As the underwater search began to wind down, the Presidential Commission hearings were also coming to an end.
One cannot help but feel some sympathy for those who testified before the body. In addition to Chairman Rogers, who was a former secretary of state and U.S. attorney general, their questioners included a Nobel Prize laureate and the first person to set foot on another heavenly body.
The majority of those who testified were engineers. Some tried to give a tutorial on how everything worked, others overloaded their testimony with facts. All of them used acronyms. At one point the commissioners characterized their lengthy explanations as “sounding like a filibuster.”
For example, Marshall Space Flight Center Solid Rocket Booster Manager Larry Mulloy testified for more than an hour about the assembly of the boosters, with particular emphasis on the seals and joints. He concluded by describing the complex tests being planned to understand how the joints behaved under the conditions prevailing during the launch of Challenger.
Following a ten-minute recess, Chairman Rogers announced that Physicist Richard Feynman wanted to respond to the presentation.
“Here is a comment for Mr. Mulloy,” Dr. Feynman began. Holding up a Styrofoam cup of ice water, he lifted out a piece of O-ring that he had compressed with a C-clamp. He told Mulloy and the audience, “I took this stuff out of your seal and I put it in ice water, and I discovered that when you put some pressure on it for a while and then undo it, it doesn’t stretch back. It stays the same dimension. In other words, for a few seconds at least, and more seconds than that, there is no resilience in this particular material when it is at a temperature of thirty-two degrees. I believe that has some significance for our problem.” As previously stated, the temperature on launch day had been less than twenty degrees.
Dr. Feynman had just demonstrated that it didn’t take a lot of complex tests to see why the Challenger launch should have been postponed.
Neil Armstrong probably asked fewer questions during the hearings than any of the other commissioners. However, since he was the primary person in charge of putting together the final report, one can conclude that his ideas formed a major part of it.
Years later, he told me that he saw his job in the hearings as gathering information, not expressing opinions. “The final report would do that.” However, Armstrong’s questions were always on target.
During testimony from Thiokol Vice President Robert Lund, Armstrong asked, “One question. Clearly, you had a concern about temperature, and so on. Did you ever consider or take thought of controlling the temperature at the seals, or to changing the material of the seals to something that had different characteristics?”
Lund acknowledged, “Those thoughts have gone through our minds. There has been no positive action along those lines.”
During the redesign that was to follow, that’s exactly what was done. Heaters were installed on each solid motor joint to ensure it never fell below the proper temperature again.
With the help of the testimony, NASA’s own investigation, the contractors, and the evidence harvested from the ocean, the Commission concluded that the accident “was caused by the failure in the joints between the two lower segments of the right Solid Rocket Motor.” They wrote, “The specific failure was the destruction of the seals that are intended to prevent the hot gases from leaking through the joint during the propellant burn of the rocket motor. The evidence assembled by the Commission indicates that no other element of the Space Shuttle system contributed to this failure.” They added, “The failure was due to a faulty design unacceptably sensitive to a number of factors.” Those factors included temperature.
What’s more, the Commission stated, both Thiokol and the NASA solid rocket booster project office at Marshall failed to respond to facts obtained during testing, nor did they respond adequately to internal warnings about the faulty seal design.
Even more critical was this conclusion: “NASA and Thiokol accepted escalating risk apparently because they ‘got away with it last time.’ ”
Commission member Feynman observed in the same section of the report that the decision-making process had been “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.”
In their four-month investigation, the Commission had examined every aspect of the shuttle, from the main engines to the liquid oxygen vent valve in the tip of the external tank, and found they had worked properly. The Commission/NASA team also reviewed every aspect of the prelaunch activities, procedures, and launch decision, along with organizational relationships and interactions.
Their final recommendations touched on almost every aspect of management and operations at NASA and its contractors. The list began with requiring redesign and replacement of the solid motor joint and seal, with independent oversight.
Greater safety underlined most of the recommendations, ranging from improved tires, brakes, and nosewheel steering to a new shuttle management structure that was more accountable to a headquarters manager than a center director. The Commission suggested an independent safety organization reporting to NASA headquarters and the use of more astronauts in safety and other management positions. The new associate administrator for safety would have the authority to stop a launch.
Marshall Space Flight Center was singled out to “energetically” eliminate a policy of “management isolation” that inhibited the flow of information about problems to NASA headquarters and elsewhere.
A complete review of parts and systems in which a single-point failure could result in loss of the vehicle or life was recommended.
Finally, the Commission suggested another look at methods for the crew to escape in an emergency. The space shuttle was the first and only American spacecraft that did not have a crew escape mechanism.
The commission also expressed strong support for the nation’s space program. Their report read: “The Commission urges that NASA continue to receive the support of the Administration and the nation. The agency constitutes a national resource that plays a critical role in space exploration and development. It also provides a symbol of national pride and technological leadership.”
In his transmittal letter accompanying the report to the president, Chairman Rogers stated, “Each member of the Commission shared the pain and anguish the nation felt at the loss of seven brave Americans in the Challenger accident on January 28, 1986. The nation’s task now is to move ahead to return to safe space flight and to its recognized position of leadership in space. There could be no more fitting tribute to the Challenger crew than to do so.”