage the orbiter's aluminum airframe, and if so, the extent of any damage that might be done. The results will help managers determine whether spacewalking repair work is necessary.

NASA briefed the astronauts on the latest earlier today. You can take a look at the Mission Management Team (MMT) summary beamed up to the astronauts in their Flight Day 8 Execute Package here: FD08_Execute_Package.pdf.

NASA will brief reporters at a news conference now scheduled for 7 p.m. EDT. You can watch a live webcast of the briefing here in The Flame Trench. Simply click the link below the image above, or the link below the Mission Webcast headline, to launch our NASA TV viewer. Start up time is about 20 seconds.

The latest NASA TV schedule for the mission -- Rev L -- is here: tvsked_revl.pdf