The crucial O-rings on the Challenger space shuttle required a split-second functioning to seal during the launch. “If the primary ring did not seal within the first six hundred milliseconds after ignition, then it was highly likely that the secondary seal would be destroyed before it had a chance to close the gap between the two halves of the joint.” And then, the gas could escape, ignite the half-million gallons of propellant on the rocket, and result in “loss of vehicle, mission, and crew.”
The engineers at Morton Thiokol who designed the rings knew that if the Challenger launched during the record cold in Florida (29 degrees), the O-rings would be too stiff to function properly in those initial milliseconds. They recommended a “no go” during a special conference call the night before Challenger was scheduled to lift off, stating that launch needed to be at 53 degrees or warmer.
But on that call was another engineer from NASA who pointed out that the O-rings had held in previous flights, that there was redundancy with two rings in place, and that it was the night before the launch — a very inconvenient time to raise this issue (a shuttle had never been scheduled to launch in freezing weather before). Morton Thiokol took a “five-minute caucus” to discuss.
During that time, the managers on the call came face-to-face with the fact that the company was days away from a summit about the renewal of their monopoly on a billion-dollar rocket contract, they were behind schedule in production for other rockets, and NASA had all eyes on it for the Teacher-in-Space flight. They were asking to cancel hours before the flight on a theoretical engineering hypothesis — with so much to lose either way. They “made a management decision” and reconsidered.
It’s easy to think that if we were in their shoes, we would have taken the high ground and stuck with the “no go” recommendation. But when billions of dollars and the fate of the company — “perhaps even the fate of the space program itself” were at stake, it’s easier to capitulate than to stand firm.
Fortunately, not everyone takes the easy road as we’ll see tomorrow…
Source: Challenger by Adam Higginbotham, 2024
