They said it was an o ring failure, how did they figure it out when everything was blown to bits
In: 54
Fire leaves trails from burning, especially when accelerants (such as fuel) are present. Then, of course, there is a pattern in how things move outward from the source of the failure. Beyond those two patterns, I’d bet rocket scientists have mathematical equations (through physics) and the way debris was scattered as to how high and how far the failure reached that could possibly point to the most likely source. (This part is mere conjecture though)
There are cameras following shuttle launches plus telemetry and sensors all over the vehicle. The gas/flame plume visible lead investigators to an area to focus on. Past launches in cold weather had o-ring issues that nasa management ignored even though the engineers brought up their concerns about the o-rings and past sealing problems in cold weather launches.
They also recovered the booster and it had a big hole where the flames came out on video. And the burned thru strut that failed letting the booster hit the tank.
They weren’t starting from nothing 🙁 O-ring failure was a known concern and conditions were unusually cold and wet (due to melting ice); after the disaster they ran experiments to show what happened to the O-rings under the same conditions.
The disaster was primarily the result of a terrible judgment call in the face of ample concern of a long-standing known problem exacerbated by launch day environmental conditions. It didn’t take much to verify the cause as they already had a good idea.
They had a head start on the investigation because, prior to launch, Allan McDonald, director of Morton Thiokol’s booster-motors program and Roger Boisjoly, their O-ring expert told their bosses and NASA that the cold weather was likely to cause the O-rings to fail and “The result could be a catastrophe of the highest order — the loss of human life.” But the concerns were overruled.
That’s the thing about explosions, they blow things into smaller bits but nothing ceases to be
One of the first things to happen was for ships to be sent out to start recovering debris, specifically focused on finding the parts of the right solid rocket booster where they had seen things get weird
This is something that the NTSB does for any plane crash(often around the world), they gather all the debris and lay it out in it’s original configuration. Once you have that you can start seeing what’s bent/cracked/burned in a way that wasn’t due to the ending crash
In the case of Challenger they managed to recover a lot of the right booster including a part that has been melted through by the hot exhaust plume coming out the side. The whole thing was broken into smaller pieces than it started but a quick explosion and a sustained fire jet do very different things to metal
I wrote a paper about this! Part of how they knew was because the same components had been the subject of a massive cover up/safety concerns case leading up to launch. Basically the engineers in charge of making the o-rings knew that they wouldn’t work below a certain temperature, but weren’t allowed to spend more time and money developing them further, and everyone they brought their concerns to ignored it. There’s actually transcripts of the meetings where the top executives discussed the o-ring problem, realized it wasn’t entirely safe, and decided to launch anyway. There’s of course a lot more layers to this and figuring out who knew what and who passed along which information takes more time that you probably want to spend on this, but the bottom line is that the shuttle exploded because the people who decided stuff didn’t listen to the people who knew stuff. There’s been lawsuits upon lawsuits, and maybe some reparations attempted, but NASA’s not going to like admitting that they blew up a shuttle and five crew members because their executives either ignored important information or never received it because someone else deemed it unimportant. We know that the problem was the o-rings because the engineers made predictions as to exactly how they would fail given the weather they were forced to launch in, and those predictions lined up almost exactly with the actual event. It’s unlikely that anything else was the cause, since all other components were held to a much higher standard. The engineers just hadn’t had time to test and refine them fully before the launch, which had already been delayed once and which NASA wasn’t willing to delay again, even for a safety issue. Hope that helps explain it some.
Feynman’s investigation basically showed that management severely downplayed the risks whereas the engineers generally had a good handle on it. He asked lots of people what they thought the odds of a catastrophic loss of the shuttle due to a failure in their subsystem, and the engineers typically replied 1 in 100, whereas the managers typically replied 1 in 10000.
Over the course of the history of shuttle launches, a kind of complacency and erosion of standards occurred. For examples, the o-rings were expected to ***not to burn through at all***, whereas on earlier flights they had seen up to a third of the thickness of the rubber burned through, typically when launched on colder days. This got written as “a safety factor of three”.
Feynman’s report is an appendix to the Rogers Commission report, and is 100% worth a read. https://history.nasa.gov/rogersrep/v2appf.htm
The report and a few (good) documentary films are available, but the short-version is that it is visible in the launch film once you know to look for it.
TW: images of the craft exploding
The infographic over at [space.com](https://space.com) covers the basics pretty well. direct link to infographic: [https://cdn.mos.cms.futurecdn.net/LqUztPnzVZLExP66bZLdQL-970-80.jpg.webp](https://cdn.mos.cms.futurecdn.net/LqUztPnzVZLExP66bZLdQL-970-80.jpg.webp)
Longer article with more info/images that the infographic comes from: [https://www.space.com/31732-space-shuttle-challenger-disaster-explained-infographic.html](https://www.space.com/31732-space-shuttle-challenger-disaster-explained-infographic.html)
edit: even if anyone had noticed the little fire in real time AND been able to yell to abort, it likely would not have helped. The three motors on the actual craft (by the tail) can turn on and off just like a car or an airplane, but the tall white booster motors are like a big Roman Candle — once lit, they go until they burn out on their own, their is no turning them off once they light. And the craft had no option to abort until the boosters separated, at which time the shuttle had the option to either return to the Cape, abort to an international runway (varied depending on the intended orbital inclination), abort once-around (basically nearly going to orbit but doing like an ICBM instead and landing back in the states after a partial highly-decayed orbit), or abort to orbit (which would require repair or rescue to return to earth). There was no abort before the booster separation, though.
Additionally, corporate nepotism meant the contract to manufacture the enormous fuel tanks were very inconveniently (and stupidly) made on the other side of the country. Because of their size they needed to be made in two halves to facilitate transport across the country to Florida. The two halves meant they needed the infamous rubber ‘O’ rings that failed in the cold launch conditions and were warned about by junior engineers on launch day. So why did it blow up .. greedy bastards caused it .. as usual.
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