The SRBs and the Shuttle's Failure

The space shuttle Challenger exploded 73 seconds after liftoff on March 28, 1986. The launch pad was covered in ice and temperatures were too low for the rubber O-rings used to seal the joints on the solid rocket boosters. If the primary O-rings fail, there are secondary ones that kick in; if those fail, the shuttle could destruct. A team works to remove the ice, but the temperatures are dangerously low.