#Fractured space endeavor crew crack
“All of the cracks found during tanking as well as cracks fixed during manufacturing were located on stringers made with this mottled material.”įurthermore, engineers were finally able to recreate the stringer crack failure seen on Discovery’s ET using the stringers from the partially-built ET-139 at the Michoud Assembly Facility (MAF).īy January 6, the all-powerful Program Requirements Control Board (PRCB) had directed teams to proceed forward with the radius block modification on well over 100 of Discovery’s tank stringers – a decision that further emphasized the drive for safety and understanding over launch date pressure. Testing revealed this mottled material had lower fracture toughness than the nominal material and exhibited unstable crack growth. On January 4, NASA identified the potential root cause for the stringer issue – a mottling on the stringers themselves.Īs noted by an investigation report, “Some material used for the stringers was found to be ‘mottled,’ with a different surface appearance than the standard material. STS-133 Specific – Including ET Stringer Issue – Articles: ( L2 Link).ĭiscovery, the third operational Shuttle orbiter and fourth overall Shuttle orbiter constructed by NASA, was preparing for her 39th and final mission in November 2010 when the stringer crack issue presented itself during the mission’s first launch attempt on November 5, 2010.įollowing the discovery of this issue, NASA mission managers refused to set a launch date for the flight in a concerted effort to allow the engineering analysis teams to have the time they needed to properly and safely address the issue without feeling a push toward launch fever. OV-103/Discovery – The final voyage of the veteran workhorse:įor the final year of the Space Shuttle Program, operations in 2011 began where all Shuttle missions have: in the Vehicle Assembly Building.Īfter enduring a rollback from LC-39A in late-December 2010, because of cracks on the stringers of her External Tank’s (ET) intertank structure, Space Shuttle orbiter Discovery, OV-103, spent the first month of 2011 in the VAB undergoing ET intertank repairs and strengthening activities while the various NASA centers conducted numerous simulations to nail down the cause of the ET stringer cracks.
It was year of exceptional highs and emotional scenes as Discovery, Endeavour, and Atlantis closed out their remarkable careers with same style, grace, mission success, and safety that all had come to know from them. And thus was the grand finale of the Space Shuttle Program in 2011.