Roger Boisjoly

Roger Boisjoly (born 25 April 1938) is an engineer who worked for Morton Thiokol, the manufacturer of the solid rocket boosters of the Space Shuttle Challenger.

O-Ring Safety Concerns

He wrote a memo in July of 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 the Space Shuttle. Such a catastrophic event did occur during the Space Shuttle Challenger disaster.

This memo followed his investigation of a Solid Rocket Booster from a shuttle flight in January 1985. During his investigation, he discovered that the first of a system of 2 "O-Rings" had failed completely, and that some damage had been caused to the second "O-Ring".

The "O-Rings" were two rubber rings that formed a seal between two sections of the Solid Rocket Boosters. The rings never functioned according to design. They were supposed to sit in a groove and seal the joint between the sections of the booster. It was found, however, that the pressure of the burning rocket fuel caused the joints in the SRB's to flex during launch, 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 gasses could escape, a process called blow-by. These hot gasses would cause damage to the rings until the seal was achieved.

What Boisjoly's investigation showed was 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. Colder temperature made the rubber hard and less flexible, meaning that extrusion took more time and more blow-by took place. He determined that if the O-rings were damaged enough they could fail.

If the second O-Ring had failed, Boisjoly realized, the results would almost certainly have been catastrophic with the complete loss of the shuttle and crew seemingly the only outcome. His investigation found that the first O-ring failed because of 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 10 °C - the coldest on record (until 28 January 1986). The first rubber O-ring had formed a partial seal, but not a complete one, but fortunately the second O-ring had held.

Boisjoly sent a memo, describing the problem to his managers, but was apparently ignored. It is true that Morton Thiokol were in discussions with NASA with regards to a new contract (reportedly worth up to $1 Billion) and it is possible that the management were concerned that any issues discovered with the Solid Rocket Boosters may compromise the chances of the contract being renewed. Fact|date=July 2007

Following several further memos, a "taskforce" was set up - including Boisjoly - to investigate the matter, but after a month Boisjoly realized that the taskforce had no power, no resources and no management support.

Eventually, in late 1985 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.

Challenger Disaster

Following the announcement that the Challenger mission was confirmed for 28 January 1986, Boisjoly and his colleagues tried to stop the flight. Temperatures were due to be down to −14 °C overnight. Boisjoly felt that this would severely compromise the safety of the O-Ring - and potentially lose the flight.

The matter was discussed with Morton Thiokol management - who agreed that the issue was serious enough to recommend delaying the flight. They arranged a telephone conference with NASA management and gave their findings. However, after a while, the Morton Thiokol managers asked for a few minutes off the phone to discuss their final position again. Despite the efforts of Boisjoly and others in this off-air briefing, the Morton Thiokol managers decided to advise NASA that their data was inconclusive. NASA asked if there were objections. Hearing none, the decision to fly the ill-fated STS-51L Challenger mission was made.

Boisjoly's concerns proved correct. In the first moments after ignition the O-rings failed completely and were burned away, resulting in the black puff of smoke visible on films of the launch. This left only a layer of aluminum oxide (a combustion product) to seal the joint. At 59 seconds after launch, buffeted by high-altitude winds, the oxide gave way. Hot gases streamed out of the joint in a visible torch-like plume that burned into the external hydrogen tank. At about 73 seconds, the adjacent SRB strut gave way and the vehicle quickly disintegrated.

Boisjoly was quite relieved when the flight lifted off, as his investigations had predicted that the SRB would explode during the initial take-off. Seventy-three seconds later he witnessed the shuttle disaster on TV.

Career Post-Challenger

After Ronald Reagan ordered a Presidential Committee 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. After the Committee gave its findings, Boisjoly found himself shunned by colleagues and managers and he resigned from the company.

Boisjoly became a speaker on workplace ethics. [cite web | title = Roger Boisjoly and the "Challenger" disaster | publisher = onlineethics.org | url = http://www.onlineethics.org/cms/7123.aspx | accessdate = 2008-08-05 ] He argues that the caucus called by Morton Thiokol managers, which resulted in a recommendation to launch, "constituted the unethical decision-making forum resulting from intense customer intimidation." [cite web | last = Boisjoly | first = Roger | authorlink = Roger Boisjoly| title = Ethical Decisions - Morton Thiokol and the Space Shuttle "Challenger" Disaster: Telecon Meeting| publisher = onlineethics.org | url = http://www.onlineethics.org/CMS/profpractice/ppessays/thiokolshuttle.aspx| accessdate = 2008-08-05 ]

Source of information

External links

*The [http://www.onlineethics.org/CMS/profpractice/ppessays/thiokolshuttle.aspx] written by Boisjoly is posted online as a case-study from the CWRU Online Ethics center.
*NASA Marshall Spaceflight Center has a [http://history.msfc.nasa.gov/book/chptnine.pdf history of the Challenger accident] discussing the O Ring and Boisjoly's objections to flight