Public domain image provided by NASA

Challenger disaster

On 28th January 1986, during flight STS-51-L, the space shuttle Challenger and the seven crew members on board were lost when a ruptured O-ring in one of the solid rocket boosters caused an explosion soon after launch.

The photo above was taken mere seconds after the accident. It shows the exhaust plumes from the main engines and boosters intertwined with a ball of gas from the external fuel tank.

The O-ring was not designed to fly under the unusually cold conditions of this particular launch, and its rupture allowed pressurized burning gas from the rocket motor to reach the outside and weaken the joint where the opposite rocket booster was attached. This led eventually to the structural failure of the external tank, and aerodynamic forces broke up the craft.

Public domain image provided by NASA

Many fragments of the shuttle were recovered after a lengthy recovery operation, including the crew compartment. Several crew members are known to have survived the initial explosion and breakup of the vehicle, but the shuttle had no escape system and the impact of the compartment with the ocean surface would have been too violent to have been survivable.