72 Engineering Ethics: An Industrial Perspective
gases had blown by the primary seals on two field joints and had produced
large arc lengths of blackened grease between the primary and secondary
seals. Based on this discovery, he hypothesized that the low ambient tempera-
ture (resulting in a 53° F O-ring temperature) prior to launch caused reduced
O-ring resiliency, which was responsible for the excessive blow-by. Further
O-ring bench testing confirmed his hypothesis. Boisjoly became part of the
Thiokol O-ring investigation task force formed in August 1985 (Boisjoly,
The night before the launch of Flight 51-L, because of Thiokol’s con-
cern that the launch would occur at temperatures in the low twenties,
Thiokol scheduled a teleconference between Thiokol and NASA shuttle
personnel at the Kennedy Space and Marshall Space Flight Centers.
During this teleconference, Boisjoly presented his O-ring data, and
Thiokol management recommended that the launch not occur until
O-ring temperature reached at least 53° F, which was the lowest temper-
ature of any previous flight. George Hardy, the Deputy Director of
Science and Engineering at Marshall, was reported to have been
“appalled” by Thiokol’s recommendation (Rogers Commission, 1986)
but could not launch over the contractor’s objection (Boisjoly, 1987).
Immediately thereafter, while NASA asked for a private caucus, Thiokol
managers attempted to make a list of data to support a launch decision.
The Thiokol engineers witnessed Senior Vice President Jerry Mason ask
Vice President of Engineering Bob Lund to “take off his engineer hat
and to put on his management hat” (Rogers Commission, 1986; Boisjoly,
1987). When the three groups reconvened their teleconference, Thiokol
stated that although temperature effects were a concern, data were
inconclusive, so a launch was recommended.
The temperature data of flights with O-ring incidents, which were
presented by Boisjoly at the teleconference, are shown in Figure 5.3. When
all flight data are added to the plot, including flights with no erosion or
blow-by (see Figure 5.3), it becomes clear that reduced O-ring resiliency
had occurred in every flight associated with a joint temperature less than
65° F (Rogers Commission, 1986).
After Boisjoly testified at the shuttle presidential commission, he expe-
rienced a hostile work environment at Thiokol. He was given an extended
sick leave and then long-term disability for 2 years (Boisjoly, 1987). In
1988, Boisjoly received the American Association for the Advancement of
Science’s Scientific Freedom and Responsibility award “for his exemplary
and repeated efforts to fulfill his professional responsibilities as an engi-
neer by alerting others to life-threatening design problems of the
Challenger space shuttle and for steadfastly recommending against the
tragic launch of January 1986” (AAAS, 2005).
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