The space shuttle Challenger was one of NASA’s greatest accomplishments. On April 4, 1983, it became the second shuttle to reach space. Space shuttle Challenger had successfully completed nine milestone missions. But Challenger was also NASA’s darkest tragedy. On Jan. 28, 1986, in its 10th launch, the shuttle exploded 73 seconds after lift-off. The accident changed the space program forever.
The mission was scheduled to be launched on January 22,1986 carrying a seven-member crew that included Christa McAuliffe, a social studies teacher who was set to become the first ordinary American citizen to travel into space. The mission’s scheduled launch from Kennedy Space Center at Cape Canaveral, Florida, was delayed for six days due to weather and technical problems.
It was a strangely cold morning on Jan. 28, 1986. Temperatures dipped below freezing. Some people at NASA and among contractors were worried about the integrity of the seals on the solid rocket boosters in such a cold weather. Engineers warned their superiors that certain components—particularly the rubber O-rings that sealed the joints of the shuttle’s solid rocket boosters—were prone to failure at low temperatures. However, these warnings went unheeded, and at 11:38 a.m. Challenger lifted off.
Seventy-three seconds later, hundreds on the ground, together with the families of the astronauts on board, stared in disbelief as the shuttle broke up in a cloud of smoke and fire. Millions more watched the tragedy unfold on live television. Recovery crews spent several weeks recovering pieces of the shuttle and carefully, bringing up the remnants of the seven astronauts. Remnants that could be recognized were turned over to the families, while the rest were buried in a monument to the Challenger crew at Arlington Cemetery on May 20, 1986.
Shortly after the disaster, President Ronald Reagan appointed a special commission, ‘Rogers Commission’ to determine what went wrong with Challenger and to develop future corrective measures. Rogers Commission’s investigation discovered that the O-ring seal on Challenger’s solid rocket booster failed as it had become brittle in the cold temperatures. The commission also found that Morton Thiokol, the company that designed the solid rocket boosters, had ignored warnings about potential issues. NASA managers were aware of these design problems but also failed to act. The engineers at Morton Thiokol were concerned about the cold temperature on launch day and the consequence the cold would have on the solid rocket booster O-rings. The O-rings were designed to operate at an ambient temperature of not less than 40 degrees Fahrenheit. On the day of the launch, the ambient temperature was 30 degrees. Concerned about the brittleness of the O-rings, Thiokol told NASA that the launch needed to be postponed. NASA objected to the recommendation to delay the launch. Thiokol management, facing pressure from NASA, eventually complied and agreed that the launch could proceed. Rather than redesigning the joint, they came to define the problem as an acceptable flight risk. The failure of the O-rings was attributed to a faulty design, whose performance could be too easily compromised by factors including the low temperature on the day of launch.
Investigations later determined that the primary cause of the accident was a leak within the SRB joint, which had allowed superheated gas to escape and burn through the booster and the external tank, causing structural collapse. The post-flight analysis indicated that the cold temperature was a contributing factor. So was the SRB joint’s design and NASA’s decision-making process. It was like a perfect storm of combined circumstances.
When Morton Thiokol engineer Robert Ebeling was interviewed, he told the story of how he and four other engineers did not want the Challenger to be launched due to cold weather conditions. Despite their concern, NASA launched the shuttle anyway. They failed to convince NASA to postpone the launch due the work pressure on them by the management and the NASA. For the remainder of his life, Ebeling blamed himself for not saying a ‘NO’ to convince NASA to delay the Challenger launch.
Many times, a decision will come down to judging the risks of innumerable courses of action. When the possible result of a course of action is catastrophic even if the probability of it occurring is low, one should not take the risk. Unfortunately, the NASA decision makers who moved ahead with the Challenger launch did not think in these terms.
The Challenger accident has frequently been used as a case study in the study of subjects such as safety engineering , group decision-making, effective communication within the group and the dangers of group thinking. This disaster teaches that a slight compromise on safety can lead to a catastropic disasters.
https://en.wikipedia.org/wiki/Space_Shuttle_Challenger_disaster https://www.history.com/topics/1980s/challenger-disaster https://www.space.com/31760-space-shuttle-challenger-disaster-30-years.html