Success Breeds Confidence and Fantasy the Challenger Disaster

Could the challenger disaster have been avoided? I once heard a smart man say “Never get to confortable with what you are doing and if you get to confortable change your work”. The challenger disaster was the product of over confidentiality of the engineers working in the project. The problem that the challenger had been a failure of the O-rings in the engine, these O-rings failed to keep gases inside the engine. When the challenger was launched the O-ring failed to keep all the gases inside the engine, the gases started to scape, when the leakage permitted enough gases to escape the fire that the rocket booster has normal from ignition was what made the explosion. The fire of the rocket booster finds its way inside to the engine and made the fuel ignite. They did not have the chance to even know that something was wrong, the rocket exploded.

The temperature was not taken into consideration, engineers reported that morning that the temperature of that day was not favorable for the launch; this important detail never got to the knowledge of top management and was ignored completely. The confidence that the engineers wrongfully gained was because of previous 24 successful launches, the thought that the probabilities for a disaster was almost impossible, they should of kept in mind that the probabilities where 1 over 25 not 24 over 25.When people think they have a problem solved, they often let up; which means they stop making continuous adjustments. Also, managers lost fear of design a problem. If the appropriate safety guidelines were followed this will probably would never had occur and the life of seven astronauts would not been taken in vain. This is a clear error that could have been prevented if the engineers working in that project have not get to comfortable working in high risk technologies on a day to day basis. In such organizations, these normal patterns of behavior create the potential for tragedy.

1. Introduction
There are events that are experienced by numerous amounts of people, regardless of their age, gender, culture, language, who come together by a symbolic moment in history. The accident of the Challenger Space Shuttle was a moment like the one previously explained. On January 28, 1986, the space shuttle Challenger was supposed to go into space but instead it just exploded into a ball of fire shortly after liftoff. Every astronaut inside the shuttle was died. This event has led into better engineering ethics, not just inside NASA but throughout the discipline. After this incident NASA was forced to put their feet down to earth, and started to take different approaches into their ethics. One of the most important things that an engineer must have is good ethics, in a project like this quantity cannot go over quality, not when there are lives in the line. The technical reason why the shuttle burst into flames was because of the solid rocket booster O-rings to seat properly allowed hot combustion gases to leak from the side of the booster and burn trough the external fuel tank. The failure of this ring was a result of several factors which include: faulty design of the solid rocket boosters, insufficient low temperature testing of the O-ring material and the joints at the O ring sealed, and also a problem in communicating within different levels of NASA personnel managers.

2. Background
The Challenger Space shuttle was one of only five NASA orbit shuttles to have gone in space and is the only case that has been registered as a loss in an accident to date. The shuttle had previous launches between 1983 and 1985, unfortunately on its tenth flight the shuttles lifetime would come to an end, along with its passengers. The development of the shuttle started off in the middle of the 1970s as design to show engineers how a shuttle can handle the stresses of flying in space. Eventually the rocket design became a space orbiter potential in 1982 after a handful of successful flights which gave false hope to NASA of being a step ahead of the game. By 1985 there were nine successful flights and the tenth flight was planned on 1986 to send the first teacher in space, fix a communications satellite, and study the comet Halley. At the time of launch, two solid rocket boosters attached to an external tank exploded and caused the tragic accident. 2.1 Solid Rockets (SRB)

One the many ideas of why “The Challenger” fail is because the Solid Rocket (SRB) did not work as expected. Based on the numbers provided by previous flights, the SRB had to work perfectly. However the Challenger was the first time flying which make the range of failure bigger, but it was not high enough to take into consideration. “Out of a total of nearly 2,900 flights, 121 failed (1 in 25). This includes, however, what may be called, early errors, rockets flown for the first few times in which design errors are discovered and fixed. A more reasonable figure for the mature rockets might be 1 in 50.” With the data provided, there was a small probability of a catastrophe to occur, even when it was the first time flying. NASA strongly disagrees with the data provided. They argue that the numbers provided are for unmanned rockets and the Challenger was manned rocket. NASA argues that the probability of failing would be 1 in 100,000 in a manned flight. “It is true that if the probability of failure was as low as 1 in 100,000 it would take an inordinate number of tests to determine it.”

The probability of failure in a Solid Rocket provided by NASA is extremely odd. The numbers provided by NASA are in some way unreal. It would have to take thousands of trials in order to get a problem. With this numbers the probability of failing is irrelevant in the rocket. However we all know that every project as to be tested many times in order to get a failure and fix the problem in order to achieve close to a perfect flight. The trials are very important for a solid rocket. Every probability of failing in a Solid Rocket is double because the rocket uses two of them. Previous flights ended up without any accident; however the fact that it was able to finish the flight without any failure does not mean the flight was perfect. Previous flights were accepted, but there was a signal of something was wrong in the rocket. The Challenger is another example of these flights. There was an erosion and blow-by in the seals of the flights. Accepting the flights with these signals that there is something wrong with the rocket is a bad choice.

“The acceptance and success of these flights is taken as evidence of safety. But erosion and blow-by are not what the design expected. They are warnings that something is wrong. The equipment is not operating as expected, and therefore there is a danger that it can operate with even wider deviations in this unexpected and not thoroughly understood way.” The fact that the NASA accepted the flights with this signals that the rocket was not working perfectly is something unreasonable. The fact the previous flights did not ended in a catastrophe, does not assure the next flight would end up the same successful way. The whole group involved in the Challenger project took a risky decision; which ended in a catastrophic failure. Not taking to consideration what previous flights showed, and fixed it was a complete failure. The challenger did not fail during the actual flight, but it failed since the preparation. The members of the group knew something could have gone wrong, but none of them did anything to prevent the accident. This accident could have been prevented in previous flights.

2.2 Liquid Fluid Engine
Another important part of the rocket that was taken into consideration was the Liquid Fuel Engine (SSME). Members of the group stated that the Space Shuttle Main Engines were working perfectly; they started to fail at the beginning of the shutdown. The engine is a part of the rocket that is way more complicated than the Rocket Booster. In order to investigate the engines the member of the crew must be necessary to understand fully the properties and limitations. “The engine was designed and put together all at once with relatively little detailed preliminary study of the material and components. Then when troubles are found in the bearings, turbine blades, coolant pipes, etc., it is more expensive and difficult to discover the causes and make changes.”

The engines like those stated in the quote are very difficult to examine. The parts that were placed together to form the entire engine are very complex. This way of building the engine is called “top-down method”. In order to find want did not work as planned the member must know exactly was the materials used in every part and how it works. It would be a waste of thousands of dollars to revise and repair. However it is necessary for the group to examine what went wrong in order to prevent a future accident. “Without detailed understanding, confidence cannot be attained.” Another disadvantage of the top-down method is that a simple fixed such as remodeling would take a whole new engine, built from scratch. Studies showed that the engines failed about sixteen times in the first 250,000 seconds. Engineers study the failing parts closely in order to fix them as soon as possible. After all the investigations most of the problems in the engines got fixed.

The principles of these engines were very difficult to understand. “Initially the rule seems to have been that two sample engines must each have had twice the time operating without failure as the operating time of the engine to be certified (rule of 2x).” This rule specifies that every sample engine in the rocket must operate without any difficulties for twice the time at the failure time. NASA used the engines with the most trials in order to have a safe flight. However they did not take to considerations that at the time they used the engine, it might fail for the first time. Engineers did not have to use the engine that had the most successful trials but used a similar sample that would have the same low probability of failure. 2. 3 Avionics

The avionics is like the brain of the rocket. Every single data collected from the atmosphere like temperature, and pressure is recorded to the computer. One of the most important tasks of the computer is being in charge of the automatic ascending and descending. After the command is recorded in the computer, it also shows the stability of the process to the astronauts. The main computer consists in four other smaller computers that will make the decisions. In order for a decision to be made, the four computers must have the same decision. “If one of the computers disagrees, or is too late in having its answer ready, the three which do agree are assumed to be correct and the errant computer is taken completely out of the system.”

This shows how the computers have an important control on themselves. If one of the computers does not agree with the decision made is taken out of the program. The computers trust in each other because they have the same program and should work together. There is a bigger chance to have a successful flight when all the computers have the same decision. When two computers are left they control the rest of the flight. The program is used since it was introduce for the first time. The program is so complex it would take a lot of time to create a new program that would work the same way. In order to maintain the good work in the software it needs to be checked carefully. If an error is found in the program it would be fixed immediately by basic programming. The software is the most important part in the rocket. If the software fails during the flight it would be almost impossible for the astronauts to fix it.

3. Faulty Oil Rings
Reports show that the cause of the accident was a technical failure in the O-rings of the shuttle. A cause for the faulty oil rings was the temperature at which the rocket was launched at. Before the Challenger Shuttle launch, there was twenty four previous successful launches made by NASA, who would have thought that the twenty fifth would be a failure. The coldest launch temperature out of those twenty four launches was fifteen degrees Fahrenheit warmer than the temperature at which the Challenger was going to be launched at. O-rings with warmer temperature go back to their original shape faster than colder O-rings, therefore making the shuttle’s O-rings leak and create a flame with the shuttle’s gases at the time of the ignition. The obvious cause of the accident was a technical failure but there are other factors that led up to this technical milestone in history. 4. Preventive Measures for the Future

If the Challenger mission had preventive measures, the whole incident could be avoided. Some of the measures that engineers needed to take in considerations demanded by this flight: better equipment maintenance of the space shuttle, take more time to check if everything was working at one hundred percent effectiveness, more communication between engineers, and more safety measures. If the Challenger equipment had maintenance thought the process, the solid rocket motor problem had been avoided. Some parts of the Challenger were not working at one hundred percent because the solid rocket booster was used before in previous flights.

The solid rocket booster was used before but the primary problem was the O-ring that was not sealing perfectly, which produce leaks that help escape hot exhaust and reach the O-ring. If engineers had better communication between them, this problem could be avoided because engineers knew this problem. As mention by Neuner and Rider, “Engineers knew that the blow holes were a concern, but they continued to do the high pressure test. They thought that the holes were less of a threat than if the primary O-ring was faulty or flawed in any way.” (p. 4) For future space shuttle flights, more safety precautions are needed to be made to prevent catastrophic disasters. In conclusion, all the preventive measures needed to be done before the launch. This would prevent the disaster from happening and the seven brave astronauts’ lives had not taken in vain.

4.1 Presidential Commission Report
Being considered the Challenger disaster, there were several recommendations being made by the commission. Some of these recommendations addressed by the commission were: solid rocket motor design, shuttle management structure, critical item review and hazard analysis, safety organization, improved communications, landing safety, launch abort and crew escape, flight rate, and maintenance safeguards. The presidential commission reported all these recommendations in order to guarantee a safest flight.

Solid rocket motor design commission recommendation included a team of twelve people, six coming from NASA and six from outside of NASA. The team worked on designing a more solid design for the rocket motor. This team had to design a whole new rocket motor and redesign the actual rocket motor with alternatives that made the redesign rocket motor with improved quality and safer error free operation. The second recommendation made by the commission was shuttle management structure. What this involves is the administration assigned Sam Phillips to analyze the management of NASA’s programs. Critical item review and hazard analysis was a recommendation to completely review all failures and analyses associated with CIL. The team would have to resubmit all waivers to be reviewed so they can be reaccepted.

With improve communications, the communication will be effective redesign and all the NASA activity information will be available at its headquarters. Landing safety was needed to be review because all the precautions needed to land safety will be considered for redesign. Tires, brakes, and steering system would be analyzed for an improved performance and more effective. Launch abort and crew escape was an excellent recommendation the commission could have mention. With this in mind, the Challenger disaster could be avoided or just avoided the dead of the astronauts. Flight rate means that there would be a flight crew that would be trained with software delivers that would certificate astronauts. A maintenance safeguard is the last recommendation mention by the presidential commission, which is important along with all the recommendation mention above. With maintenance safeguard there would be a less probability that the shuttle will malfunction like the Challenger. Maintenance is expensive to do, but it would maintain every aspect of the shuttles in perfect working conditions. This will conclude with safer and befittingly flight.

4.2 Recommendations of the Presidential Commission
After conducting an investigation of the Challenger accident, the commission determines recommendations that will make a safe flight. The Presidential Commission Report (1986) stated the following: The faulty Solid Rocket Motor joint and seal must be changed. This could be a new design eliminating the joint or a redesign of the current joint and seal. No design options should be prematurely precluded because of schedule, cost or reliance on existing hardware. (p. 34) According to this, the solid rocket motor joint is the number one thing that was needed to redesign. This is because this was the primary cause of the Challenger disaster was the impairment of the solid rocket motor joint. This is one of the recommendations made that most people believe is the most important of all recommendations made by the presidential commission. In conclusion to all the recommendations of the presidential commission, they conclude, “Commission urges that NASA continue to receive the support of the Administration and the nation” (Presidential Commission Report, 1986, p. 38). If both parts help the NASA giving them all the support necessary, NASA would had been beneficial because of all the confidence they will have. All recommendations would help in the long run NASA with future successes of upcoming space shuttles.

5. False Confidence
Having come from so many successes in launches, NASA had reached a point in their work that they felt they were perfect. “Success breeds confidence and fantasy.” This statement is a key factor as we look into the causes of failure for the launch of the Space Shuttle Challenger. With so many positive results in their previous projects, we notice that NASA became comfortable with their work. This resulted in the failure we saw in the Challenger disaster. How can an organization as grandiose as NASA become complacent? NASA being the technology giant that it was had failures with an issue that they knew was a problem. The issue with the “O” Rings was recurrent in their testing, they realized time after time that there was some kind of issue but were unsure of the cause and its potential risk. In their preliminary testing we see how the analysis of these “O” Rings resulting in a Criticality of 1R.

These classifications denoted the following, “1,” that joint failure could cause a loss of life or the loss of a shuttle; the R denoted that the secondary “O”-Rings provided redundancy. After some further minute reviewing they removed the R and just considered it a potential loss of risk without redundancy. This was because the secondary “O” ring was no longer a redundancy but and actually a critical part of the system. This leads us to question not the issue with the “O” Rings but the decision making within NASA. This is best described as negligence. Although there was the reviewing of the issue, there was still substantial evidence to lead to further research of the “O” Rings. As stated before we reach the understanding on how NASA felt confident in their previous endeavors and therefore resulting in false sense of confidence to carry out the launch. It is important to note that it was not all of the staff at NASA that disregarded the issue.

6. Fundamentals of Systems Engineering
6.1 Engineering ethics
“Engineers are responsible for their actions to the engineering community, to political and societal institutions as well as to their employers, customers, and technology users.” Engineering ethics, a simple but essential part of engineering that was taught to us in Fundamentals of Engineering class, was not abided by in the developmental phase of the Challenger Shuttle. The Thiokol engineers clearly had a tremendous amount of responsibility with the community, with NASA, the astronaut’s families and even with the United States of America. Unfortunately they did not take full responsibility when trying to explain to the Rogers Commission that the oil ring’s temperature was a factor not to be ignored. During in a meeting the same morning of the launch, Thiokol engineers gave up when they saw that the information given was not getting through to the audience.

“I made the statement that if we’re wrong and something goes wrong on this flight, I wouldn’t want to have to be the person to stand up in front of the board of inquiry and say that I went ahead and told them to go ahead and fly this thing outside what the motor was qualified to.” Allan McDonald, Thiokol Engineer. In our point of view one of the most crucial factors in this disaster was the ethic of the engineers in charge of the design. The responsibility of the design engineers was to keep the design flawless of any kind of error. The pressure that the company in charge of the design had did not help in completing the project flawless. The rushed schedule make it seemed like if the managers didn’t even cared about the astronaut’s safety. The day before the launch was schedule, the engineers held a teleconference with managers recommending against launch. The managers from MTI agreed to postpone the launch, but that just lasted for a little while, thanks to the pressure from NASA managers, that were only focus on reputation, money and the time as priorities.

As we can see in this memo the company in charge of the design knew exactly the risks and they let the managers at NASA know what could happen. At the end of the decision the company was almost forced to vote yes on the launch regardless of everything that they knew. If the ethics of this engineers and managers were a different the disaster could of have been avoided. Not everything in this disaster was bad, because of this tragedy, the NASA and the discipline as a whole changed drastically their ethics so that nothing like this could happen again.

6.2 Modeling and Design
If the Thiokol engineers had followed the design review cycle, which was learned in this semester’s Modeling and Design Systems Engineering class, and had focused on the design for safety, then their shuttle, would have been a success. The design review cycle is displayed as a flow chart in this page. Going down the chart we could see that if the challenger engineers had seen that the recommendations for product improvement (the shuttle) were not approved, then they would have to hold special review meetings to discuss alternatives.

Unfortunately, “the public is more familiar with bad design than good design. It is, in effect, conditioned to prefer bad design, because that is what it lives with; the new [design] becomes threatening, the old reassuring.” Paul Rand. Instead, when trying to explain to explain about the oil ring faults and that temperature was a factor not to be ignored to the people that cleared the shuttle to launch, the engineers gave up when they saw that they were not getting through to the audience. They tried explaining once more with pictures but the audience was negligent to the fact that the O-rings were faulty. The fault of the accident was not only the engineers but also the Commissions for not being aware of the consequences after they had been presented to them.

Researchers have called this tragedy a “State-Corporate Crime”, but in reality it is the fault of a system that was pressured way before the developmental phase. The saying, “The Devil is in the Details”, is accurate for the Challenger operation and system design. Before the accident even happened, NASA and the system’s engineers did not fully understand the details of how the O-Ring’s joint seal fully worked. They played a, “kind of Russian roulette. … (The Shuttle) flies (with O-ring erosion) and nothing happens. Then it is suggested, therefore, that the risk is no longer so high for the next flights. We can lower our standards a little bit because we got away with it last time. … You got away with it, but it shouldn’t be done over and over again like that.” The “devil” was definitely in the way of thinking of the engineers during the designing phase of the Challenger shuttle.

7. Conclusion
Not only did the challenger shuttle have bad communication in the design process, horrific engineering ethics, but it also had tremendous pressure from NASA itself which led to a faulty design and eventually a tragedy. Before the Challenger accident NASA had planned to send a mission a week after a successful mission had been accomplished in 1982. A second plan was made in 1985 that there should be twenty four successful missions a year by 1990. Unfortunately there was realization that NASA would barely be able to send two missions a month to space. By the time the Challenger Mission was beginning to be designed there were only a handful of successful missions launched which did not meet any of the two previous plans. Therefore, NASA pressured the engineers and themselves to send the Challenger up to space as soon as possible regardless of its faulty design.