Challenger: A True Story of Heroism and Disaster on the Edge of Space

New to his position as Director of the Space Shuttle Solid Rocket Project, Thiokol’s Allan McDonald faced the increasing stress of the Flight Readiness Review. His would be the tiebreaking vote as to whether or not to launch, causing him extreme anxiety.

Meanwhile, the boosters were recovered from Ron McNair’s 1984 flight. Technicians were alarmed to discover erosion in the O-rings, suggesting that the findings back in 1981 were not an isolated incident. Nevertheless, since the O-rings had ultimately functioned correctly, they reported that the erosion was “not a constraint to future launches” (206). 

When the rockets were recovered from Judy Resnik’s flight, a new problem was discovered: Soot appeared between the first O-ring and its backup. This meant that the heat had scorched a hole in the putty that sealed the first O-ring—thus, the O-ring problem was worsening with each launch. Since the backup O-ring had operated as it was designed to, the engineers once again deemed the rockets within the parameters of acceptable risk. However, by allowing for these compromises in the O-ring performance, NASA was widening its criteria for acceptable risk.

In September 1984, the two Hughes employees—along with two alternates—traveled to Florida to begin training.