Challenger disaster

The Space Shuttle Challenger disaster occurred on January 28, 1986, when Space Shuttle Challenger broke apart 73 seconds into its flight, leading to the deaths of its seven crew members. The spacecraft disintegrated over the Atlantic Ocean, off the coast of central Florida, United States at 11:39 a.m. EST (16:39 UTC).

Disintegration of the entire vehicle began after an O-ring seal in its right solid rocket booster (SRB) failed at liftoff. The O-ring failure caused a breach in the SRB joint it sealed, allowing pressurized hot gas from within the solid rocket motor to reach the outside and impinge upon the adjacent SRB attachment hardware and external fuel tank. This led to the separation of the right-hand SRB's aft attachment and the structural failure of the external tank. Aerodynamic forces promptly broke up the orbiter.

The crew compartment and many other vehicle fragments were eventually recovered from the ocean floor after a lengthy search and recovery operation. Although 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. However the shuttle had no escape system and the astronauts did not survive the impact of the crew compartment with the ocean surface.

The disaster resulted in a 32-month hiatus in the shuttle program and the formation of the Rogers Commission, a special commission appointed by United States President Ronald Reagan to investigate the accident. The Rogers Commission found that NASA's organizational culture and decision-making processes had been a key contributing factor to the accident. NASA managers had known that contractor Morton Thiokol's design of the SRBs contained a potentially catastrophic flaw in the O-rings since 1977, but they failed to address it properly. They also disregarded warnings from engineers about the dangers of launching on such a cold day and had failed to adequately report these technical concerns to their superiors. The Rogers Commission offered NASA nine recommendations that were to be implemented before shuttle flights resumed.

Many viewed the launch live due to the presence on the crew of Christa McAuliffe, the first member of the Teacher in Space Project. Media coverage of the accident was extensive: one study reported that 85 percent of Americans surveyed had heard the news within an hour of the accident. The Challenger disaster has been used as a case study in many discussions of engineering safety and workplace ethics and inspired the 1990 television movie, Challenger.

Media coverage
While the presence of schoolteacher Christa McAuliffe on the Challenger crew had provoked some media interest, there was little live broadcast coverage of the launch. The only public live national coverage was provided by CNN. Due to McAuliffe's presence on the mission, NASA arranged for many U.S. public schools to view the launch live on NASA TV. As a result, many who were schoolchildren in the US in 1986 did in fact have the opportunity to view the launch live. After the accident, however, 17% of respondents in one study reported that they had seen the shuttle launch, while 85% said that they had learned of the accident within an hour. As the authors of the paper reported, "only two studies have revealed more rapid dissemination &#91;of news&#93;." (One of those studies was of the spread of news in Dallas after President Kennedy's assassination, while the other was the spread of news among students at Kent State regarding President Franklin D. Roosevelt's death.) Another study noted that "even those who were not watching television at the time of the disaster were almost certain to see the graphic pictures of the accident replayed as the television networks reported the story almost continuously for the rest of the day." Children were even more likely than adults to have seen the accident live, since many children—forty-eight percent of nine to thirteen-year-olds, according to a New York Times poll—watched the launch at school.

Use as case study
The Challenger accident has frequently been used as a case study in the study of subjects such as engineering safety, the ethics of whistle-blowing, communications, group decision-making, and the dangers of groupthink. It is part of the required readings for engineers seeking a professional license in Canada and other countries. Roger Boisjoly, the engineer who had warned about the effect of cold weather on the O-rings, left his job at Morton Thiokol and became a speaker on workplace ethics. He argues that the caucus called by Morton Thiokol managers, which resulted in a recommendation to launch, "constituted the unethical decision-making forum resulting from intense customer intimidation." For his honesty and integrity leading up to and directly following the shuttle disaster, Roger Boisjoly was awarded the Prize for Scientific Freedom and Responsibility from the American Association for the Advancement of Science." Many colleges and universities have also used the accident in classes on the ethics of engineering.

Information designer Edward Tufte has used the Challenger accident as an example of the problems that can occur from the lack of clarity in the presentation of information. He argues that if Morton Thiokol engineers had more clearly presented the data that they had on the relationship between cold temperatures and burn-through in the solid rocket booster joints, they might have succeeded in persuading NASA managers to cancel the launch. Tufte has also argued that poor presentation of information may have affected NASA decisions during the last flight of Columbia.