What caused the challenger to blow up?

Answer 1

The ground level temperature was 36 F. 15 F colder than any other launches. After 0.68 seconds, black smoke was coming from the AFT joint of the right rocket booster. Then seventy-two seconds after launch a chain of events caused the shuttle to explode. First, the lower strut connecting the right rocket booster to the external tank was extremely hot and weak. Second, the force that was on the strut made it break away from the right rocket booster and the external tank. Third, since the strut broke away from the right rocket booster, this allowed the right rocket booster to spin freely. With the right booster spinning freely, the bottom was burning, hitting, and denting the challengers' wing. The inside of the external tank had ruptured and was letting out liquid hydrogen. The top of the rocket was hitting the top of the external tank and also broke the oxygen tank. The vapor that these two chemicals made it very dangerous. The vapor is what made the main explosion. This explosion is what killed all six astronauts plus the one civilian.