Morton-Thiokol

MORTON-THIOKOL is best known for its role in the explosion of the space shuttle Challenger on January 28, 1986. In 1973, Thiokol Chemical Corporation (later the company became Morton Thiokol, Inc.) was awarded an $800 million contract to manufacture solid rocket boosters for the National Aeronautics and Space Administration (NASA) [Page 548]space shuttle program. The faulty O-ring seals developed by Thiokol ultimately failed in the right side solid rocket booster and caused the explosion of the spacecraft.

Morton-Thiokol tests a redesign of the solid rocket booster after the explosion of the space shuttle Challenger.

A subsequent investigation by the President's Commission on the Space Shuttle Challenger Accident, 1986, (the Rogers Commission), concluded that the failure of the O-rings and field joint was the primary cause of the Challenger explosion.

Early tests conducted by Thiokol indicated severe problems with the field joints on solid rocket boosters. Instead of closing and preventing the seepage of gases, the field joints were open and allowed hot combustion gases to leak and erode the O-rings. The erosion of the O-rings would necessarily cause the joints to explode, destroying the entire booster in the process as well as the spacecraft.

The failure of the field joints even destroyed secondary or failsafe O-rings. NASA's Marshall Space Flight Center classified the O-ring seals as Criticality 1, meaning they did not meet space shuttle requirements for failsafe standards. As such, the O-rings were considered extremely hazardous because they were subject to metal erosion, burning, and explosion.

Several Thiokol engineers openly expressed their concerns about the potential catastrophic costs associated with the faulty O-rings. One engineer, Roger Boisjoly, wrote a memo expressing these concerns about the O-rings and strongly urged the company to develop a team dedicated to quickly solving the problems. A task force was formed to investigate problems with the O-rings and field joints. However, they never reached a conclusion or solution to the problem primarily because of a lack of resources and reluctance by management to fully investigate the problem.

At the time, the company was in the process of renegotiating its contract with NASA. Seriously researching and resolving the O-ring problem most likely would have resulted in a lengthy delay of the shuttle launch, jeopardized the potentially lucrative second contract with NASA, and ultimately adversely affected Thiokol's profits. Eventually, Thiokol requested that NASA consider the O-ring problem resolved and just five days before the Challenger launch, officials at Marshall considered the matter closed.

Beyond erosion problems, Thiokol engineers also had knowledge that cold weather conditions severely affected the ability of the O-rings to effectively compress and contract and therefore seal out hot gases. The day before the Challenger launch, Thiokol engineers were concerned about the unexpectedly low temperatures at the Kennedy Space Center in Florida and contacted NASA officials to discuss the potential hazards of launching under cold weather conditions. Thiokol engineers recommended that the launch be delayed and not take place until weather conditions were about 53 degrees Fahrenheit.

This recommendation was not well received by NASA officials who were adamantly opposed to any further delays and Thiokol's conclusions regarding temperature levels. In this respect, Thiokol was under tremendous pressure to change their launch recommendation. Despite strong objections from Thiokol engineers, officials at the company reversed their position and approved the launching of the Challenger.

...