Did History Actually Teach Us Anything? - Episode 21 Space Shuttle Challenger Disaster (1986)


Laura: Welcome to "Did History Actually Teach Us Anything?".
The podcast where we unravel the most well-known tales of calamity, mishap, and unforeseen consequences that have shaped the course of history, and consider whether we've actually learned anything from them all these years later... 
In this podcast, we examine the historical events that you may think you know about already and the causes that led to them, be they icebergs or bakers ovens. 
We will consider whether these tragedies could have been avoided, and some of the surprising things we do differently now as a result. 
But this podcast isn't just about dates and events. It's about learning from the past, drawing insights from hindsight, and gaining a deeper appreciation for the complexities of what really happened in these events we think we know so well. So get ready to encounter remarkable individuals, pivotal moments and fascinating insights that will make you appreciate health and safety and environmental management as far more than just red tape. 

It is shocking to see people lose their lives in a catastrophic event. It's equally shocking to find an organisation that has the technology to put astronauts on the moon also has management systems that are so routinely violated that it has become the norm for their institution. 
This episode on the Space Shuttle Challenger Disaster of 1986 is not just about the loss of life on that fateful day; it is also about the normalisation of deviance that desensitised the organisation to the risks faced by the crew as they prepared themselves for the journey of a lifetime. 
Joining us on this episode is Kevin, who is going to give us a brief introduction to the Space Shuttle Challenge disaster and explain where this all began... 

Kevin: Imagine, if you will, the excitement at Cape Canaveral just before midday on the 28th January 1986. The launch of the Challenger shuttle was about to take place. Its mission: to put a second tracking and data relay satellite (or TDRS) into orbit, but also to launch the Spartan Halley spacecraft, which was to observe Halley's Comet during its closest approach to the sun. This was Challenger's 10th mission. 
Challenger's launch have been delayed by several days at this point because of problems getting the previous shuttle mission back onto the ground, so tension was high in the control room. To make matters worse, a severe cold weather front swept through the central Florida the night before and left a layer of thick ice on the launch pad. Everyone had their fingers crossed for a successful launch.
And what about the Challenger crew? How might they be feeling at this point? Relieved that the mission was finally "a go"? 
The crew was made up of 7 astronauts representing a cross-section of the US population, including a teacher, who had been the winner of a national screening program and would conduct several lessons whilst in orbit and then partake in a nine month lecture tour around the US.
This had attracted significant media attention, so the take-off was being live streamed on television. The eyes of a nation were fixed on Challenger, including many school children. 
What could possibly go wrong?!

Laura: So Kevin, can you tell us a bit more about the construction of the Challenger and its launch on the 28th January 1986? 

Kevin: Construction of Challenger started in November 1975, and it was originally intended to be a test vehicle. It was put through 11 months of structural testing in a specially constructed rig, which could put the shuttle through all phases of flight from lift-off to landing. However, computer models of the time were not sophisticated enough to be able to calculate the stresses put on the shuttle during the various stages of flight.
Between 1979 and 1981 Challenger was converted from a test vehicle into a spacecraft. Its first launch was due to take place on 20th January 1983 and was to release the first TDRS into space. A series of problems with both Challenger and the TDRS meant that the launch finally took place on the 4th April 1983.
Not only was the satellite released, but two of the crew executed the first spacewalk of the shuttle program. TDRS later became part of a series of satellites used by astronauts to stay connected with controllers back home.
Challenger reached many other milestones, including achieving the first night launch and landing, and the first operational Spacelab flight. This was a European space laboratory that could fit into the shuttle's cargo bay and included several experiments that were designed to be carried out in microgravity. The April 1984 mission featured the first astronaut repair of a satellite.
Not only was Challenger involved in executing milestones in space technology, but also hosted several cultural firsts in the space shuttle programme: the first female US astronaut in June 1983; and the first black astronaut in August 1983. In 1984, two female astronauts flew on a mission together for the first time, along with the first Canadian astronaut.
Having already completed 9 successful missions throughout 1983, 1984, and 1985, hopes were high that mission 10 would be just as successful, despite the initial setbacks.
Concerns have been raised by some of the engineers as to the integrity of the seals on the solid rocket boosters in the extremely low temperatures experienced on the morning of 28th of January 1986 but, nevertheless, the launch countdown commenced at 11:38am.
Everything appeared to be proceeding as normal, until Challenger emerged from "Max-Q", which is the period of greatest aerodynamic pressure during liftoff.
Within a few seconds of the engines firing and clear the launchpad, the command was given to "go at throttle up".
A few seconds after this command, the Challenger pilot was heard to say "uh-oh" and then all communication with the shuttle was lost. On the ground, flames were seen on either side of the solid rocket tanks.
At an altitude of 14,000 metres and only 73 seconds into lift-off, Challenger disappeared in a fireball and broke apart.
As the full horror of what they had witnessed sank in, the nation sat in stunned silence. Watching school children and the families of the crew couldn't understand what could have happened.
The forward section, containing the crew cabin, was severed from the body of the shuttle, and, after continuing upwards to a height of 65,000 feet, then plummeted intact into the ocean. 
All 7 of the crew died. Although they were likely to have survived the initial breakup of the shuttle, the crew cabin was not pressurised, and so it's believed that the crew would've died due to oxygen deficiency.

Laura: So what happened in the immediate aftermath, and what action was taken by NASA after the disaster? 

Kevin: NASA immediately suspended the shuttle programme until a full investigation had been carried out and President Ronald Reagan, who would've been undertaking a planned State of the Union address to the nation that evening, was instead left to express the shock and sorrow of the nation on witnessing the horror of the disaster on live television.
Debris from the disaster rained down on the Atlantic Ocean for more than an hour after the explosion, and salvage crews were dispatched to collect the wreckage for investigation and to recover the bodies of the crew. Unbelievably though, the solid rocket boosters had righted themselves after the explosion and had continued flying, so NASA was forced to detonate charges 30 seconds later to stop them from flying and causing damage when they finally dropped to earth. 
NASA carried out its own intensive investigation and a commission appointed by the President was undertaken, chaired by a former Secretary of State, the report of which was presented to the president on 6th June 1986.
During the initial stages of lift-off, there had been no visible signs of problems. All systems had been operating normally, including communications with the crew, and there had been no alarms sounding in the cockpit. This meant that the crew were not aware of any problems until the flames had been spotted by the pilot just before the fuel tanks ignited.
Although NASA originally believed that the Challenger had exploded, it was discovered that a seal, called an "O-ring", on the shuttle's right solid-fuel booster, which was designed to prevent fuel leaks during lift-off, had failed due to the extremely low temperatures. Hot gas began pouring out the tank, causing it to collapse and tear apart. The resulting flood of liquid hydrogen and oxygen into the atmosphere, and fragments of the fractured solid fuel tank, ignited the main fuel tank and this created the huge fireball viewed by the watching public.
On reviewing the camera evidence after the incident, there had been visible signs of plumes of smoke from around 60 seconds after lift-off, but at that point in the process there would've been no survivable abort options for the mission or anything that either the crew or the ground controllers could have done to stop the catastrophe from unfolding.

Laura: What were the main findings of the Presidential commission into the Challenger disaster? 

Kevin: The consensus of the commission was that the incident had been caused by the failure of the "O-ring" on the joint between the two lower segments of the right Solid Rocket Motor. There was no evidence of the failure of any other elements of the shuttle system or any evidence of sabotage.
The commission found that the failure of the "O-ring" was due to faulty design, which made it unacceptably sensitive; including to the effects of temperature, distortion effects from being reused, and the reaction of the joint on the solid fuel tank to dynamic loading during lift-off. 
The commission also found that the decision to continue with the launch was flawed, because the people who made the decision were not aware of the identified problems with the "O-ring" - particularly its high sensitivity to extreme cold. 
There were failures in communication based on incomplete and even misleading information; a conflict between engineering data and launch management decisions; and a NASA management structure that allowed internal flight safety problems to bypass key Shuttle project management personnel.
If there had been a well-structured and managed system, emphasising safety, this would've flagged up the rising doubts about the Solid Rocket Booster joint seal, which would in turn have led to them being emphasised in the flight readiness process. Had this been the case, the launch would've been postponed.
NASA's safety program was no longer effective and had become almost redundant at the time of Challenger's launch. No safety representatives were involved in any of the launch decisions. There were also issues with the safety programs with other organisations involved in the manufacture of the shuttle boosters.
NASA's efforts to streamline shuttle operations to achieve its stated goal of flying 24 missions per year had been too ambitious. The shuttle program did not have the resources of personnel or spare parts to achieve this without straining its physical resources and overworking its technicians. Safety, reliability and quality assurance also suffered, adversely affecting mission safety.
In fact, when flights are so close together, there is insufficient time to ensure that critical problems occurring during one flight are identified and addressed before the next flight takes place. There had been an assumption that Challenger could survive any minor mishaps and NASA continued to push it further, trying to accomplish too much with too few resources.
The commission also concluded that the freeze protection plan for the launch pad was inadequate. The extreme cold and presence of so much ice on the structure should have made it inadvisable to launch that day, and margins of safety were reduced far too low. Had it been necessary to evacuate the shuttle on the launch pad for any reason, the crew would've been running on an icy surface, so they should have been made aware of the risk and greater consideration should have been given to delaying the launch completely.
NASA was not the only organisation criticised by the commission report. The manufacturer of the shuttle boosters, engines and tanks, and their contractor, who manufactured the booster motors, including the "O-rings", were both criticised. 
It was felt that the contractor had "given in" to pressure from the shuttle booster manufacturer to reverse its position on delaying the launch, to accommodate NASA's requirement to proceed. The shuttle booster manufacturer was criticised for keeping problems to itself and trying to resolve them internally, rather than making NASA aware of them.

Laura: So, could the tragic outcome of the Challenger disaster have been different, particularly regarding the crew's fate?

Kevin: Separation of the crew cabin from the main body of the shuttle deprived the crew of oxygen, except for a few seconds that would've remained in the supply lines. Each crew member had a personal egress air pack (or PEAP), which was connected to their helmet and contained an emergency supply of breathing air. However, this needed to be manually activated to be available and would only last for around 6 minutes. 
Of the 7 PEAPs on board, only 4 were recovered, of which 3 had been activated. It would've been an automatic response by the crew to activate the PEAPs if there was a drop in cabin pressure. However, it's believed that the remaining PEAPs were not activated because the crew lost consciousness rapidly and did not regain it before the crew cabin's impact with the ocean.
It is estimated that the total amount of time the crew cabin was in free-fall was only 2 minutes and 45 seconds, and then it hit the water at 207 miles per hour. Because of the damage caused by the impact, the actual cause of death could only be assumed from evidence remaining in the crew cabin.
The Presidential commission had found that the space shuttle system had not been designed to survive a failure of the solid rocket boosters and there were no corrective actions that could be taken, including an ability for the crew to escape. This could have been due to excessive cost or the location of the solid rocket boosters. However, once the incident was in progress the outcome was unavoidable.

Laura: Taking things further, is there any way the whole situation could have been avoided, particularly relating to the unprecedented cold weather on the launch day?

Kevin: Problems with the "O-rings" had first been identified in 1977 by engineers working at the company that designed them - almost 10 years before that fateful launch day. 
NASA had been made aware of the problem in a report, however the team in charge of the shuttle project ignored the report findings, even after evidence of erosion on the "O-rings" was discovered during earlier shuttle flights.
A design flaw in the "O-rings" meant that they were highly susceptible to low temperatures. When tested after the incident, it was proved that, if dipped into a glass of ice water, the resiliency of the "O-rings" was severely reduced. 
It was surmised that frost forming on the "O-ring" in question on the night before the launch had frozen it and made it brittle. Forces on the "O-ring" during lift-off had opened a crack and this had allowed the jet of hot gas to escape.
Interestingly, no mention was made of the susceptibility of the "O-rings" to extreme cold in any of the pre lift-off briefings (despite the launch being planned for January), even though several checks were made of the ice build-up on the launch pad.
So, if Challenger hadn't been launched on the coldest day of the year, in fact, it was the coldest launch day ever at that point, the "O-rings" might not have failed.

Laura: So, what were the long-term consequences of the Challenger disaster on the shuttle programme and its future? 

Kevin: From the very beginning of the program in 1972, the shuttle had been viewed as a "do-everything" vehicle, carrying every kind of space payload and, therefore, NASA had phased out "expendable" rockets from the programme, such as the Delta and Atlas models. 
Reliance on the shuttle was official national state policy, but the Department of Defence had become concerned about their reliance on the shuttle, even before the Challenger incident, and had started a programme of buying advanced Titan Rockets for its own use.
After the Challenger incident, other groups came forward to express their concerns on their enforced reliance on the shuttle program for access to space, including scientists - whose missions now faced lengthy delays. 
By July 1986, NASA had announced the shuttle would not be ready to fly again until 1988 because Congress had still not decided on whether they would build another orbiter to replace Challenger. It was felt that, in fact, two orbiters would be required to meet the stated launch needs of the 1990s, including construction of NASA's international space station.
Finally, in August 1986, President Reagan announced that a replacement for Challenger, named Endeavor, would be built and construction would start strides away. However, when the shuttle service was finally resumed, it would be restricted to carrying defence and scientific payloads. 
NASA invested over $2 billion in making technical changes. This included the shuttle rocket booster design, including changing the fateful "O-ring", and the basic crew escape system. They also worked to change the safety culture of its workforce and of contracted organisations. The safety programme was changed to include safety representatives and to allow concerns to flow upwards through the organisation, to ensure they were not lost, and to improve communication.
It had long been the goal of the US administration to foster a private space launch industry. Within a few weeks of the presidential announcement on Endeavor, three different companies stepped forward to announce their plans for operating commercial versions of all existing launch vehicles. 
Plans to fly further civilians into space were shelved after the Challenger incident, and it wasn't until 2007 that the next civilian crew member flew on Endeavor. Satellite payloads were no longer taken on the shuttle, and astronauts were no longer required to carry out more dangerous duties, such as repairing satellites, to preserve their safety.
Family members of the Challenger Crew set up the Challenger Center for Space Science Education Programme, which allows students to take part in simulated space missions, thus encouraging the interest of future generations of potential astronauts in the US space programme.

Laura: Although the technical cause was the "O-ring" failure, what were the human mistakes that impacted the outcome of the challenger disaster? 

Kevin: Although the technical cause of the incident was the failure of the "O-ring" in extremely low launch temperatures, serious errors of judgment and lack of communication by key decision makers at NASA was found to be the root cause of the accident by the Presidential Commission. 
Even though there were concerns about launching that day, NASA justified its decision to continue with the launch based on previous successful ones. It is believed that the benefits of launching that day from a public relations point of view might have overruled common sense, but concerns about the reliability of the "O-ring" were not recorded on any of the pre-launch discussions. We must ask why such a critical component would not have been considered. 
There had been a conference call the evening before with the contractor company, expressing concerns about the possibility that the "O-ring" might fail to properly seal the joint on the solid rocket boosters in the extreme cold expected during the launch. There had already been several delays to this launch, and NASA were concerned about the impact of future ones, so overrode the concerns of the engineers. The "O-rings" had worked perfectly well in previous launches, so why would this one be any different?
NASA were under enormous pressure to deliver their stated aims for the shuttle program, to make space available to everyone, and to make this happen within their available budget. So they cut corners, accepted deviations from standard practice, and pushed harder and faster. 
This process is called the "normalisation of deviance" and develops over an extended period, so that eventually, bad practice becomes normal and accepted. The flaw in the "O-ring" was well known but as there had been no incidents previously, the flaw became acceptable. There were also two "O-rings" on the solid rocket boosters, so if one failed the other would act as a backup. What could go wrong?
When engineers raise concerns about the "O-ring" on the night before the launch, they were going against the ingrained cultural belief of NASA of "everything was okay last time, so it will be okay this time as well". The engineers were forced to agree that previous launches had been successful and safe, even though they knew this launch will be different because of the incoming cold wave. This is a mode of thinking called "groupthink". They were part of a team deeply engaged in the shuttle program which overrode their unanimity to remain part of this group. 
The chief engineer who raised concerns was called to give evidence to the Presidential commission about their attempts to delay the launch. Against the wishes of company management, they also produced a copy of a memo written about the "O-ring" 6 months prior to the launch, which was crucial in guiding the commission's investigations into NASA's decision making process. It, however, had an extremely negative effect on the engineer personally, whose whistleblowing was not appreciated by management or co-workers. They eventually became sick and were diagnosed with post-traumatic stress disorder. 

Laura: So our final question is, did NASA learn from its mistakes? 

Kevin: NASA did improve safety, communication and decision-making in the aftermath of Challenger, however there had been further space disasters, such as the Columbia disaster on February 1st 2003, so we are left to ask if they really did learn from their mistakes.
That being said, NASA redesigned the solid rocket boosters to include better seals and insulation to prevent similar failures, and greater attention is now paid to environmental conditions, such as temperature and wind, to prevent risks similar to those that contributed to the explosion. 
NASA also created more formalised procedures to ensure that technical concerns reach decision-makers, and launch decisions now require more robust engineering sign-offs and broader consensus.
Crucially, NASA established a stronger safety culture that encouraged the reporting of potential issues and concerns at all organisational levels, and the Office of Safety and Mission Assurance (OSMA) was created in 1987, the year after the disaster, to oversee safety across all NASA missions.
Now, we will merely look up into the night sky, and, according to the words of Buzz Lightyear, aim for "infinity and beyond", even if only in our dreams...

Laura: Thanks for joining us on this episode of "Did History Actually Teach Us Anything?".
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