As some might reckon it, the beginning of the end for NASA's space shuttle program came 10 years ago Friday, at 8:48:39 a.m. EST on Saturday, Feb. 1, 2003.
That's when strain gauge V12G9921A, a sensor in the shuttle Columbia's left wing, began registering a small but unusual increase in stress as the spaceplane descended from orbit to close out its 28th mission. Twenty seconds later, a temperature sensor followed suit.
Over the next few minutes, a shuttle data recorder captured a cascade of alarming sensor readings and failures on the left side of the spacecraft that clearly indicated a rapidly unfolding catastrophe.
It played out in a brutal rush. Just 10 minutes and 53 seconds after that initial strain gauge reading, as the shuttle streaked across the heartland of America, commander Rick Husband was cut off in mid transmission, presumably when the spaceplane veered out of control at Mach 18, breaking apart less than a minute later.
It was 9:59:32 a.m. It would take another two-and-a-half minutes or so for the harsh reality of Columbia's demise to reach the Kennedy Space Center where family members, NASA managers, the ground support team, reporters and photographers were standing by for the shuttle's homecoming.
I was covering Columbia's re-entry from the CBS News bureau at the Florida spaceport, polishing up a post-landing mission wrap-up story that I planned to post to the web within a few minutes of touchdown.
Listening to NASA television in Florida, I had no idea the shuttle was in trouble. I had heard Husband's interrupted transmission, but air-to-ground drop outs were not unexpected during shuttle entries. Still, this one seemed to be lasting longer than usual and I was beginning to feel a bit anxious.
Then, at 9:02 a.m., Justin Ray, a reporter with Spaceflight Now, forwarded an instant message from Stephen Clark, a space enthusiast (now veteran space reporter) who was watching Columbia fly overhead southeast of Dallas.
I will never forget that message and the sudden chill that settled over me as I read it:
Clark: O M G!!!!!!!!!!!!!!!
Clark: DUDE OMG
Clark: It broke up!
Clark: The shuttle broke up!
Ray: He's in Texas
Harwood: Are you serious?
Ray: North of Houston
For a moment, I couldn't move. Clark was a veteran shuttle watcher and I did not doubt his observation. I simply stared at the computer screen for a few seconds, coming to grips with what those words meant, thinking of Husband and his crew, wondering if they were still alive but fearing the worst.
As it turned out, the astronauts almost certainly were already dead, killed by rapid decompression when the crew module broke away from the fuselage and disintegrated high above central Texas.
Over the days, weeks and months that followed, the Columbia Accident Investigation Board uncovered a now-familiar history of external tank foam insulation problems, management miscues and poor internal communications that contributed to the mishap.
As we would learn during the course of the investigation, Columbia sustained its fatal wound 16 days earlier when a briefcase-size chunk of foam insulation fell away from a so-called bi-pod ramp on ship's external tank 81.7 seconds after liftoff.
The lightweight foam slowed rapidly in the supersonic flow and the shuttle, racing skyward at more than 1,500 mph at that point, ran into it at a relative velocity of about 545 mph. The impact blasted a large hole, possibly 6 inches across or wider, in one of the protective heat shield panels making up the left wing's leading edge.
The reinforced carbon carbon making up the shuttle's nose cap and wing leading edge panels experiences the most extreme heating during re-entry, some 3,000 degrees Fahrenheit during the 15-minute zone of "peak heating" just after the orbiter falls back into the discernible atmosphere.
Put simply, the gaping hole in Columbia's wing was not survivable. From that perspective, the beginning of the end was the foam strike and not its inevitable consequence.
But some believe Columbia's crew could, in fact, have been saved if NASA management had recognized the severity of the problem soon enough to mount an emergency rescue flight.
Engineers analyzing launch photography clearly saw the foam fall from the tank. But they could not see where it struck. From the tracking camera's perspective, the debris disappeared below the left wing and emerged as a cloud of white powder. There was no question it had hit the wing. The question was where? And how much damage had it caused?
A few alarmed shuttle engineers lobbied NASA management to ask the Air Force or the National Reconnaissance Office to aim a spy satellite at the shuttle for a detailed photo inspection. But NASA managers in Florida and Texas rebuffed those efforts and settled instead for an in-house analysis based on computer modeling and past experience.
The engineers assigned the task ultimately concluded the foam strike did not represent a "safety of flight" issue. NASA's Mission Management Team, while concerned about what repairs or modifications might be required for downstream external tanks, dismissed the incident as a concern for Columbia.
And besides, the common wisdom went, without a robot arm and some kind of repair kit, there were no viable options to repair serious heat shield damage. As MMT Chairman Linda Ham famously said at one point, "it's not really a factor during the flight because there is not much we can do about it."
Ham later came under intense criticism during the course of the accident investigation for her quick, seemingly uncritical acceptance of the foam strike analysis.
But Ham did not act in a vacuum and there were many engineers and managers up and down the chain of command who had an opportunity to lodge an objection. While concerns were raised in some quarters, no one stood up and publicly challenged the conclusions of the engineering analysis.
And by that point, as a NASA's analysis would later show, there was nothing Ham or the MMT could have done to save the crew.
While it was theoretically possible to launch the shuttle Atlantis on a rescue mission, it would have required an almost instant awareness of the severity of the problem with Columbia, a decision to commit a second shuttle to flight before the cause of the first failure was known and a willingness to cut corners to get Atlantis off the ground before Columbia ran out of power and air.
And even then, it would have required an enormous amount of luck, with no delays due to technical snags or even bad weather.
But it was theoretically possible, and many within the program regret to this day that NASA did not at least make an attempt. I don't believe it had any realistic chance of success, but as others have said before me, not even trying guaranteed it.