The crack was traced to a manufacturing defect: a titanium weld that had cooled too quickly in 1989, creating a microscopic martensitic phase inclusion. That tiny inclusion cycled through 18 flights (STS-118 was Endeavour’s 20th mission) before finally propagating. The 2007 crack is a haunting case study in risk management. Unlike the dramatic foam strike of Columbia , this was a quiet, cumulative failure—a slow betrayal by metallurgy. It revealed that even after the most rigorous post-Columbia redesigns, the Shuttle remained a fragile, aging machine held together by inspection intervals and statistical margins.
STS-118 was no exception. Launched on August 8, 2007, Endeavour carried the SPACEHAB module and the S5 truss to the International Space Station (ISS). Commander Scott Kelly led a crew of seven. At T+58 seconds into ascent, a 0.25-pound piece of foam insulation—precisely the kind that doomed Columbia —broke away from the external tank’s (ET) "bipod ramp" region and struck the underside of Endeavour near the landing gear door. High-resolution post-launch imagery revealed a gouge in tile number V6 (a reinforced carbon-carbon tile near the nose landing gear door). The gouge measured approximately 3.5 inches by 2 inches, with a depth of nearly 1 inch. Space Shuttle Mission 2007 Crack
In the end, the 2007 crack stayed small enough to ignore but large enough to remember. It was the sound of a program’s structural integrity quietly sighing under the weight of its own history. If by "Space Shuttle Mission 2007 Crack" you were referring to a different event—such as a crack in a window, a fuel line, or a simulation exercise—please provide more context, and I will refine the response accordingly. The crack was traced to a manufacturing defect: