The soccer ball that survived the Challenger explosion • Hacker News Board

Re: The soccer ball that survived the Challenger explosion

#21

Post by jcranendonk » Mon, Jul 02, 2018, 9:02 PM UTC

colechristensen wrote: post #19

runciblespoon wrote: post #7

"the solid rocket boosters ignited and somewhere in the right booster, a 0.280-inch-wide O-ring failed due to the cold." The 'solid rocket boosters' being constructed in segments because they had to be transported by rail from Utah. They had to be constructed in that state as part of the deal to get the politicians to vote in the finances.

You seem to be implying that a root cause of the accident was the political spreading around of construction. Rockets are incredibly complex machines, you could use this sort of post hoc reasoning to find cause and blame for any anomaly by saying such a part could have been done differently. You couldn't ever use this reasoning to make design decisions that prevented accidents.

What it really comes down to is that the Challenger exploded due to man's folly in exploring outer space. /s

Re: The soccer ball that survived the Challenger explosion

#22

Post by cortesoft » Mon, Jul 02, 2018, 9:03 PM UTC

runciblespoon wrote: post #7

"the solid rocket boosters ignited and somewhere in the right booster, a 0.280-inch-wide O-ring failed due to the cold." The 'solid rocket boosters' being constructed in segments because they had to be transported by rail from Utah. They had to be constructed in that state as part of the deal to get the politicians to vote in the finances.

I mean, was the alternative to construct them on site? Is that what would have happened if not for the political pressure? It seems likely that they would have been manufactured SOMEWHERE requiring transport, no matter what.

Re: The soccer ball that survived the Challenger explosion

#23

Post by rmason » Mon, Jul 02, 2018, 9:34 PM UTC

I was visiting farmers reviewing plans for the next crop year. I'd just arrived and the farmer says do you mind if we watch the Challenger launch before starting? It's got that teacher going up in space. I told him that my high school government teacher had been one of the ten finalists so I took a pretty keen interest myself.

I can remember the numbness I felt in his living room as we watched the Challenger explode. It's something once viewed that you can't unsee. Words fail you in trying to explain it.

I had no idea at the time that there were five engineers who tried valiantly to stop the launch because of the cold weather and failed.

https://www.npr.org/sections/thetwo-way/2016/01/28/464744781...

Re: The soccer ball that survived the Challenger explosion

#24

Post by jedberg » Mon, Jul 02, 2018, 9:40 PM UTC

robryk wrote: post #16

jedberg wrote: post #10

Earlier quoted context omitted.

I see what you're getting at, but the separate construction and transport was not the issue here. The O ring was a necessary pressure valve, but it failed because the cold made it brittle. The bigger issue here was the politics between Nasa and it's contractors. The contractors told them that the launch would be dangerous at the temperature, but they were ignored.

> The O ring was a necessary pressure valve (...) Do I understand correctly that you're saying that the O-ring would be necessary even if the SRBs were constructed as a single long tube, instead of segments that are assembled together? If so, would you mind expanding on that? I was under the impression that the only reason the whole O-ring and caulking of the joints was necessary was the existence of the joints.

I'm not a rocket scientist so I might be wrong, but I'm pretty sure the O ring would be required no matter how it was constructed.

Re: The soccer ball that survived the Challenger explosion

#25

Post by erik_seaberg » Mon, Jul 02, 2018, 9:49 PM UTC

cortesoft wrote: post #22

runciblespoon wrote: post #7

"the solid rocket boosters ignited and somewhere in the right booster, a 0.280-inch-wide O-ring failed due to the cold." The 'solid rocket boosters' being constructed in segments because they had to be transported by rail from Utah. They had to be constructed in that state as part of the deal to get the politicians to vote in the finances.

I mean, was the alternative to construct them on site? Is that what would have happened if not for the political pressure? It seems likely that they would have been manufactured SOMEWHERE requiring transport, no matter what.

Could have used a ship; that's how they delivered the larger Saturn V stages from New Orleans and Seal Beach to Cape Kennedy.

Re: The soccer ball that survived the Challenger explosion

#26

Post by mehrdadn » Mon, Jul 02, 2018, 9:53 PM UTC

rmason wrote: post #23

I was visiting farmers reviewing plans for the next crop year. I'd just arrived and the farmer says do you mind if we watch the Challenger launch before starting? It's got that teacher going up in space. I told him that my high school government teacher had been one of the ten finalists so I took a pretty keen interest myself. I can remember the numbness I felt in his living room as we watched the Challenger explode.…

> The night before the launch, Ebeling and four other engineers had tried to stop the launch. Their managers and NASA overruled them. That night, he told his wife, "It's going to blow up."

This sent chills down my spine... the world just shouldn't be like this.

Re: The soccer ball that survived the Challenger explosion

#27

Post by Symmetry » Mon, Jul 02, 2018, 10:02 PM UTC

cortesoft wrote: post #22

runciblespoon wrote: post #7

"the solid rocket boosters ignited and somewhere in the right booster, a 0.280-inch-wide O-ring failed due to the cold." The 'solid rocket boosters' being constructed in segments because they had to be transported by rail from Utah. They had to be constructed in that state as part of the deal to get the politicians to vote in the finances.

I mean, was the alternative to construct them on site? Is that what would have happened if not for the political pressure? It seems likely that they would have been manufactured SOMEWHERE requiring transport, no matter what.

For example, SpaceX builds all their rockets in LA and transports them by truck to the launch site. With their next, bigger, rocket they'll send them by ship.

Blue Origin is planning to build their big rockets in Florida near the launch site.

Re: The soccer ball that survived the Challenger explosion

#28

Post by 0xffff2 » Mon, Jul 02, 2018, 10:09 PM UTC

jedberg wrote: post #24

robryk wrote: post #16

Earlier quoted context omitted.

> The O ring was a necessary pressure valve (...) Do I understand correctly that you're saying that the O-ring would be necessary even if the SRBs were constructed as a single long tube, instead of segments that are assembled together? If so, would you mind expanding on that? I was under the impression that the only reason the whole O-ring and caulking of the joints was necessary was the existence of the joints.

I'm not a rocket scientist so I might be wrong, but I'm pretty sure the O ring would be required no matter how it was constructed.

Why do you think that? As the person you replied to said, the only reason the O-ring is there at all is to seal the joint between the sections. If the join't didn't exist, there would be no reason at all for there to be a rubber ring embedded in the structure.

Re: The soccer ball that survived the Challenger explosion

#29

Post by [deleted] » Mon, Jul 02, 2018, 10:11 PM UTC

jedberg wrote: post #10

runciblespoon wrote: post #7

"the solid rocket boosters ignited and somewhere in the right booster, a 0.280-inch-wide O-ring failed due to the cold." The 'solid rocket boosters' being constructed in segments because they had to be transported by rail from Utah. They had to be constructed in that state as part of the deal to get the politicians to vote in the finances.

I see what you're getting at, but the separate construction and transport was not the issue here. The O ring was a necessary pressure valve, but it failed because the cold made it brittle. The bigger issue here was the politics between Nasa and it's contractors. The contractors told them that the launch would be dangerous at the temperature, but they were ignored.

[deleted]

Re: The soccer ball that survived the Challenger explosion

#30

Post by 0xffff2 » Mon, Jul 02, 2018, 10:11 PM UTC

erik_seaberg wrote: post #25

cortesoft wrote: post #22

Earlier quoted context omitted.

I mean, was the alternative to construct them on site? Is that what would have happened if not for the political pressure? It seems likely that they would have been manufactured SOMEWHERE requiring transport, no matter what.

Could have used a ship; that's how they delivered the larger Saturn V stages from New Orleans and Seal Beach to Cape Kennedy.

To clarify, there are many places where the boosters could have been manufactured and transported by ship. The shuttle SRB's where manufactured in Utah, where transportation by ship is impractical.