Very early in the Challenger investigation Allan McDonald realized that he must keep extensive notes of the day-to-day happenings, because the question of personal liability could arise someday. Those notes became the basis for this book and his care for details are clearly shown. This is a “must-read” book for anyone who wants to become familiar with the Challenger accident and the subsequent recovery effort to return the space shuttle to flight. The book is long at nearly 600 pages, but for me it went by fast, because I was an engineer in Mr. McDonald’s engineering organization at Thiokol during those troubled years. I’m a slow reader and yet I still finished the book in about 2 weeks. Quite often, I would ask myself I wonder if so-and-so will be in the book and sure enough that person was on the next page.

If one is only interested in the pivotal night before the Challenger launch, they will get that important part in the first 9 chapters or about 124 pages of the book, but there is a lot more to the story than just that. There is the story of the investigation, the redesign effort, and the return to flight and all the twists and turns that occurred along the way.

Initially, NASA wanted to defuse the situation and not rush into the blatant problem of the critical o-ring erosion in the solid rocket motor joints.   This was a problem that was known to hundreds of engineers at both Thiokol and NASA, who were working hard to solve it. Allan McDonald saw the management diversion in both NASA and Thiokol from discussing the O-ring problem and spoke up against it and yet the diversion still continued. Recognizing the problem in the early investigation and the errors involved in skimming over the temperature sensitivity of the O-rings to cold temperatures was not only a matter of being forthright, but also a matter of key importance in returning to flight in a timely matter. To me the return to flight would have been a lot longer, if it hadn’t been for engineers like Allan McDonald focusing quickly on the O-ring problem and the need to address it.

As the recovery effort was started to redesign the rocket motors joints, there were many issues, strategies, and problems to deal with. A good integrator at the top of an engineering organization must be aware of all the issues and know how to direct and delegate engineers to look at them without loosing a stride.   Mr. McDonald, who was promoted to the Vice-President of Engineering for the recovery effort, was just such a person. One idea that occurred to him was to look into the possibility of having an analyst reconstruct a convective flow model to predict what the joint temperatures were on that fateful morning of the Challenger accident. To build a Computational Fluid Dynamic (CFD) model to predict the pre-launch environment to include the wind, the cryogenics venting, heat transfer, solar heating, and buoyancy convection for the entire launch vehicle and facilities would be a formidable task. However, it would be a very interesting task, because there was a controversy about how cold the pre-launch joint temperatures were. On launch day photographs on the Florida launch pad under the shuttle showed icicles hanging from the understructure like a cold winter day in a northern city. Early in the analysis NASA discouraged this line of thought, but ultimately NASA and Rockwell conducted CFD models that confirmed the Thiokol analysis that cold temperatures did exist at the joint locations.

There were many twists and turns along the way to return the shuttle to flight. Early on there had been efforts by management to move Mr. McDonald and others aside for not towing the company line. Such potential efforts had been thwarted in a way that Allan McDonald only later learned after the fact. In August 1986 Congressman Markey (Democrat from Massachusetts) called Allan McDonald to ask him how things were going. After saying things were going well in the redesign activities the conversation turned to whether Allan had received a copy of the letter that he had sent to Mr. Charles Locke, Thiokol’s CEO. Mr. McDonald replied that he had no knowledge of such a letter. The Congressman then sent Allan a copy of his letter to Locke dated May 19, 1986 that referred to House Joint Resolution 634 (dated May 14, 1986) along with a copy of the resolution. In effect the letter and resolution stated that Thiokol would be disqualified from any future contracts with NASA in the advent that employees were reassigned because of their testimony before the Presidential Commission investigating the Challenger accident. And so, in effect congress had acted as guardian angels behind the scenes insuring that Mr. McDonald would have an important role in the recovery effort.

Controversies did not come to end, even with the return to flight. On a post-flight inspection shortly after the shuttle returned to flight many damaged Orbiter tiles were found. Immediately, attention returned to Thiokol as the main culprit with the Solid Rocket Booster (SRB). This time loose SRB insulation cork was blamed as the falling object that was hitting the Orbiter during ascent. This was a grave concern, because damaged tiles could cause a major failure during the shuttle re-entry.   In the subsequent NASA Flight Readiness Review (FRR) all eyes were focused on Thiokol. However, Allan McDonald pointed out that there were other sources of falling debris including the External Tank (ET). It was the ET falling debris that would eventually cause the fateful Columbia accident.     

Twenty-five years have passed since the Challenger accident. Those engineers and managers that were there during the time of the crisis are moving on in years. Many for some reason have not written their memoirs. There are few that were as close to the scenes as Allan McDonald and probably fewer that kept such extensive records. In all likelihood there will not be another personal account about this tragic accident that is as accurate and riveting to read ever again.