Surprisingly, many people don't know what exactly happened to the Challenger. Ironically there were several launch delays for the Challenger. NASA disregarded the delays and ordered the lift off anyway.(Oberg, 725) Seventy-eight seconds into the flight the Challenger tragically exploded. The accident occurred at 46,000 feet in the air. The Challenger was traveling at about twice the speed of sound. Technically, the Challenger did not exploded, it fell apart due to structural failures. The crew cabin broke lose from the entire shuttle and went flying through the air. The crew cabin hit the Atlantic ocean within three minutes. The seven-crew members that belonged to the space shuttle were killed on impact. (725)

Because of the seriousness of what happened in the Challenger accident a special team wa

5. The solid rocket motor joint has design deficiencies and my not seal properly with combined variable conditions existing on 51-1. Tests conducted during this investigation indicated that:

Ice in the joint was cited as another factor inhibiting seal performance. (Grunwald, 88)

4. The location of the right solid rocket motor aft field joint combustion gas leak coincided with the approximate location of maximum interference between the joint tang and inner clevis leg at assembly. This mating interference can exist using approved assembly procedures.

ing surface, the team reported. Test indicate that sealing capability is marginal for maximum squeeze conditions-0.004 inches initial gap at 50 degrees -with a pressure delay of 500 milliseconds. The report then applied this reasoning to Challenger's right solid motor: "For the temperature and O-ring squeeze conditions which existed for several of the 51-L filed joints, sealing was not achieved in these test with simulated putty rapture times of 250 and 500 milliseconds."(58)

Putty performance in the joint may not be as intended by the design. (McGowen, 58) Tests indicate that humidity can delay timely actuation pressure to the O-rings. Testing and the de-stacking of the boosters for 61-G (intended for Atlantis) showed that several blowhole gas paths per joint can existed at motor ignition and can concentrate hot gas flow, causing O-rings to erode. (58)

3. The joint was observed leaking combustion gas within the first seconds after ignition. The leak became clearly evident at approximately 58 seconds into the flight. It is possible that the leak was continuous but unobservable or nonexistent in portions of the intervening period.

6. The joint that failed was not found to be unique. It was therefore necessary to modify the solid rocket motor joint design to preclude or eliminate the effects of all these factors and conditions acting singly or in combinations." (88)

rings. Mating conditions there afforded the highest potential for undetected joint damage performance.

Another major contributor to the explosion was a leaking joint. The Data and "Design Analysis Task Force then came to these conclusions, which served as the basis for the Presidential Commiss

Some common words found in the essay are:
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Approximate Word count = 1513
Approximate Pages = 6 (250 words per page double spaced)