The reason Challenger's solid rocket booster didn't immediately begin extruding the flame which, at 73 seconds caused it to burn through its attachment and strike the fuel tank, was because aluminium oxide (a relatively recently added fuel-efficiency measure) present in the SRB created a 'slag' which fortuitously plugged the hole in the now burned-through O-Ring. It was only because Challenger, at 58 seconds, was struck by the strongest wind gust in the history of any launch that the 'plug' was dislodged - causing the now infamous blowtorch-like flame to appear from the SRB which preceded the shuttle's destruction. Challenger required little over a minute after the moment of its break-up to reach the point where the SRB's fuel would have been exhausted and they could have been safely detached from the shuttle - thus allowing the Challenger, and its crew, to safely reach space.