Posted on 01/28/2019 1:31:02 PM PST by SMGFan
yep - there was evidence of burn-through several times before
We went over to the NASA side of the building and watched the unedited footage being fed to us from KSC.
He watched the event once with no external input or narration and said that it was the seals, right off.
One early theory was that there was a “water hammer effect” in the 18” LOX duct that carried oxidizer from the nose of the the external tank to the engines.
I recorded all the TV coverage I could find on my (brand new) VHS VCR, and frame-stepped through the explosion footage. There was one particular frame in which the LOX tank ruptured and exploded, it looked like a gigantic blue-white electric arc.
Before the truth came out, the “water hammer effect” was about the only explanation going. IIRC, it took maybe a week before the “SRB field joint” explanation began to be heard.
The first two of the three O-ring seals were failing regularly.
...
No they weren’t, but the engineers knew they couldn’t take the cold.
NASA management also knew the Apollo 1 fire was likely. They also knew that a foam strike could be deadly and that Columbia was struck. They didn’t care. While Columbia was in orbit, another Shuttle was on the pad that could have been launched to rescue the Columbia crew.
...........and even then the lying Fake News Media tried to blame President Reagan for what happened.
The offending compound was asbestos, I believe.
The accident was 1986, not 1985. I had to look it up. I had just started my working career around that day.
I was at a board meeting when the chairman’s secretary ran into the room crying that the shuttle had exploded. It was horrible. Everyone in that room was speechless.
I don’t recall anybody getting prosecuted. Were there any?...................
Overall his record as POTUS was stellar, but Reagan did blow a few calls along the way.
The idea of sending a teacher into space was one of them.
Promising to nominate a woman to SCOTUS, taking a Democrat deal on border security, caving to MADD to use Federal highway money to blackmail states, and pulling the Marines out of Lebanon (which encouraged the OBL types to do more terrorism) all come to mind.
My recollection is that it came out over the next few months that there had been incidents of burn through of one or more O-rings, but that it hadn’t made it through all three.
The eruption of exhaust gas through all three O-rings caused an immediate and measurable decrease in SRB internal pressure. This was seen in the Challenger telemetry data. It also caused a visible plume to be emitted from the SRB body; if that had happened before the Challenger explosion, I’m sure it would have been made public by now. Space shuttle launches were well covered by long range cameras all the way to the point of SRB separation.
There were signs of erosion and one complete burn through an inner o-ring, but not a burn through the second. The cold temperatures on the morning of the Challenger disaster made the difference.
From Wiki:
O-ring concerns
Challenger being carried atop a Crawler-transporter on the way to the launch pad
Each of the Space Shuttle’s two Solid Rocket Boosters (SRBs) was constructed of seven sections, six of which were permanently joined in pairs at the factory. For each flight, the four resulting segments were then assembled in the Vehicle Assembly Building at Kennedy Space Center (KSC), with three field joints. The factory joints were sealed with asbestos-silica insulation applied over the joint, while each field joint was sealed with two rubber O-rings. (After the destruction of Challenger, the number of O-rings per field joint was increased to three.)[6] The seals of all of the SRB joints were required to contain the hot, high-pressure gases produced by the burning solid propellant inside, thus forcing them out of the nozzle at the aft end of each rocket.
During the Space Shuttle design process, a McDonnell Douglas report in September 1971 discussed the safety record of solid rockets. While a safe abort was possible after most types of failures, one was especially dangerous: a burnthrough by hot gases of the rocket’s casing. The report stated that “if burnthrough occurs adjacent to [liquid hydrogen/oxygen] tank or orbiter, timely sensing may not be feasible and abort not possible”, accurately foreshadowing the Challenger accident.[7] Morton-Thiokol was the contractor responsible for the construction and maintenance of the shuttle’s SRBs. As originally designed by Thiokol, the O-ring joints in the SRBs were supposed to close more tightly due to forces generated at ignition, but a 1977 test showed that when pressurized water was used to simulate the effects of booster combustion, the metal parts bent away from each other, opening a gap through which gases could leak. This phenomenon, known as “joint rotation,” caused a momentary drop in air pressure. This made it possible for combustion gases to erode the O-rings. In the event of widespread erosion, a flame path could develop, causing the joint to burst—which would have destroyed the booster and the shuttle.[8]
Engineers at the Marshall Space Flight Center wrote to the manager of the Solid Rocket Booster project, George Hardy, on several occasions suggesting that Thiokol’s field joint design was unacceptable. For example, one engineer suggested that joint rotation would render the secondary O-ring useless, but Hardy did not forward these memos to Thiokol, and the field joints were accepted for flight in 1980.[9]
Evidence of serious O-ring erosion was present as early as the second space shuttle mission, STS-2, which was flown by Columbia. Contrary to NASA regulations, the Marshall Center did not report this problem to senior management at NASA, but opted to keep the problem within their reporting channels with Thiokol. Even after the O-rings were redesignated as “Criticality 1”—meaning that their failure would result in the destruction of the Orbiter—no one at Marshall suggested that the shuttles be grounded until the flaw could be fixed.[9]
After the 1984 launch of STS-41-D, flown by Discovery, the first occurrence of hot gas “blow-by” was discovered beyond the primary O-ring. In the post-flight analysis, Thiokol engineers found that the amount of blow-by was relatively small and had not impinged upon the secondary O-ring, and concluded that for future flights, the damage was an acceptable risk. However, after the Challenger disaster, Thiokol engineer Brian Russell identified this event as the first “big red flag” regarding O-ring safety.[10]
By 1985, with seven of nine shuttle launches that year using boosters displaying O-ring erosion and/or hot gas blow-by,[11] Marshall and Thiokol realized that they had a potentially catastrophic problem on their hands. Perhaps most concerning was the launch of STS-51-B in April 1985, flown by Challenger, in which the worst O-ring damage to date was discovered in post-flight analysis. The primary O-ring of the left nozzle had been eroded so extensively that it had failed to seal, and for the first time hot gases had eroded the secondary O-ring.[12] They began the process of redesigning the joint with three inches (76 mm) of additional steel around the tang. This tang would grip the inner face of the joint and prevent it from rotating. They did not call for a halt to shuttle flights until the joints could be redesigned, but rather treated the problem as an acceptable flight risk. For example, Lawrence Mulloy, Marshall’s manager for the SRB project since 1982, issued and waived launch constraints for six consecutive flights. Thiokol even went as far as to persuade NASA to declare the O-ring problem “closed”.[9] Donald Kutyna, a member of the Rogers Commission, later likened this situation to an airline permitting one of its planes to continue to fly despite evidence that one of its wings was about to fall off.
So which is it? Did he say this on Jan 28, 1985 or today? Find it hard to believe he said it today since he’s dead.
Please see my post #32.
I don't think so, but I do think Roger Boisjoly suffered some career damage because he went outside the chain of command to report his concerns.
Thanks Moonman.
President Ronald Reagan
She was from NH.
It was right after the Pats were squashed in the Super Bowl by Chicago. The joke are New England was, “What did the Challenger have in common with the Pats.? The both looked good for 72 seconds.”
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