<Li> Christa McAuliffe, Payload Specialist, Teacher </Li> <Tr> <Th> Inquiries </Th> <Td> Rogers Commission </Td> </Tr> <P> On January 28, 1986, the NASA shuttle orbiter mission STS - 51 - L and the tenth flight of Space Shuttle Challenger (OV - 99) broke apart 73 seconds into its flight, killing all seven crew members, which consisted of five NASA astronauts and two payload specialists . The spacecraft disintegrated over the Atlantic Ocean, off the coast of Cape Canaveral, Florida, at 11: 39 EST (16: 39 UTC). The disintegration of the vehicle began after a joint in its right solid rocket booster (SRB) failed at liftoff . The failure was caused by the fact that O - ring seals used in the joint were not designed to handle the unusually cold conditions that existed at this launch . The seals' failure caused a breach in the SRB joint, allowing pressurized burning gas from within the solid rocket motor to reach the outside and impinge upon the adjacent SRB aft field joint attachment hardware and external fuel tank . This led to the separation of the right - hand SRB's aft field joint attachment and the structural failure of the external tank . Aerodynamic forces broke up the orbiter . </P> <P> The crew compartment and many other vehicle fragments were eventually recovered from the ocean floor after a lengthy search and recovery operation . The exact timing of the death of the crew is unknown; several crew members are known to have survived the initial breakup of the spacecraft . The shuttle had no escape system, and the impact of the crew compartment with the ocean surface was too violent to be survivable . </P>

What was the cause of the space shuttle challenger disaster
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