Celebrity Death Thread

[Islair]

I think I was in 2nd grade. One of my friends Mom was the school secretary, and the office had the only TV in the building. We made up some excuse, to go to the bathroom or something, and went down to the office to watch the launch instead.

We were behind the big wooden desk in the office watching that small TV screen, and when the shuttle blew we were just standing there, mouths hanging open, and her Mom told us to go back to class. To try and not tell anyone what we saw, but being in 2nd grade, we held onto our secret for about 5 seconds. When our teacher heard us talking about it she thought we were making up stories and lying, she had to go to the office to confirm our story.

[Drew]

I was at Rockville Iceland. It was a cold sunny day after a big snowfall. I watched it from the dayroom in our dormatory.

[Malto Marko]

I was at work. We had the TV on and one of my employees called me over to watch.

I stood there in watching in disbelief then an overwhelming feeling of grief came over me and took about an hour before I could carry on a conversation with someone.

[Chuck Cunningham]

In University in London, Ontario at the time. My mother who lived in Daytona Beach at that time actually saw the explosion from her balcolny!

[kayrone]

I was a senior in high school, and that semester I didn't have a class for 4 th or 5 th hour, so I always went home and watched tv - I remember being pissed that they interrupted my soap to show the takeoff, but as a result I saw it blow up on live tv and remember the feeling of complete disbelief, as if my eyes were playing tricks on me or something.

[Marko69]

I was at a job in Cathcart Place in Edinburgh. Steve Wright in the afternoon show on Radio one was on..... The song playing was "The sun always shines on TV" by A-HA, and it was stopped halfway through to bring us the breaking news. I was in a sort of mini shock on hearing it. Then the footage on TV later that night made me very emotional. Horrible day.

[MiamiTreo3]

I was always fascinated by flying of any form. I was in the sixth grade and was sent out of class because I had finished my work and usually started disturbing others.( I have ADHD) I went to the library just as it blew up. I didnt relize what was going on right away. It was always something I thought about over the years. Very surreral

[Marko69]

TREO...., SIT DOWN FFS, STOP FIDGETTING MAN.

It's ok bud, my cousin has it....., he says hes lived his life hearing that.

[Tony G]

I had driven up to my folks place and was there alone when my brother came in. He said he'd heard the shuttle had just exploded, he heard it in the line he was in at the store. I thought there was no way, it may have had a problem but there was a good chance the crew could survive if the shuttle could detatch. We turned on CNN and waited for them to show a replay. We joined as they were showing Krista Mcauliffe's parent's reaction. A few minutes later they showed the replay and I knew they were done. Amazingly, and perhaps horrifying as well, it appears the crew survived the explosion and was killed on impact with the water.

[YT]

I was at Travis AFB and a friend woke me up to go watch the launch in his room. We're sitting there (about 8 of us) when it blew up.

A few years later after getting into accident investigation I read everything I could find on it. There was also a re-enactment about what caused the accident on Discovery or one of the other science channels.

The company that manufactured the o-ring (Thyssen-Krupp) failed to tell NASA about the potential for failure of the o-ring due to freezing temps. One of the engineers fought his bosses to tell NASA and was told "Take off your engineers hat and put on you managers hat".

Essentially, T-K deliberately withheld info from NASA so they wouldn't lose money by having to fix the the o-ring problem.

[DanO]

Boy, I find that hard to believe, YT. The scenario you layed out is quite believable as we all know but given the magnitude of the situation I can't believe this wouldn't have come to light. Just saying.

"Amazingly, and perhaps horrifying as well, it appears the crew survived the explosion and was killed on impact with the water."
----------------------I'd forgotten they suggested that. Seems so improbable.

[Tony G]

Boy, I find that hard to believe, YT. The scenario you layed out is quite believable as we all know but given the magnitude of the situation I can't believe this wouldn't have come to light. Just saying.

It did come to light.

Thiokol-NASA conference call

Forecasts for January 28 predicted an unusually cold morning, with temperatures close to 31 ?F (−1 ?C), the minimum temperature permitted for launch. The low temperature had prompted concern from Thiokol engineers. At a teleconference on the evening of January 27, Thiokol engineers and managers discussed the weather conditions with NASA managers from Kennedy Space Center and Marshall Space Flight Center. Several engineers—most notably Roger Boisjoly, who had voiced similar concerns previously—expressed their concern about the effect of the temperature on the resilience of the rubber O-rings that sealed the joints of the SRBs, and recommended a launch postponement.[11] They argued that if the O-rings were colder than 53 ?F (12 ?C), they did not have enough data to determine whether the joint would properly seal. This was an important consideration, since the SRB O-rings had been designated as a "Criticality 1" component, meaning that there was no backup if both the primary and secondary O-rings failed, and their failure would destroy the Orbiter and its crew.

Thiokol management initially supported its engineers' recommendation to postpone the launch, but NASA staff opposed a delay. During the conference call, Hardy told Thiokol, "I am appalled. I am appalled by your recommendation." Mulloy said, "My God, Thiokol, when do you want me to launch — next April?"[11] One argument of NASA personnel in contest to Thiokol's concerns was that if the primary O-ring failed, the secondary O-ring would still seal. This was unproven, and was in any case an illegitimate argument for a "Criticality 1" component. As astronaut Sally Ride cited in questioning NASA managers before the Rogers Commission, it is forbidden to rely on a backup for a "Criticality 1" component. The backup is there to provide redundancy in case of unforeseen failure, not to replace the primary device, leaving no backup.

NASA did not know of Thiokol's earlier concerns about the effects of the cold on the O-rings, and did not understand that Rockwell International, the shuttle's prime contractor, viewed the large amount of ice present on the pad as a constraint to launch. Because of NASA's opposition, Thiokol management reversed itself and recommended that the launch proceed as scheduled.[11][12]

[Tony G]

The following account of the accident is derived from real time telemetry data and photographic analysis, as well as from transcripts of air-to-ground and mission control voice communications.[14] All times are given in seconds after launch and correspond to the telemetry time-codes from the closest instrumented event to each described event.[15]

Until liftoff actually occurs, the Space Shuttle main engines (SSMEs) can be safely shut down and the launch aborted if necessary. At liftoff time (T=0, which was at 11:38:00.010 EST), the three SSMEs were at 100% of their original rated performance, and began throttling up to 104% under computer control. At this moment, the two SRBs were ignited and hold-down bolts were released with explosives, freeing the vehicle from the pad. With the first vertical motion of the vehicle, the gaseous hydrogen vent arm retracted from the External Tank (ET) but failed to latch back. Review of film shot by pad cameras showed that the arm did not re-contact the vehicle, and thus it was ruled out as a contributing factor in the accident.[15] The post-launch inspection of the pad also revealed that kick springs on four of the hold-down bolts were missing, but they were similarly ruled out as a possible cause.[16]

Later review of launch film showed that at T+0.678, strong puffs of dark gray smoke were emitted from the right-hand SRB near the aft strut that attaches the booster to the ET. The last smoke puff occurred at about T+2.733. The last view of smoke around the strut was at T+3.375. It was later determined that these smoke puffs were caused by the opening and closing of the aft field joint of the right-hand SRB. The booster's casing had ballooned under the stress of ignition. As a result of this ballooning, the metal parts of the casing bent away from each other, opening a gap through which hot gases—above 5,000 ?F (2,760 ?C)—leaked. This had occurred in previous launches, but each time the primary O-ring had shifted out of its groove and formed a seal. Although the SRB was not designed to function this way, it appeared to work well enough, and Morton-Thiokol changed the design specs to accommodate this process, known as extrusion.

While extrusion was taking place, hot gases leaked past (a process called "blow-by"), damaging the O-rings until a seal was made. Investigations by Morton-Thiokol engineers determined that the amount of damage to the O-rings was directly related to the time it took for extrusion to occur, and that cold weather, by causing the O-rings to harden, lengthened the time of extrusion. (The redesigned SRB field joint used subsequent to the Challenger accident uses an additional interlocking mortise and tang with a third O-ring, mitigating blow-by.)

On the morning of the disaster, the primary O-ring had become so hard due to the cold that it could not seal in time. The secondary O-ring was not in its seated position due to the metal bending. There was now no barrier to the gases, and both O-rings were vaporized across 70 degrees of arc. However, aluminum oxides from the burned solid propellant sealed the damaged joint, temporarily replacing the O-ring seal before actual flame rushed through the joint.

As the vehicle cleared the tower, the SSMEs were operating at 104% of their rated maximum thrust, and control switched from the Launch Control Center (LCC) at Kennedy to the Mission Control Center (MCC) at Johnson Space Center in Houston, Texas. To prevent aerodynamic forces from structurally overloading the orbiter, at T+28 the SSMEs began throttling down to limit the velocity of the shuttle in the dense lower atmosphere, as per normal operating procedure. At T+35.379, the SSMEs throttled back further to the planned 65%. Five seconds later, at about 5,800 metres (19,000 ft), Challenger passed through Mach 1. At T+51.860, the SSMEs began throttling back up to 104% as the vehicle passed beyond Max Q, the period of maximum aerodynamic pressure on the vehicle.

Beginning at about T+37 and for 27 seconds, the shuttle experienced a series of wind shear events that were stronger than on any previous flight.[17]

At T+58.788, a tracking film camera captured the beginnings of a plume near the aft attach strut on the right SRB. Unknown to those on Challenger or in Houston, hot gas had begun to leak through a growing hole in one of the right-hand SRBs joints. The force of the wind shear shattered the temporary oxide seal that had taken the place of the damaged O-rings, removing the last barrier to flame rushing through the joint. Had it not been for the wind shear, the fortuitous oxide seal might have held through booster burnout.

Within a second, the plume became well defined and intense. Internal pressure in the right SRB began to drop because of the rapidly enlarging hole in the failed joint, and at T+60.238 there was visual evidence of flame coming through the joint and impinging on the external tank.[14]

At T+64.660, the plume suddenly changed shape, indicating that a leak had begun in the liquid hydrogen tank, located in the aft portion of the external tank. The nozzles of the main engines pivoted under computer control to compensate for the unbalanced thrust produced by the booster burn-through. The pressure in the shuttle's external liquid hydrogen tank began to drop at T+66.764, indicating the effect of the leak.[14]

At this stage the situation still seemed normal both to the astronauts and to flight controllers. At T+68, the CAPCOM Richard O. Covey informed the crew that they were "go at throttle up", and Commander Dick Scobee confirmed the call. His response, "Roger, go at throttle up," was the last communication from Challenger on the air-to-ground loop.
Vehicle breakup
Challenger breakup (346 kB, ogg/Theora format)
Challenger begins to disintegrate.

At T+72.284, the right SRB apparently pulled away from the aft strut attaching it to the external tank. Later analysis of telemetry data showed a sudden lateral acceleration to the right at T+72.525, which may have been felt by the crew. The last statement captured by the crew cabin recorder came just half a second after this acceleration, when Pilot Michael J. Smith said "Uh oh."[18] Smith may also have been responding to onboard indications of main engine performance, or to falling pressures in the external fuel tank.

At T+73.124, the aft dome of the liquid hydrogen tank failed, producing a propulsive force that pushed the hydrogen tank into the liquid oxygen tank in the forward part of the ET. At the same time, the right SRB rotated about the forward attach strut, and struck the intertank structure.

The breakup of the vehicle began at T+73.162 seconds and at an altitude of 48,000 feet (15 km).[19] With the external tank disintegrating (and with the semi-detached right SRB contributing its thrust on an anomalous vector), Challenger veered from its correct attitude with respect to the local air flow and was quickly torn apart by abnormal aerodynamic forces, resulting in a load factor of up to 20 (or 20 g), well over its design limit of 5 g. The two SRBs, which can withstand greater aerodynamic loads, separated from the ET and continued in uncontrolled powered flight for another 37 seconds. The SRB casings were made of half-inch (12.7 mm) thick steel and were much stronger than the orbiter and ET; thus, both SRBs survived the breakup of the space shuttle stack, even though the right SRB was still suffering the effects of the joint burn-through that had set the destruction of Challenger in motion.[16]

The more robustly constructed crew cabin and SRBs survived the breakup of the launch vehicle; while the SRBs were subsequently detonated remotely by the Range Safety Officer, the detached cabin continued along a ballistic trajectory, and was observed exiting the cloud of gases at T+75.237.[16] Twenty-five seconds after the breakup of the vehicle, the trajectory of the crew compartment peaked at a height of 65,000 feet (20 km).[19]

The Thiokol engineers who had opposed the decision to launch watched the events on television. They believed that any O-ring failure would have occurred at liftoff, so were happy to see the shuttle successfully leave the launch pad. At about one minute after liftoff, a friend of Boisjoly said to him "Oh God. We made it. We made it!" Boisjoly recalled that when the shuttle exploded a few seconds later, "we all knew exactly what happened."[11]

[Tony G]

The crew cabin, made of reinforced aluminum, was a particularly robust section of the shuttle.[22] During vehicle breakup, it detached in one piece and slowly tumbled into a ballistic arc. NASA estimated the load factor at separation to be between 12 and 20 g; however, within two seconds it had already dropped to below 4 g and within ten seconds the cabin was in free fall. The forces involved at this stage were likely insufficient to cause major injury.

At least some of the astronauts were likely alive and briefly conscious after the breakup, as three of the four recovered Personal Egress Air Packs (PEAPs) on the flight deck were found to have been activated. Investigators found their remaining unused air supply roughly consistent with the expected consumption during the 2 minute 45 second post-breakup trajectory.

While analyzing the wreckage, investigators discovered that several electrical system switches on Pilot Mike Smith's right-hand panel had been moved from their usual launch positions. Fellow Astronaut Richard Mullane wrote, "These switches were protected with lever locks that required them to be pulled outward against a spring force before they could be moved to a new position." Later tests established that neither force of the explosion nor the impact with the ocean could have moved them, indicating that Smith made the switch changes, presumably in a futile attempt to restore electrical power to the cockpit after the crew cabin detached from the rest of the orbiter.[23]

Whether the astronauts remained conscious long after the breakup is unknown, and largely depends on whether the detached crew cabin maintained pressure integrity. If it did not, the time of useful consciousness at that altitude is just a few seconds; the PEAPs supplied only unpressurized air, and hence would not have helped the crew to retain consciousness. The cabin hit the ocean surface at roughly 207 mph (333 km/h), with an estimated deceleration at impact of well over 200 g, far beyond the structural limits of the crew compartment or crew survivability levels.[19]

[Malto Marko]

OK. Lots of words that, I really still have to read the last 2 posts but my question to the first is......

Even though NASA knew their launches were taking place in Florida, why weren't the specs for the seal to be at 0 F knowing that it is most unlikely and marked as a red flag for operations?