Space Shuttle Explosion is the 44th episode of Seconds from Disaster explaining how did Challenger was destroyed just 73 seconds after launch.
Space Shuttle Challenger takes-off from Cape Canaveral to start the STS-51-L mission. In 1986, Challenger was the most reliable shuttle. However, it only flew 9 successful missions. Before the disaster, Roger Boisjoly asked for the Challenger mission to be delayed because it was too cold for the launch. He said that the year before Challenger's fateful flight, Space Shuttle Discovery almost shared the same fate. The SRBs showed O-ring corrosion. Discovery was launched during the coldest weather, and was surpassed by the fateful mission of Challenger. Challenger was launched close to 10 degrees Centigrade. However, NASA decided to launch Challenger despite the cold weather. Then, 73 seconds in flight, Challenger exploded, killing all 7 astronauts. The crew cabin was still intact after a few seconds into the disaster. Then, NASA could not find the crew cabin, and reported that all the crew died.
The cold temperature did not allow the O-rings to seal completely, allowing hot fuel to leak out. This was the smoke from the right solid rocket booster. A piece of metal sealed the leak, but a jet strem pushed it away. Around one minute in the flight, fire was coming out of the booster. This flame burned the hydrogen and fuel in the external fuel tank. The chemicals rapidly combusted, blowing the shuttle in pieces. The crew cabin crashed in the sea, killing all 7 astronauts.