Challenger 30 Years on

Hard to think it was 30 years ago that the Space Shuttle Challanger exploded shortly after lift off. Sure I was in High School at the time but even on this side of the pond I was aware of the mission and the teacher n space. How many others remember where they were that day.

Sure looking back with hindsight we can say they should never have launched in temps that cold but as with many accidents we learn and strive to ensure they never happen again.

 

I was in high school. In Florida. I was going from English to Computer Math class when it launched. I was able to watch the whole thing unfold live, simply by looking up. I had watched nearly every shuttle launch at the time in person and knew immediately that something had gone horribly wrong. Most of my fellow students didn't believe it until we got to class and were able to turn on the tv there. Didn't get much school work done that day.

 

I was out at the barn after school doing something and was told the shuttle had just exploded. I ran to the house and turned on the T.V. What a day to remember two days after my birthday.

 

I apparently watched it live but was too young to remember it.

 

I was in a Navy dentist's chair at the moment and saw the news coverage when I came out.
A shame it was the result of corner cutting, lazy ineptitude. It's a risky enough business.

 

Saw footage of the disaster on Newsround on Children's BBC. Apparently Newsround was the first news programme to break the story of the disaster in the UK.

 

Except that engineers who knew better had foresight of a disaster.

http://www.npr.org/sections/thetwo-...ster-challenger-engineer-still-blames-himself

 

Don't think it's fair that Bob Ebeling blames himself - he warned them, they wouldn't listen - there's not much else he could have done (I guess he could have gone to the media but even that might not have changed things).

It's a pity that he's been burdened with the guilty. It would be only just if those who were admant that the shuttle launch also suffered because at the end of the day they are the ones ultimately responsible.

And you have to wonder if there was any political pressure either direct or implicit to have the shuttle in order for the SOTU address.

 

There was a persistent rumour that someone very senior in the administration put pressure on NASA to launch that day. Unconnected, but in apparent synchronicity, the O-rings on my bath trap failed that morning due to an extreme cold snap in the UK.

 

I remember that I was in bed and my grandmother woke me up. She'd been watching the morning news and promptly got out of bed and called me downstairs so I could see the coverage. I was glued to the TV that day, and I remember feeling really angry at the ones who insisted on launching when it was so obviously unsafe.

 

The Saturns--which could have been sustained (we were looking at even larger post Saturn LVs after all)
--esp the Saturn I-B were killed because they were Army rockets. The segmented solid tech was used first with the Titans, then as just de-facto RATO units for an orbiter with a drop tank.

I would have liked the Saturn Shuttle concepts. With Energiya Buran--you don't have either the Challenger Disaster or Columbis. Energiya needed no oxygen ramp for ice/foam to break off.

The wrong country made the right shuttle--and vice versa.

 

One might wonder. But if one reviews the evidence, one learns there wasn't. Diane Vaughan's The Challenger Launch Decision remains the best study of why this particular decision was made this particular way; it must be read by anyone who wants to have an informed position.

There's no summarizing Vaughan's thesis in the confines of a TrekBBS post. She needed hundreds of pages for it herself. But the essence is one familiar to any organization that's --- with the best of intent --- caused a disaster. The shuttle group had a need to launch shuttles; the evidence that there was a serious problem with the O-ring design was weak, and obscured by confounding data; people attempting to warn that the danger was bigger than it was perceived to be had no coherent answer to the question ``you thought this was safe before; what evidence has changed your mind?''; a long string of successes had left the organization more confident that it understood the system than it actually did.

The specifics vary, but most of the same kinds of pressures can be found in any technological disaster. (And many other kinds, come to it.)

 

Say what? Their answer had been coherent and straightforward: they believed it was too cold, and it was significantly colder than it had ever been before.

 

"For a successful technology, reality must take precedence over public relations, for Nature cannot be fooled." -- Richard Feynman's famous concluding remark in Personal Observations on the Reliability of the Shuttle.

http://www.edwardtufte.com/bboard/q-and-a-fetch-msg?msg_id=0002gi

 

And the evidence that cold was a problem was ... ?

At the time, the worst O-ring erosion problem to date had happened during the coldest launch, yes. But the second-worst O-ring erosion had happened during one of the warmest launches. If cold causes O-ring erosion, then why does warmth also cause it? Since O-ring erosion --- based on the data available at the time --- seems to happen in random places on the booster, and in amounts not related to launch temperature, why conclude that launch temperature is relevant? What is the data?

In hindsight, yes, the data was there. It could have been organized and presented in a way that made a compelling case that temperature was a critical factor. (Most plausibly: every launch below a particular temperature --- I forget which; let's say 55 degrees --- had significant O-ring erosion. Only one above that temperature had significant erosion.) But it was not recognized and not understood. And as a result, the answer to the question ``you thought this was safe before; why have you changed your mind?'' went lacking a compelling answer.

 

Didn''t several Morton Thiokol engineers recommend against launch due to concerns about the cold, and were overruled pressured into changing their minds by managerment.

 

Yes, that's what I remember from what I read and heard back then.

Some other things I heard was that a major reason for management pressuring them was because they didn't want negative PR from postponing the launch.

Well, they got negative PR anyway. And seven dead astronauts.

 

Given that managers ignored the engineers' recommendation, I suppose you could twist that around and say that the data was not recognized and understood. If you ignore something, then you don't recognize it and you don't understand it, sure, from a certain point of view.

According to this, enough data to conclude that the launch was going to be irresponsibly dangerous was available and presented; it was simply ignored. From http://www.nasaspaceflight.com/2007/01/remembering-the-mistakes-of-challenger/:

And, let's look at the overall context. There was no certification to launch in temperatures that cold. NASA knew that Morton-Thiokol was concerned about temperatures that low. The presentation that took place was under extreme time pressure to address that concern. If you're going to expect polish in a presentation on whether a program that had been operating for years could now safely operate under conditions that it had never been certified to operate under before, then you give the group making the presentation more than just the few hours they [the Morton-Thiokol group] had to throw something together. To then pick at the presentation made under such circumstances and fault it for a lack of coherence or a lack of organization, that's abominable.

Also, your post contains a logic error. You said, "If cold causes O-ring erosion, then why does warmth also cause it?", as if that's a question that would even need to be answered under the circumstances. The relevant information is granted right there in the hypothesis, "cold causes O-ring erosion." According to the source I quoted, there was convincing data presented to conclude that under the prevailing cold conditions, adequate seals wouldn't form. You don't need to go off on a red herring and also answer why adequate seals hadn't formed under other conditions, because that couldn't change the fact in front of you, that they wouldn't form under the prevailing conditions.

 

There were other shuttles that almost didn't make it back. I forget which one it was, but it was sprayed with pellets of tank foam on the way up and the damage was really obvious. The crew was even informed in space that they had a good chance of not making it back. I remember reading the pilot having said that if it were clear that was the case, he was going to get on the radio and let NASA know just what he thought of how they run the space program. Anyway, it landed safely, with all of these black and dark streaks all over it, as if it passed through a meteor shower. This is only something I've read about ...