NASA has made changes in the external fuel tank foam insulation since a piece of foam damaged the shuttle Columbia and caused it to come apart during re-entry back in 2003. More changes were made after Discovery's first post-Columbia flight a year ago, and despite some ongoing internal disagreements, NASA spokesman Kyle Herring says shuttle program managers and NASA Administrator Michael Griffin are satisfied it's ready to fly again.
"The Administrator himself made it very clear that from a safety of flight standpoint, any foam that would come off the tank, which, albeit very small, based on the work that we've done over the course of the last year, would not damage the orbiter, and if it did it would not be a safety of flight issue in terms of the ascent or the crew."
Herring says assuming launch goes as planned Saturday afternoon, Discovery will take supplies and a new crewman to the International Space Station.
"This will be a return to a three person station crew that we have not had since shortly after the Columbia accident, obviously. We'll be delivering European Space Agency astronaut from Germany Thomas Reiter to the station. So the shuttle will launch with seven and come home with six."
During the two week mission, Discovery astronauts will go EVA to repair the station's external robotic arm assembly and practice repairing the shuttle's heat shield in zero-G, using new tools specially designed for that work. Jim Bell, Houston Public Radio News.