Allan J. McDonald

1937 - Present

Chemical Engineer

Personal Life

Allan J. McDonald was born in Cody, Wyoming and is the youngest of four children. He eventually moved to Bozeman, Montana where he spent most of his childhood. He attended Montana State University (MSU) then moved to Utah after college to peruse his career in rocketry. He currently lives in Ogden Utah, the father of four grown children and seven grandchildren.

Resume/ Education

Allan McDonald attended Montana State University (MSU) and received his associate degree in pre-engineering in 1957 and Bachelors of Science degree in Chemical Engineering in 1959. He then got a job from Morton Thiokol as an engineer for the stage 1 Minutemen ballistic missiles. In 1967 he went back to school to the University of Utah and received his Masters in Engineering Administration. He continued to work at Morton Thiokol as on of the chief engineers on the Solid Rocket Boosters (SRB) for the Space Shuttle. He was the project manager of the O-Rings on the solid rocket motors (SRM). later in 1986 he received the award of Honorary Doctor of Engineering from Montana State University.

The Challenger Accident

Allan McDonald was involved in one of the worst events in space exploration history. The Challenger went up on January 28, 1986 at 11:38 EST. 73 seconds later it exploded into multiple parts and all seven crew members, one being a school teacher, died. The explosion was due to a leak in the O-rings that McDonald's team worked on. The Challenger launch was postponed several times due to questionable weather in the area. On the night before the launch the meteorologists saw a gap in the forecast where they would be able to launch the shuttle safely. Before any shuttle takes off all the members of the flight deck and flight control must sign off that their part of the shuttle will and is ready for launch, this is usually done the night before the launch and all the members who will need to sign off have most likely checked over and over that their part is working perfectly and they have had time to make the decision to sign off or not. On the night of the launch NASA was rushed and not all the members had a good chance to review their partof the shuttle. All the members signed off for the launch except for McDonald, he argued that the O-rings had never been tested in the weather conditions that were forecasted for the next day, which were 31°F. McDonald said that if the O-rings became too cold prior to launch, they would freeze and then crack open from the immense heat at takeoff thus creating a crack in the booster rocket. Unfortunately McDonald's boss over ruled him and they proceeded to launch. The next day the launch pad was covered in ice and crews did everything they could to get the ice off shuttle and the pad, but still the launched the shuttle. 73 seconds after launch the shuttle exploded which was later concluded to be caused by a break in the O-ring at liftoff.
nasa472.jpg(Actual O-Ringon the booster Rocket Endeavor)
After the event McDonald was fired from his job and was used as a large informant in the investigation of the Challenger Accident NASA and the federal government on what exactly went wrong the day of the accident. A few years after the events of the Challenger had boiled down McDonald was told by congress that he would be put in charge of the new O-ring project. McDonald created a new mechanism to the O-rigns that is technically fail proof. He uses a dual clevis mechanism that hitches on to the other clamp essentially producing a double clamp that is twice as strong and can withstand far lower temperatures that the last O-ring design could. By creating a new design for the O-ring McDonald and his team successfully got the space program back on its feet and back into space.

Present Day

McDonald retired from Morton Thiokol in 2001, but he still works with them on upcoming prject designs or help. McDonald has recently written a book called "Truth Lies and O-Rings" and it talks about the events leading up to, during and after the challenger accident and it give his point of view on the events and it shows how much his life changed due to this accident. McDonald is currently traveling around the nation giving lectures and talks to differnet Colleges and conventions about topics such as his book, safety, leadership and ethics. He currently lives in Utah and skis around 30 to 40 days a year.


1937 - Born in Cody, Wyoming

1957 - Associate Degree in pre-engineering MSU

1959 - Bachelors of Science Degree in Chemical Engineering

1959 - Joined Morton Thiokol

1959 - Began work on the Stage 1 Minutemen Missile: Specifically the external insulation design for the first underground silo hot-launched ballistic Missile

1967- Masters Degree - Engineering Administration

1968 - Successful demonstration of a large dual chamber controllable solid (DCCS)

1976 - Automobile airbag propellant R&D

1979 - Automobile air bag system R&D

1984 - Chairman, Senior Materials Review Board for the Solid Rocket Motor (SRM)

1986 - Attempted to prevent Challenger launch on 28 Jan. 1986

1986 - 1987 - Responsible for establishing new specification requirements, redesign approach, defining test program and recertification activities for redesigned SRM (RSRM)

1987 - 1989 - Vice President of Engineering, Space Operations

1987 - 1989 - Management responsibility for detailed design, test, analysis, flight certification, and flight readiness of the first three instrumented Shuttle flights with the RSRM

1989 - 2001 - VP, Advanced Technology and Technical Director

2001 - present - Traveling the country as a keynote speaker and also skis all winter long


Allan J. McDonald has prove to be one of the most important (behind the scenes) Engineers for NASA because after the challenger accident NASA was very cautious about trying to launch another shuttle because they were in fear that the same thing would happen to the next shuttle as well. When McDonald created the newer and safer design for the O-ring it gave NASA a reason to go back into space and to keep up with the technologies of other countries at the time. We chose McDonald because we were very interested in the Challenger accident and by learning about McDonald we can also learn about what really when on the Night of January 27, 1986. Also McDonald is my grandfather and it only was norma for me to wirte about him becase he is such a large inspiration in my life and because of him i live my life try to reach the goals that he put forth for him to conquer and he did exaclt y that and if i could do something in my life that makes as large as an impact that my grandfather made i would be ecstatic.


a. We chose this scientist because we are very interested in the space program and by researching McDonald we can learn about NASA and one of the largest accidents in space history. Also McDonald is my grandfather and he is probly the largest role model in my life and i love to write about him and research him because he makes a huge impact in my life.

b. Allan McDonald's O-ring design on the challenger space shuttle failed and resulted in the shuttle exploding and all the crew members died. Allan argued against the launch the night before explaining that his O-rings were never tested in temperatures as cold as the day of the launch. After the Challenger accident McDonald was faced with a new challenge, he needed to design a new O-ring technology that would be safer and withstand far colder temperatures. Mcdonald also had to create a design that would have to be flawless or NASA would not send the shuttle into space.

c. The new design had a dual clevis type of connection so there was a "backbone" in the O-ring so the pressure of the heat and the gravity force would be evenly distributed throughout the o-rings making them stronger. The new design had to be much stronger because if there as any doubt at all NASA would not let the shuttle go up because the last thing they wanted was another Challenger accident to occur.

d. The Engineering involved had to do a lot with the melting and freezing point of the rubber and the metal because they engineers from Thiokol had to mae sure that this new o-rig would withstand far greater and lesser temperatures. They also had to engineer the design because the o-ring does have to hold together massive rockets while they are exerting some of the most powerful forces know to man.

e. The more recent studies in the field of the booster rocket is that some space industries are trying to build a larger rocket that will take astronauts farther and much faster. A new booster rocket series is possibly in the works that will have booster rocket s of 25 to 50% large than the ones today and the O-rings used in those rockets will resemble the same type of O-ring that McDonald embeddded into the present day booster rockets.

f. The new O-rig technology brought NASA back up onto its feet after the Challenger and because of the new O-ring technology we have been able to send many missions and shuttles up into space and we were able to create the international space station. Also there has not been a problem with the O-rings since they were redesigned in 1987.

g. By watching my grandfather do so much and has made a huge impact on the Nation really makes me proud of him and all i could ask for it to walk in his footsteps because he accomplished something most people dream of doing, getting NASA back on their feet. In our time now we need someone like my grandfather who will do something for NASA that will keep the US in the space race and further more help the world explore more of the universe.

Good Links for Videos and quotes related to McDonald



Allan J. McDonald. 2008. Photograph. Feb. 2008. Web. 25 Sept. 2011.

Becker, Michael. "MSU News Service - Engineer Who Warned of Trouble before Challenger Disaster to Sign Books Today." Montana State University. Web. 25 Sept. 2011. <>

Challenger. 1986. Photograph. Google Images. Web. 25 Sept. 2011.

Challenger Disaster Live on CNN. YouTube - Broadcast Yourself. 24 July 2007. Web. 25 Sept. 2011. <>.

May. "Space Shuttle Challenger Disaster." Wikipedia, the Free Encyclopedia. Web. 26 Sept. 2011. <>

"NASA - STS-51L." NASA - Home. Ed. Jeanne Ryba. Web. 25 Sept. 2011. <>.

NASA. 2004. Photograph. Cape Canaveral. USA Today. 2004. Web. 25 Sept. 2011. < endeavour_N.htm>.

"Resume." Allan J McDonald. 2010. Web. 25 Sept. 2011. <>

Shuttle Launch Photo. Photograph. Cape Canaveral. White Gadget. Web. 25 Sept. 2011. <>.


Zach Patinkin
Robbie Fischer