I spent a good part of this morning watching Challenger: The Final Flight, a four-part Netflix docuseries that unpacks the 1986 Challenger disaster. We’ve all sunk into that memory over and over — it was the 9/11 of the ’80s. I was in my pre-war bungalow apartment on High Tower Drive, watching the launch like everyone else, and I distinctly recall KNBC’s Kent Shocknek saying “my God” when the booster rocket exploded. (Stunned into silence, the NBC network moderator kept his yap shut for quite a while.)

The good news is that series creators Steven Leckart and Glen Zipper have told (nearly) the whole story with sustained narrative tension and surgical clarity, and with just the right amount of melancholy. But to be honest, the first three episodes mostly feel like a rehash of the familiar. An excellent rehash, but we’ve all seen the footage, watched the anniversary reports, read the books and articles. Everyone born before 1975, I mean.

But the fourth chapter, titled “”Nothing Ends Here”, is the payoff. For this is the episode in which the good guys and bad guys have their big showdown — the Morton Thiokol engineers who warned about the lethal combination of O-rings and frigid weather and at least tried to warn about a possible disaster, and the upper-level NASA assholes, particularly the obstinate NASA Marshall Space Flight Center director William Lucas and the deplorable Lawrence Mulloy, who worked right under Lucas.

Lucas and Mulloy are the ones who basically killed Christa McAuliffe and the other six shuttle astronauts. As N.Y. Times reporter David E. Sanger puts it, “This wasn’t really an accident at all…this was more like manslaughter.”

The do-or-die moment is explored in episode three, when a prelaunch conference call between NASA officials and leaders at Morton Thiokol happened on 1.27.86 — the night before. Every Morton Thiokol engineer agreed that the rubber O-rings in the rocket boosters might buckle or contort due to the icy temps during that final week of January ’86. But Morton Thiokol honchos and NASA higher-ups wanted the launch to happen, and that was the name of that tune.

Present-tense Mulloy, who looks like he’s dying of cancer while suffering the spiritual pains of hell, insists that “the data did not support the recommendation that the engineers were making.” A Morton Thiokol guy concurs by saying “we couldn’t prove that [the O-ring erosion] would happen…we could not do that.”

But another engineer says that he told participants that the Challenger “should not launch in temps below 53 degrees fahrenheit.” In response Mulloy reportedly said, “Good God, when do you want us to launch, next April?”

Lucas’s definitive declaration: “I was aware of the concerns about the O-ring seals…my assessment was that it was a reasonable risk to take….I did not think it was a problem sufficient to ground the fleet.”

Mulloy’s final line: “I feel I was to blame, but I feel no guilt.”

Does the doc pass along the consensus view that the seven astronauts were almost certainly not killed by the explosion, and were most likely conscious all through the big long fall, and died from blunt trauma when their passenger compartment slammed into the ocean? Of course not.