On the night of January 27, 1986, the prelaunch teleconference involving Morton
Thiokol and the Marshall Space Center was filled with tension. Morton Thiokol
engineers conveyed their recommendation against launching the Challenger space
shuttle the next morning. This recommendation was based on the engineer’s worries
about the ability of O-rings to seal at low temperatures.
Chief O-ring engineer Roger Boisjoly knew the problems with the O-rings all too well.
More than a year earlier he had warned his colleagues of potentially serious problems.
The O-rings were part of the sealing mechanism between the segments of the booster
rockets. If they lost too much of their resiliency, they could fail to seal altogether. The
result would be escaping hot gases, ignited fuel in the storage tanks, and a fatal
explosion.
The technical evidence was incomplete but ominous: There appeared to be a
correlation between temperature and resiliency. Although there was some leaking
around the seal even at relatively high temperatures, the worst leakage was at 53
degrees. With a predicted ambient temperature of 26 degrees at launch, the O-rings
were estimated to be at 29 degrees. This was much lower than the launch temperatures
of any previous flight.
The teleconference was temporarily suspended. The space center had questioned
Morton Thiokol’s no-launch recommendation, and Morton Thiokol had requested the
suspension in order to allow its engineers and management to reassess their
recommendation. The space center would not fly without approval from Morton Thiokol,
and Morton Thiokol’s management would not recommend launching without approval
from its managers.
Gerald Mason, senior vice-president at Morton Thiokol, knew that the National
Aeronautic and Space Administration (NASA) badly needed a successful flight. He also
knew that Morton Thiokol needed a new contract with NASA, and a recommendation
against launch probably would not enhance the prospects of obtaining the contract.
Finally, Mason was aware that the engineering data were inconclusive. The engineers
could not give any firm figures as to the precise temperature at which it would be unsafe
to fly. They were relying on the apparent correlation between temperature and
resiliency and their tendency to be conservative on serious safety O-ring issues.
The teleconference with the space center would resume shortly, and a decision had to
be made. Mason turned to Robert Lund, supervising engineer, and said, “Take off your
engineering hat and put on your management hat.” The earlier no-launch
recommendation was reversed.
Roger Boisjoly was deeply upset by this reversal of the engineer’s recommendation.
As a human being, he no doubt felt concern for the well-being of the astronauts. He did
not want to be a part of something that could lead to death and destruction. More than
this was involved, however. Boisjoly was not only a concerned citizen, but also an
engineer. It was his professional engineering judgment that the O-rings were not
trustworthy. He also had a professional obligation to protect the health and safety of the
public, and he evidently believed that this obligation extended to the astronauts. Now
his professional judgment was being overridden
Boisjoly also did not believe it was appropriate to take off one’s engineering hat in
such circumstances. His engineering hat was a source of pride, and it also carried with
it certain obligations. He believed that as an engineer he had an obligation to render his
best technical judgment and to protect the safety of the public, including the astronauts.
So he made one last attempt to protest the decision to reverse the no-launch
recommendation, pointing out the low-temperature problems to Thiokol management.
He frantically attempted to persuade management to stick to the original no-launch