January 28, 1986

[KevinTodd]

Originally Posted by Nostril Cheese

Remember those booms vividly. My dad took us out to Edwards once to watch the Shuttle land. Very cool.

Totally. We called them east coast quakes.

I gotta look you up next time I'm in Portland.

[sammyg2]

I asked pops what he knew about the challenger boom-boom, this is what he replied:

The ambient temperature was near 40 deg causing the massive amount of steel and the rubber 0-rings to thermally shrink causing the o-ring compression to be below that required to hold the motor pressure. It was rumored that political influence was brought to bare to go on with the firing even through the Thiokol engineers vehemently opposed it. The coefficient of thermal expansion of steel is about 6 X 10 to the minus 6 inches/inch/deg F and that of the rubber O-ring material (probably neoprene or Buta-diene) is about 12 X 10 to the minus 5 inches/inch/deg F. Normal design temperature is usually about 75 deg F and the temp at firing was 35 deg below that. The resultant thermally caused reduction in O-ring compression was probably close to 75% of designed.


My company made the ablative insulating rings that covered the flanges of the solid booster segments.
The solid booster was made in sections, approximately 12' long by 18' in diameter. Solid propellant was cast and cured inside the steel cylinders and then machined to the final ballistic configuration.
These segments were shipped by rail from Thiokol in Utah to the Cape where they were stacked with o-rings between the flanges.
After assembly of the motor segments, the "Kick Rings" were used to cover the flanges.
The kick rings were ablative insulators designed to prevent the extreme heat from burning through the steel motor cases.
The "kick rings" were fabricated by laying up silica-phenolic fabric patterns and then curing in an autoclave.
The cured rings were then machined to the final configuration.
Each ring was made up of several segments that were assembled into the final ring when installed on the booster motor.

[quicksix]

I was at the barracks at NAS Lemoore, we were watching on the tv.
Absolutely stunned...

[74-911]

I also remember it well, watching it on live TV. Forever burned into the collective memories along with JFK, MLK, 9/11, etc.

But how many remember this aspect of the disaster:

Remembering Roger Boisjoly: He Tried To Stop Shuttle Challenger Launch : The Two-Way : NPR

[Nostril Cheese]

Originally Posted by KevinTodd

Totally. We called them east coast quakes.

I gotta look you up next time I'm in Portland.

Right on. We can either blast shotguns or blast Marshalls.

[WPOZZZ]

I was in my Soc 495 class (we gave tests to Soc 100 students in unit mastery) when my partner came in and told me the shuttle exploded. He came in with a cooler all the time because he played softball prior to class, and said fcuk it and took out a couple beers. Depressing as fcuk. After our shift finished, he went to his job to protect the public (leo).

[Ronbo]

I was a Department of Defense auditor working at the Lockheed Skunk Works in Burbank. We were gathered together by the branch manager who told us what happened. So sad.


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[Hawkeye's-911T]

Paraphrasing Glen - definitely one of those flashbulb memory moments in my lifetime - the assassination of JFK - the Challenger accident - the WTC bombings of Sept. 11. Stuff like that seems to always stay with you & invariably seems to be the bad $ch1t.

May they all rest in peace
JB

[flipper35]

I was in my HS Calculus class when the office lady walked in, whispered in my teachers ear and he had a shocked look and they walked out. A few minutes later they came on the intercom to let us know what happened. My calc teacher was one of the ten teacher finalists and they wanted to tell him first. Went home and watched the news which was stupid because it was all speculation.

[Mark Henry]

The day I asked my wife out on our first date.
Hard to forget that one.

[sammyg2]

I saw the challenger explosion on TV. I was at home, recovering from a back operation.

when I heard about the Columbia accident I was at a PCA breakfast meeting at Hoff's hut.

[Baz]

The Columbia exploded 13 years ago today......

[sammyg2]

spooky.

[nzporsche944s2]

Is it true or false that the crew would have survived the initial explosion but been killed by the impact with the ocean 2 minutes later?

Snopes says "False" but this report from NBC says its true. Anyone have any links to facts?

Chapter 5: An eternity of descent - Technology & science - Space - Space History | NBC News