Jan. 28, 1986: The Space Shuttle Challenger, STS-51L, was tragically destroyed and its crew of seven was killed, during its launch from the Kennedy Space Center about 11:40 a.m. The explosion occurred 73 seconds into the flight as a result of a leak in one of two Solid Rocket Boosters that ignited the main liquid fuel tank. The crewmembers of the Challenger represented a cross-section of the American population in terms of race, gender, geography, background, and religion.

The explosion became one of the most significant events of the 1980s, as billions around the world saw the accident on television and empathized with any one of the several crewmembers killed. The disaster prompted a thorough review of the shuttle program and NASA overall, leading to substantive reforms in the management structure, safety program, and procedures of human spaceflight.  73 seconds into the flight, photographic data show a strong puff of gray smoke was spurting from the vicinity of the aft field joint on the right Solid Rocket Booster.

The two pad 39B cameras that would have recorded the precise location of the puff were inoperative. Computer graphic analysis of film from other cameras indicated the initial smoke came from the 270 to 310-degree sector of the circumference of the aft field joint of the right Solid Rocket Booster. This area of the solid booster faces the External Tank. The vaporized material streaming from the joint indicated there was not complete sealing action within the joint. Eight more distinctive puffs of increasingly blacker smoke were recorded between .836 and 2.500 seconds.

The smoke appeared to puff upwards from the joint. While each smoke puff was being left behind by the upward flight of the Shuttle, the next fresh puff could be seen near the level of the joint. The multiple smoke puffs in this sequence occurred at about four times per second, approximating the frequency of the structural load dynamics and resultant joint flexing. Computer graphics applied to NASA photos from a variety of cameras in this sequence again placed the smoke puffs' origin in the 270-to 310-degree sector of the original smoke spurt. (Click here to continue with this story). You can also read the transcript of the Space Shuttle explosion.  See A Short Movie On The Explosion