Allan J. McDonald

Allan James McDonald (July 9, 1937 – March 6, 2021) was an American engineer, aerospace consultant, author and the director of the Space Shuttle Solid Rocket Motor Project for Morton-Thiokol, a NASA subcontractor. In January 1986, he refused to sign off on a launch of the Space Shuttle Challenger which then broke apart 73 seconds into flight; all seven astronauts on board were killed. Deeply affected by the loss of the Challenger astronauts, McDonald endeavored to reveal the truth about the pressures to stay on launch schedule that led to the tragedy. In 1986, Montana State awarded him an honorary doctorate. following a fall in which he sustained brain damage.

Career McDonald began working for Morton-Thiokol, Inc in 1959 and was first part of the Minuteman missile program; he assisted in designing its external insulation, and was the group leader at Cape Canaveral during its flight tests. Thiokol was contracted by NASA, and McDonald was placed in charge of the space shuttle's solid rocket booster program for two years, with the job often requiring him to travel to the Kennedy Space Center to assess a shuttle's condition prior to flight.

In the lead-up to the Challenger disaster, McDonald and fellow engineers from Thiokol, including Bob Ebeling, Arnold Thompson and Roger Boisjoly, were concerned that frigid overnight temperatures would affect the O-ring seals in the solid rocket booster joints. McDonald refused to sign the official authorization form for a launch, saying, "If anything happens to this launch, I wouldn't want to be the person that has to stand in front of a board of inquiry to explain why we launched."

During the launch of the Challenger McDonald was at Cape Canaveral as the senior representative for his company. The shuttle disintegrated during launch because of failure of the booster rocket joints, killing all seven astronauts. According to McDonald, NASA engineers pressured Thiokol into agreeing to the launch over the concerns expressed by Thiokol engineers, and later tried to cover that up.

Testifying before the Presidential Commission on the Space Shuttle Challenger Accident, also known as the Rogers Commission, McDonald's account revealed the coverup. Neufeld said McDonald "was treated as a traitor and pariah by NASA and his own company, but, thanks in part to congressional pressure, was allowed to redesign the boosters ..." unless McDonald's demotion was reversed.