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opening a gap through which rocket exhaust could escape. As the joints flexed, the rings would come out of their grooves and move to a new position in the joint, a process called extrusion. The extruded ring would form a seal in this new position, but during the time it took for the ring to shift, the joint was unsealed and hot gases could escape, a process called blow-by. These hot gases damaged the rings until the seal was achieved.
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After the disaster, Boisjoly suffered from insomnia, depression, and severe headaches. According to
Boisjoly, Thiokol unassigned him from space work, and he was ostracized by his colleagues and managers. One colleague warned him, "If you wreck this company, I’m going to put my kids on your doorstep."
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Boisjoly sent a memo describing the problem to his managers, but was apparently ignored. Following several further memos, a task force was convened to investigate the matter, but after a month
Boisjoly realized that the task force had no power, no resources, and no management support. In late 1985,
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If the second O-ring had failed, the results would almost certainly have been catastrophic with an almost instantaneous explosion of gargantuan proportions, resulting in the complete loss of the shuttle, the crew and the launch pad facilities seemingly the only outcome. His investigation found that
442:
Boisjoly's investigation showed that the amount of damage to the O-ring depended on the length of time it took for the ring to move out of its groove and make the seal, and that the amount of time depended on the temperature of the rings. Cold weather made the rubber hard and less flexible, meaning
572:
Upon ignition, the O-ring was burned to ash, which formed a weak seal in the joint. At 58 seconds after launch, the shuttle was buffeted by high-altitude winds, the ash seal collapsed, and hot gases streamed out of the joint in a visible blowtorch-like plume that burned into the external hydrogen
548:
protocols required all shuttle sub-contractors to sign off on each flight. During the go/no-go telephone conference with NASA management the night before the launch, Morton
Thiokol notified NASA of their recommendation to postpone. NASA officials strongly questioned the recommendations, and asked
438:
of putty into the joint, forcing the O-ring into its seat. The system never functioned as designed. The rings were supposed to sit in a groove and seal the joint between the sections of the booster. It was found, however, that flight dynamics caused the joints in the SRBs to flex during launch,
676:
webpage. Full text: "For his exemplary and repeated efforts to fulfill his professional responsibilities as an engineer by alerting others to life-threatening design problems of the
Challenger space shuttle and for steadfastly recommending against the tragic launch of January 1986." Retrieved
565:
Historians have noted that this was the first time NASA had ever launched a mission after having received an explicit no-go recommendation from a major contractor, and that questioning the recommendation and asking for a reconsideration was highly unusual. Many have also noted that the sharp
552:
The Morton
Thiokol managers asked for a few minutes off the phone to discuss their final position again. The management team held a meeting from which the engineering team, including Boisjoly and others, were deliberately excluded. The Morton Thiokol managers advised NASA that their data was
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ordered a presidential commission to review the disaster, Boisjoly was one of the witnesses called. He gave accounts of how and why he felt the O-rings had failed, and argued that the caucus called by Morton
Thiokol managers, which resulted in a recommendation to launch, was an "unethical
612:
When
Boisjoly left Morton Thiokol, he took 14 boxes containing every note and paper he received or sent in seven years. On May 13, 2010, he donated his personal memoranda—six boxes of personal papers, including memos and notes from his congressional testimony—to
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was confirmed for
January 28, 1986, Boisjoly and his colleagues tried to stop the flight. Temperatures were due to fall to −1 °C (30 °F) overnight. Boisjoly felt that this would severely compromise the safety of the O-ring and potentially the flight.
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Boisjoly started his career at a used-aircraft company in western
Massachusetts, before moving to California for work. He subsequently worked for companies in California on lunar module life-support systems and the moon vehicle. He later worked for
40:
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the first O-ring failed because the low temperatures on the night before the flight had compromised the flexibility of the O-ring, reducing its ability to form a seal. The temperature at launch had been only
624:
Boisjoly married his wife
Roberta in 1963. The couple had two daughters and at the time of his death eight grandchildren. Boisjoly died of cancer of the colon, kidneys, and liver on January 6, 2012, in
434:
and the rings were intended to seal the joint while allowing for the inevitable movement between the sections under flight conditions. By design, pressure from within the booster was to push a
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Boisjoly wrote a memo in July 1985 to his superiors concerning the faulty design of the solid rocket boosters that, if left unaddressed, could lead to a catastrophic event during launch of a
621:. Rand Boyd, the special-collections and archival librarian at Chapman's Leatherby Libraries, said the materials would be catalogued and archived. They can be viewed by library visitors.
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The concerns of Boisjoly proved correct. Initially, Boisjoly was relieved when the flight lifted off, as he had predicted that the SRB would explode before lift-off.
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tank. At about 73 seconds, the adjacent SRB strut gave way, the right rocket booster crashed into the external fuel tank and the vehicle quickly disintegrated.
458:
Boisjoly advised his managers that if the problem was not fixed, there was a distinct chance that a shuttle mission would end in disaster. No action was taken.
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questioning of the no-go recommendation stands out in contrast to the immediate and unquestioning acceptance when the recommendation was changed to a go.
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274:. He grew up in the neighborhood of Belvidere as the son of a mill worker and one of three brothers. During high-school he played tennis.
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The matter was discussed with Morton Thiokol managers, who agreed that the issue was serious enough to recommend delaying the flight.
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The O-rings were two rubber rings that formed a seal between two sections of the SRBs. The sections of the boosters were joined using
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258:'s managers decided to launch the shuttle despite his warnings, leading to the catastrophic failure. He was considered a high-profile
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After leaving Morton Thiokol, Boisjoly founded a forensic engineering firm and was frequently invited to speak on leadership ethics.
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that extrusion took more time and more blow-by took place. He determined that if the O-rings were damaged enough they could fail.
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inconclusive. NASA asked if there were objections. Hearing none, NASA decided to launch the
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857:"Engineer who warned of 1986 Challenger disaster still racked with guilt, three decades on"
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732:"Coronavirus : faire taire les lanceurs d'alerte nuit gravement à la santé publique"
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in January 1986. Boisjoly correctly predicted, based on earlier flight data, that the
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had failed completely and that damage had been caused to the second O-ring.
423:. During his investigation, he discovered that the first of a system of two
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This memo followed his investigation of a solid rocket booster (SRB) from a
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on the rocket boosters would fail if the shuttle launched in cold weather.
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910:"Remembering Roger Boisjoly: He Tried To Stop Shuttle Challenger Launch"
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Project manager of the solid fuel boosters of the Shuttle Program System
499: in this section. Unsourced material may be challenged and removed.
408:. Such a catastrophic event occurred six months later resulting in the
376: in this section. Unsourced material may be challenged and removed.
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decision-making forum resulting from intense customer intimidation."
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713:"Aerospaceweb.org | Ask Us - Space Shuttle Challenger Disaster"
1113:'s analysis of pre-disaster non-employment of graphics in Tufte's
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He filed two lawsuits against Thiokol that were later dismissed.
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Roger and Roberta Boisjoly NASA Challenger disaster collection
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549:(some say pressured) Morton Thiokol to reverse its decision.
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1058:"Ethical Decisions - Morton Thiokol and the Space Shuttle
883:"Ethical Decisions - Morton Thiokol and the Space Shuttle
750:"Cas de Challenger : le premier Whistleblower ?"
832:. www.lettersofnote.com. October 27, 2009. Archived from
773:"Lowell native who warned of Challenger blast dies at 73"
227:; April 25, 1938 – January 6, 2012) was an American
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Robison, Wade, Boisjoly, David Hoeker and Stefan Young,
19:"Boisjoly" redirects here. For the Canadian artist, see
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938:"Roger Boisjoly, 73, Dies; Warned of Shuttle Danger"
803:"Roger Boisjoly, 73, Dies; Warned of Shuttle Danger"
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Boisjoly was born on April 25, 1938, in the city of
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AAAS Award for Scientific Freedom and Responsibility
1121:professor; Hoeker and Young freshman RIT students.
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American Association for the Advancement of Science
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American Association for the Advancement of Science
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1153:Deaths from colorectal cancer in the United States
993:"Chapman receives papers from Challenger disaster"
603:Award for Scientific Freedom and Responsibility
310:Simplified cross section of the joints between
277:Boisjoly studied mechanical engineering at the
318:A – steel wall 0.5 inches (12.7 mm) thick
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1029:"'Challenger': The Wrong Story Got Filmed"
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16:American aerodynamics engineer (1938–2012)
1183:University of Massachusetts Lowell alumni
1073:at Chapman University Leatherby Libraries
515:Learn how and when to remove this message
392:Learn how and when to remove this message
1027:Rosenberg, Howard (February 24, 1990).
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1064:Online Ethics Center for Engineering,
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298:(SRBs) for the Space Shuttle program.
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1109:(2002) 8, 59–81) sharply criticizes
936:Martin, Douglas (February 4, 2012).
801:Martin, Douglas (February 3, 2012).
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533:Following the announcement that the
497:adding citations to reliable sources
374:adding citations to reliable sources
830:"The result would be a catastrophe"
248:loss of the spacecraft and its crew
969:. onlineethics.org. Archived from
855:Ware, Doug G. (January 28, 2016).
688:"NLS Other Writings: Say How, A-D"
646:, Boisjoly was portrayed by actor
279:University of Massachusetts Lowell
103:University of Massachusetts Lowell
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1178:Space Shuttle Challenger disaster
1168:People from Lowell, Massachusetts
1119:Rochester Institute of Technology
529:Space Shuttle Challenger disaster
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1066:National Academy of Engineering
1056:Boisjoly, Roger (May 15, 2006)
484:needs additional citations for
361:needs additional citations for
1107:Science and Engineering Ethics
421:shuttle flight in January 1985
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1143:American mechanical engineers
730:collectif, Un (May 7, 2020).
332:D – Strengthening-Cover band,
1173:People from St. George, Utah
1138:American aerospace engineers
1085:Marshall Spaceflight Center
44:Boisjoly testifying at the
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1163:Deaths from cancer in Utah
997:The Orange County Register
861:United Press International
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314:segments; outside at left.
294:, the manufacturer of the
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999:, May 13, 2010 9:37 p.m.
963:"Roger Boisjoly and the
639:made-for-television film
266:Early life and education
112:Attempts to prevent the
1198:People from Nephi, Utah
1158:American whistleblowers
432:tang and clevis joints
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302:O-ring safety concerns
145:Mechanical Engineering
48:panel in February 1986
1101:June 5, 2016, at the
1010:"Leatherby Libraries"
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296:solid rocket boosters
272:Lowell, Massachusetts
72:Lowell, Massachusetts
836:on November 15, 2018
717:www.aerospaceweb.org
493:improve this article
370:improve this article
342:I – fixed propellant
312:solid rocket booster
1148:Engineers from Utah
1115:Visual Explanations
991:Fields, Eugene W.,
692:Library of Congress
229:mechanical engineer
179:Roger Mark Boisjoly
58:Roger Mark Boisjoly
973:on October 6, 2014
942:The New York Times
889:. onlineethics.org
808:The New York Times
779:. February 6, 2012
633:Depiction in media
619:Orange, California
615:Chapman University
344:
340:H – sealing paste,
246:months before the
1123:Alternative link.
1062:Disaster - Index"
1033:Los Angeles Times
881:Boisjoly, Roger.
670:Roger M. Boisjoly
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577:Later career
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486:verification
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151:Institutions
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85:(2012-01-06)
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1193:2012 deaths
1188:1938 births
866:January 28,
840:January 28,
814:February 4,
677:2012-02-07.
648:Peter Boyle
627:Nephi, Utah
322:base O-ring
91:Nephi, Utah
1132:Categories
1094:Challenger
1079:Challenger
1060:Challenger
965:Challenger
947:August 25,
921:August 25,
885:Challenger
777:Lowell Sun
654:References
643:Challenger
559:Challenger
536:Challenger
505:March 2020
463:Challenger
412:Challenger
382:March 2020
243:Challenger
115:Challenger
64:1938-04-25
977:August 5,
967:disaster"
893:August 5,
887:Disaster"
783:March 11,
609:in 1988.
605:from the
562:mission.
235:, and an
1099:Archived
1081:accident
697:July 23,
555:STS-51-L
465:disaster
414:disaster
117:disaster
538:mission
452:(50 °F)
425:O-rings
316:Legend:
252:O-rings
436:fillet
285:Career
141:Fields
129:(1988)
123:Awards
93:, U.S.
74:, U.S.
449:10 °C
221:-zhə-
165:Notes
1040:2020
979:2008
949:2024
923:2024
895:2008
868:2016
842:2012
816:2012
785:2020
699:2017
546:NASA
326:C –
320:B –
80:Died
54:Born
915:NPR
617:in
495:by
372:by
223:LAY
219:BOH
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