Challenger

They were nervous, rightly so. But it’s not the outside air temperature that matters, it’s the temperature of the o-rings.

The main issue is that what NASA had was a developmental system, with all sorts of unknowns, and they were trying to run it as though it was a well-understood production system.

Apollo had delivered amazingly—men on the moon in 9 years, starting with modified ICBMs! The cultural impact of that was very large—not only did it fix the US’s Sputnik problem and reassure their allies (which was the point of the exercise), but it changed everyone’s attitude towards the Earth itself.

To my eye, that “Earthrise” photo has had more lasting influence than all the trudging around up there.

Naturally—NASA being a big government agency and therefore having pathological incentives—they reacted by asking for the sky: enough dough for a permanent space station, a Mars mission, and a fleet of space trucks to get all that stuff to and from orbit.

Under severe budget constraints (for NASA, at least), they canceled all of it except the truck fleet. Then they got some fancy consultants (Mathematica Inc., no relation to Wolfram & Co.) to make a plan for 60 launches per year using 6 shuttles, with mostly commercial payloads, so that they could afford to build them.

Eventually they managed nine launches per year, mostly military, and instead of being everyone’s idol and independently wealthy, they were begging for money and firmly under the thumb of the Air Force.

Meanwhile, they were trying to learn how to make and run the spacecraft. They did it by the book, with a very highly organized system of flight reviews and engineering criteria that allowed them to apply uniform standards of evidence and decision-making to a wildly multifarious effort.

The workings of this system, and the people who made it work so well almost all the time, are what Vaughan’s book is about, and what makes it so fascinating.

What bit them in the end was that Thiokol wasn’t able to show a good statistical correlation between O-ring erosion and the calculated temperature. It got worse at low temperature, of course, but there was this one launch where the rings were at 80 degrees or something, yet which had the largest erosion to date.

Least squares analysis is very sensitive to outliers, so that one data point destroyed the calculated correlation. The procedure required firm data to delay the launch, and Thiokol didn’t have it. That’s how you run a well-understood production system: You learn by doing, and make adjustments based on accumulated experience. They were very good at that.

Because the shuttle was really a developmental system, though, the procedures for making those adjustments actually pushed the SRBs closer to disaster with each anomaly.

I can’t do justice to it here, but the way this whole team of highly competent people, who followed all the rules of the system conscientiously, nevertheless caused a disaster, is a story right out of Greek tragedy.

Cheers

Phil Hobbs

They weren't being killed intentionally.

In your singularly inexpert opinion.

So what. That's how the world works, and clown like you are lot of the problem.

Not really. We've been observing the CO2 level in the atmosphere continuously since 1958 and Manua Loa wasn't NASA.

The entirely independent Cape Grim observatory got going in 1976 - it's run by Australia's CSIRO

NASA estimate of how many shuttles' they'd lose were just that - they dated back to before they'd lost any.

You objections to the thoroughly reliable climate data involve your demented conspiracy theory which has everybody involved in taking the published the measurements consistently lying to the public for more than sixty years.

Nobody even thought that anyone would bother until around 1990, when global warming hit statistical significance, and the fossil carbon extraction industry woke up the threat to their long term cash flows.

I'm still inclined to believe that the suits pressured the engineers into compliance with something that they were deeply uncomfortable with

- namely launching when the ambient temperature was so far below the norm in Florida. They had a nationwide TV tie in and VIPs to impress. The show must go on...

So they got a lot more of a spectacle than they had bargained for.

Likewise with the Columbia disaster where they essentially refused to call in a favour off the military imaging kit operators that could have looked at the vehicle's leading edge for signs of damage.

That time they convinced themselves that because it (foam impacts) had happened before with no ill effects it would be OK again this time. ISTR an intern was tasked with the first impact analysis. It did get escalated but not far enough up the hierarchy to make a difference.

HST mirror by PE also suffered from a painstakingly exact measurement process that created a fabulously smooth polished mirror using very sophisticated methods but precisely figured to the wrong shape.

These things happen due to human fallibility and plain bad luck. The backup Kodak mirror was correct in every detail but never flew.

ISTR at least one Morton Thiokol engineer was begging them not to launch with it so cold but was over ruled by more senior people in the end.

Rocket launches and landings are intrinsically dangerous. On this I am inclined to agree with JL - unless and until we find something that our robotic and AI kit cannot do we shouldn't be sending people into space.

It was the *only* way to explore the moon back in 1969 but not any more...

Read the book if you have the chance.

Space exploration has little value outside its cultural impact.

Cheers

Phil Hobbs

Big institutions tend to be immoral. Money and power dominate honest engineers.

Remember "Don't be evil" ?

We coud have put robots on the moon in 1969. The astronauts were mostly passive passengers anyhow.

The Shuttle's raw reliability was likely about 1 vehicle loss in 100 and it pushed the limits of the tech of the time so much it would probably haven been difficult to get it much better than that that without hundreds of flights to learn from. They did 135 launches with 2 losses, par for the course.

If it hadn't been the O-rings and TPS it probably would have been one of the dozens of other must-work systems on the ship. I think there had to be some level of institutional delusion about what the fundamental reliability of the thing was to have a program at all.

The list of anomalies from STS-1 is long, most of them minor, a couple of them very severe. It was crazy to some degree to launch it the first time and if it were built today it likely would've undergone years more simulation and static testing but they felt they were at the limit of what could be tested at the time with the technology and budget they had.

Here in 2024 God only knows how many Starships Mr. Musk is going to blow up on test flights, before they figure it's safe enough to put anyone on.

The shuttle was a dual-use vehicle, it could've made a formidable weapon in a pinch. The Soviets thought so, at least.

The large crossrange from the delta wings made once-around space bomber missions north from Vandenburg feasible, though IIRC they never launched from there.

The DOD didn't "force" the delta wings, exactly, crossrange was a desire of theirs that NASA eventually came around to as beneficial in general, it made another abort mode possible and simplified design calculations/simulations to be tractable with the tech available at the time.

But it's likely if they couldn't have come to a path of convergent evolution then the project wouldn't have gone forward at all.

The Soviets were very concerned about the possibility of a decapitating US first strike in the late 70s and early 80s and took Reagan to be a madman (they weren't half-wrong.)

At least an ICBM launch is unambiguous, what do you do when a scientific vehicle/bomb truck launches northbound during a period of tension, with its payload concealed.

What's going on? Is it a test flight? Are they launching a spy satellite? Are they carrying a rack of nuclear bunker-busters to drop straight on our heads? Do we assume that and try to shoot it down and maybe start a war that way, or wait for the first strike to land on us? Unpleasant choices...

Sorry, Bill. I've got better things to do than get drawn into another of your pointless pissing contests.

Lying about the science evidence demonstrating that climate change is happening is a well-paid commercial activity. You aren't remotely good enough at it to get paid for it, but that doesn't seem to stop you hoping that you might.

And this will continue to be true until we find something interesting. The nature of exploration is that we don't know what we will find until we find it.

Residents of Australian find it perfectly sensible that people kept poking around the Pacific until Cooke found Australia and mapped enough of it to suggests that it might be worth establishing a colony there.

Most the residents of North America with European ancestry would think much the same about Columbus and his daft misconceptions about the size of the earth, if they thought about the matter at all.

They aren't even immoral. They just have inflexible procedures.

Why bother? It's just one more corporate slogan.

But the robots wouldn't have been up to much.

Having people with names and faces up there made the newspaper and TV reports much more interesting to the general public and created the cultural effect sought.

Nice try, Bill, but I'm not falling for it. I know a barb when I see it and I'm not getting hooked. Try plying your trade on some other poor sap.

You've gotten well hooked by climate change denial propaganda, and thrashing around pretending to be sceptical is just more of your futile attempts to evade the point. The barb is deeply embedded. You probably need a brain implant to get off the hook, and you'd probably reject functional brain tissue as incompatible with your right-wing goof genome.

Nope. Still not tempted. You need to up your game, Bill.

For a brain dead creep like you? You do like to make your fantasies thoroughly implausible, but this is even sillier than usual.

Bill Sloman, Sydney