Uncontrolled ballistic trajectory
The CAIB report concluded that during re-entry, a breach in the Shuttle’s thermal protection system “allowed superheated air,” at temperatures reaching 2,760 degrees Celsius, to “penetrate through the leading edge insulation and progressively melt the aluminum structure of the left wing, resulting in a weakening of the structure until increasing aerodynamic forces caused loss of control, failure of the wing, and breakup of the orbiter.”
The Spacecraft Crew Survival Integration Investigation Team (SCSIIT) concluded that the loss of hydraulics caused Columbia to pitch upwards, as the Shuttle transitioned from “a controlled gliding trajectory into an uncontrolled ballistic trajectory,” the SCSIIT team wrote in its report.
