9th April 2015
Get Your Priorities Straight
The losses of the space shuttles Challenger in 1986 and Columbia in 2003 dramatically illustrated the risks involved in the human exploration of space, and provide starkly instructive case studies in the ethics of science and technology. One of the main objectives of NASA is the human exploration of space. As a result of this commitment to human space exploration, the shuttle program is ethically and politically acceptable to the extent that NASA promotes careful and honest examination of the risks and safety of those involved. NASA’s examination is something that cannot be done just once. It is NASA’s duty that as flight experience accumulates, they must continue to monitor risks and ensure the safety of all participants. NASA’s shuttle design exemplifies its balance in safety and performance and an understanding that the flight must safely meet performance requirements. In other words, the shuttle’s flight must perform as predicted, not merely return safely. After examining both disasters, it was found that NASA shortened the examinations of risk by deeming the shuttles “operational.” It is well accepted that the tragic destruction of the Space Shuttle Challenger in January of 1986 was the result of organizational failure. Also, the surprising break up of the Space Shuttle Columbia in February of 2003, nearly 17 years to the day after hazardous systems and organizations.
In 1986, William Rogers, an experienced politician, was appointed as the head of the commission charged with investigating the Space shuttle Challenger explosion. The investigation concluded when physicist Richard Feynman dunked a piece of the rocket booster’s O-ring material into a cup of ice water. The material lost its entire resiliency as a result of the low temperatures, thus proving the technical cause of the explosion. During the three nights the challenger spent on the launch pad in cold temperatures an O-ring on one of the rocket boosters had become frail. Roughly a minute after takeoff, hot gas exited one of the boosters and entered the primary fuel tank causing the explosion that destroyed the Challenger.
What many people are unaware of is the conversation that occurred the night before the launch. The morning on the 28th had been particularly cold, with temperatures close to 31 degrees Fahrenheit, the minimum temperature allowed for launch. The low temperature brought up concerns from engineers at Morton Thiokol, the manufacturers of the Space Shuttle's Solid Rocket Boosters. They were concerned about the effects of the cold weather on the space shuttle's rubber O-rings, which prevent hot gases from escaping the joints in the shuttle's rocket boosters. On previous shuttle missions, cold weather had caused the O-rings to fail, allowing hot gases to escape. The engineers felt strongly about their concerns and expressed them to Thiokol management, who decided to hold a conference call with the Kennedy Space center and Marshall Space Flight Center. The engineers had minimal time to prepare a convincing presentation because the fueling began for the shuttle around midnight before the launch. Although this very dangerous problem had occurred multiple times before, NASA and Thiokol management believed that because all of the past shuttle missions had been successful, the cold temperatures and a burn-through would not be an issue and the launch could continue as planned.
On February 1st, 2003, Space Shuttle Columbia disintegrated over Texas during its return to Earth. Following the incident an independent investigation led by Admiral Hal Gehman was formed. The root of the crash of the shuttle can be traced back to its takeoff. On January 16th, 2003, about 81 seconds after takeoff a briefcase-sized piece of foam broke off the Space Shuttle Columbia. The foam came from the main fuel tank and hit the left wing of the shuttle. Considered the velocity the shuttle was traveling, the foam was able to damage the left wing enough to cause part of the Shuttle’s Thermal Protection System tiles to be compromised. Upon re-entry into the Earth’s atmosphere the extremely hot plasma that the shuttle creates as it slows down intensified the damage to the left wing. Eventually, the left wing became pierced, allowing plasma to enter the wing. As a result, the wing sensors began to fail and the on board computers could not correct the increased drag from the damaged wing. Inevitably, Columbia lost aeronautical control and became ballistic at a speed near 20,000 kph. Unfortunately, all seven crewmembers were killed in the crash. Similar to the O-rings on the Challenger, this was not the first time foam had detached from the main tank and caused damage to the shuttle. On previous flights there had been numerous impacts by pieces of foam smaller than the one that hit Columbia. It was normal for shuttles to return with impacts. There are numerous reports in the Problem Reporting and Corrective Action (PRACA) system that show thermal tile damage as a likely result of foam shedding. The Thermal Protection System on the shuttle was not designed for the possibility of foam shedding. Also, the high level engineering requirements of the shuttle state that nothing should impact it during launch. Chemists and engineers declared that the foam shedding did not pose a flight safety risk. They based their studies on the small pieces of foam that had broken off on previous flights. However, they did not consider the damage a larger, briefcase-sized piece of foam could do. This type of foam shedding was uncommon, much like the three days of abnormal cold before the Challenger launch. Engineers were concerned that the debris that impacted Columbia could have impacted near the landing gear housing. They thought that if they could see the damaged area using telescopes or satellite images they could best assess the situation. If the wheelhouse had been damaged it was possible none of the land gear would be deployable upon landing. NASA’s upper management shut down the image request claiming the foam did not create a flight safety risk. This is an example of the hierarchical and bureaucratic structure of NASA. This can also be seen in the Challenger launch decision and directly conflicts with the intuitions of NASA engineers. After the crashes of Columbia many people asked themselves how this could be happening again. Sally Ride stated in an interview, “There are many parallels. Not so much between the accidents themselves, but between some of the organizational contributing causes to the accidents.” Indeed there are a number of parallels between the two crashes that suggest NASA needs to make significant changes in its organizational structure. Misunderstood anomalies were seen as the root cause in both of the crashes. Anomalies in performance, if followed by a successful landing, were considered evidence of safety instead of what they really were, evidence that the shuttle did not perform as designed. In other words, safely landing after foam shedding or seal erosion reinforced the belief the shuttles were safe when they were not. This acceptance of shuttle not performing as designed by NASA violates the trust given to NASA to accomplish human space travel safely. Override concerns from engineers proved to be another parallel amongst the two crashes. In both cases qualified engineers who knew the most about the relevant systems expressed concerns that could have averted the disasters. Unfortunately their concerns were overridden in both cases. With regard to the Challenger, the engineers of the rocket boosters expressed their desire to wait for a warmer launch day. NASA officials were frustrated and wanted to launch so naturally the engineers were overridden. Why did this happen? This could be because the O-ring was issue was not large concern or because there was pressure from the White House because President Reagan wanted to use the successful launch in his State of the Union Address the following night. With regard to Columbia, engineers felt that the impact of the foam shedding could be more significant than previous launches. They requested a damage assessment but for some reason were overridden. Had management accepted the request the disaster could have been averted. NASA has gone from launching a shuttle based on a system being safe to launch based on design to a process assuming launch and requiring anyone asking for delay to prove it to be unsafe. It is as if NASA’s number one priority is no longer safety. Dan Goldin, NASA administrator from 1992 to 2001, had a mantra, “Faster, better, cheaper.” Considering they are conducting human space flight it would make sense to have safer in that mantra as well. This gave the impression that budget and schedule is the most important thing to NASA. This is evident in both the Challenger and Columbia space shuttle launches.
The organizational failures highlighted by the Columbia ad Challenger tragedies show serious changes need to be made to NASA’s human spaceflight program. Sally ride stated she “hears echos of the Challenger” in the Columbia investigation. When these problems persist over a period of time, with a change in personnel, it means that something methodic is going on. There are a number of steps NASA needs to take before it can begin planning another space shuttle launch. Safety and performance as designed should be their number one priority.