posted
Tonight, on the 11 pm newscast, there was new footage of the Columbia entering the atmosphere. Prior to what many on the ground saw as an explosion, a large vaguely rectangular white object is seen behind the shuttle. This is believed to be a component of the shuttle.
Looking at a model of the shuttle, the only piece which I think is large enough to be seen from the ground and resembles the piece are the cargo bay doors.
I am speculating here. As the ship was entering the atmosphere, her left cargo bay door was blown clear of the hull. This reduction in weight, I am assuming the door has weight, altered the balance in the shuttle's flying capablities. The ship's onboard computers attempted to correct the situation until eventually she was destroyed.
Is this plausible?
Don't the cargo bay doors have sensors?
Registered: Sep 2002
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posted
A gut feeling only, not an expert opinion, but the loss of a cargo bay door might indeed lead to the sort of prolonged death scene that took place, and not immediate disintegration. After all, the shuttle is coming down belly first and does not depend on a smooth airflow over the upper surfaces.
Still, I'd think several sensors would indeed tell if the door departed. Not to mention the flight deck crew should notice that the windows *behind* them suddenly lit up like the ones *in front*!
Any data on how the moment of the object's appearance coincides with the reports and telemetry from the orbiter?
The shuttle is approaching California. As she neared California and could be seen in the San Francisco Bay Area, the object separated from the shuttle. Nearing to Arizona, passing over southern California and visible to LA, there is a flaring of the shuttle. (I don't know what would cause a shuttle to flare like this. Some on the ground interpreted it as an explosion occuring on the shuttle.) Over Arizona and New Mexico, the brake lines fail, the temperature sensors record increases in heat, and the computer attempts to compensate for movement in the left wing. Between New Mexico and Texas, according to satellite photographs, this is the point when the destruction was at its worst. Above western Texas, the shuttle is destroyed and the fragments propelled by momentum are crashing into the ground in eastern Texas.
Though not exact to a timetable, this is the general sequence of events I have pieced together from accounts.
SENSORS
I know there are heat sensors in the wings. There has been less discussion on the question of sensors in the bay and/or near the bay.
AWARENESS
The small windows to the cargo bay area are on the flight deck. On the re-entry, four of the astronauts are strapped into seats facing forward. They are buckled tightly. (The other three astronauts are on the second deck, located below the flight deck. There are no windows on this deck.)
Registered: Sep 2002
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posted
Loss of a cargo bay door SHOULD have been a significant sensor awareness event. Sensors are used to verify that the bay doors are firmly locked down prior to descent, and consequently would alert the crew if this was not the case during reentry. The payload bay doors are primarily made of lightweight and very stiff composite materials and it is not unlikely that they would be the first components to be torn away if the shuttle lost flight control. Basically, the payload bay door "might" have been the first thing to break free, but as a result of loss of control...and probably not the cause.
Just to head off a future question probably, the payload bay is not pressurized and is designed to vent during ascent and descent so I doubt any pressurization alerts would have been available.
Registered: Mar 1999
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Unfortunately, there are no videos of the shuttle farther west than the San Francisco Bay Area. I suppose if there, we might have a clearer vison of what were the initial stages.
Shipbuilder,
What could cause the shuttle to flare? Any ideas.
Registered: Sep 2002
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"After all, the shuttle is coming down belly first..."
I seem to recall hearing that it wasn't, though. That it was far closer to nose-first than it should have been. But I heard that the day after the accident, so maybe it's something that was later refuted...
Registered: Mar 1999
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posted
There is new footage from the USAF. Their cameras are more sensitive than the video cameras of civilians. In the footage, a gash is seen between the wing and the fuselage. And, I just heard on the news, an important piece of the wing assemblage was recovered near Fort Worth, Texas.
Registered: Sep 2002
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SPECULATION: A "flare" as Epoch stated is an indication of something burning, it could be from the external heat (TPS burn-through) or even possibly an internal explosion. You can see during the breakup footage a couple of differnt flares within the wreackage, this is most likely the RCS, OMS, or APU fuel supplies being ignited.
As for the shuttles attitude during descent it is typically nose up until it enters the energy bleed off stage of descent where it performs a series of maneuvers to bleed off excess velocity (akin to fishtailing in a speeding car to slow it down). Some of the CNN graphics show these maneuvers pretty well, where the shuttle begins to bank in opposite directions. What you have to realize is that at those velocities, even a slight deviation in attitude (atleast those not specified by the flight control system) puts a tremendous amount of load on structures that weren't designed to handle them....the result of this happening was seen in the rapid breakup.
Registered: Mar 1999
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