Another team of technicians is working on repairing cracks on the tops of two, 21-foot-long support beams, called stringers, on the exterior of the external tank in an area known as the intertank. The team includes personnel from the external tank manufacturing plant in Louisiana, the Michoud Assembly Facility.
Over the weekend, technicians removed a section of one of the stringers that had two, 9-inch cracks in it. Last Friday, during foam removal and inspection of adjacent stringers to the one with the 9-inch cracks, technicians identified a crack about 3-inches long on the left-hand adjacent stringer. Further foam removal revealed one additional corresponding crack on the same left-hand adjacent stringer. Technicians plan to remove that section of the stringer Monday night. They’ll also install a new section of metal, called a doubler because it’s twice as thick as the original stringer metal, on the stringer that had the 9-inch cracks.
Engineers continue evaluating the intertank for any potential issues, but so far no other cracks have been found beyond the ones on the two previously identified stringers. There are a total of 108 stringers on the intertank.
Senior managers plan to meet on Nov. 22 at NASA’s Johnson Space Center and via video conference for a launch status briefing to assess and review the repair work and launch preparations. Although managers have not set a new target launch date for Discovery’s STS-133 mission to the International Space Station, the repair work and planning still are aimed at supporting an attempt in the upcoming launch window that opens Nov. 30.