Allan James McDonald (July 9, 1937 – March 6, 2021) was an American engineer, aerospace consultant, author[1] 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;[2] all seven astronauts on board were killed.

[3] 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.

[3] 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.

[9] 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.

[3] Deeply traumatized by the deaths of the Challenger crew, McDonald fought to hold those responsible accountable and explain the reasons for the failure, saying that pressure to meet launch schedules led to the loss.

[12] According to Michael J. Neufeld,McDonald went on to demolish the post-accident cover-up, and risk his livelihood and career, when he interrupted the testimony of NASA officials before the Rogers Commission to give his account of what happened.

[5] McDonald donated his personal papers on the accident to Chapman University in 2016[1] and expressed hope that they would assist in preventing the same mistakes from being made.