But in the bottom-most field joint of the right-hand booster rocket, the cold had done its work: the synthetic rubber of the seals and the thick grease they were packed in had proved too inflexible to close the gap that opened in the case at ignition. Hot gas at more than 5,000 degrees Fahrenheit had blasted past the primary seal—and then broken through the second seal, too, instantly vaporizing portions of the O-rings as it went. Unseen by the crowd or the officials in the Launch Control Center, burning grease, insulation, and Viton rubber spurted from the ruptured joint in puffs of
...more
