3rd spacewalk still an option for Discovery's crew

Today's marathon shuttle press briefings at Johnson Space Center have yielded no real surprises, but one interesting tidbit of note: Wayne Hale is optimistic about the chances of a third spacewalk on Discovery's mission this summer.

Flight planners had dropped the spacewalk from the schedule earlier this year, partly because of a tight schedule. The plan all along has been to add the spacewalk back in if shuttle life support resources are available to extend the mission.

That would be preferred, Hale said today, because the spacewalk involves further testing of heat-shield repair tools and techniques. NASA has struggled to find the kinds of repair methods that it would deem as "certified" for re-entry, the agency has continued to develop a range of techniques that could be used as a last resort.

Hale wants to get the testing done on a third spacewalk on this flight because, after this one, the schedules for subsequent missions are cram-packed with critical assembly tasks necessary to finish building the International Space Station.

Upon questioning from reporters this morning, Hale would not commit to adding the testing on a subsequent shuttle flight. He did not rule it out either. Rather, he pointed out the busy nature of the flight plans for the remaining construction missions would make it difficult to fit in more heat-shield repair tests.