Anniversary of the Columbia Accident - January 16, 2003

Two years ago today on January 16, 2003, a piece of foam accidentally
ripped loose from the External tank. Tumbling into the supersonic
slipstream between the External Tank and Orbiter, the wedge shaped piece
of foam flew and accelerated into the Orbiter's wing. In the short time
that it took to travel between the External Tank and impact the Orbiters
wing, it had accelerated to the point where it had the energy of a man
swinging a 100 lbs sledge hammer.

While the impact was large, it didn't affect any critical systems required
for ascent, and the Astronauts made it safely into Orbit. But, the impact
with the foam had punched a hole in the Reinforced Carbon Carbon leading
edge of the wing. The Reinforced Carbon Carbon (RCC) leading edge is
essentially a high strength charcoal that can withstand the extreme
temperatures of entry. Columbia was damaged and in need of repair before
her return trip from orbit.

Initial reports of the accident came in when the film from various vantage
points around the Cape were analyzed for debris impacts. From the film it
was determined that the size of the foam was much larger than the blizzard
of small pieces of foam that the Shuttle normally flys through.
Additionally, the actual impact with the Orbiter's wing was not visible,
but it's results on the large piece of foam clearly were. The large chunk
of foam had been completely obliterated by the impact with the wing.

Clearly any damage to the Orbiter's wing was going to have to be inspected
and possibly repaired before a safe entry could be made. So, KSC personnel
in an E-mail requested pictures, stating that the exact location of impact
was unknown, but that it must have impacted the RCC leading edge or the
fragile tiles covered belly of the Orbiter.

Thus begin the chain of events that would eventually end in disaster for
Columbia and her crew sixteen days later.

Craig Fink

Craig Fink wrote:

The Reinforced Carbon Carbon (RCC) leading edge is
essentially a high strength charcoal that can withstand the extreme
temperatures of entry.

Wouldn't "graphite" be a better discription? The only winged spacecraft
I can think of that had a charcoal leading edge during reentry was that
second German A4b with the wooden wings.

Pat

On Sun, 16 Jan 2005 15:10:06 GMT, in sci.space.history, Craig Fink wrote:

Two years ago today on January 16, 2003, a piece of foam accidentally
ripped loose from the External tank. Tumbling into the supersonic
slipstream between the External Tank and Orbiter, the wedge shaped piece
of foam flew and accelerated into the Orbiter's wing. In the short time
that it took to travel between the External Tank and impact the Orbiters
wing, it had accelerated to the point where it had the energy of a man
swinging a 100 lbs sledge hammer.
snip

Did it happen in February?

On Sun, 16 Jan 2005 12:11:39 -0600, Pat Flannery wrote:



Craig Fink wrote:

The Reinforced Carbon Carbon (RCC) leading edge is essentially a high
strength charcoal that can withstand the extreme temperatures of entry.

Wouldn't "graphite" be a better discription? The only winged spacecraft
I can think of that had a charcoal leading edge during reentry was that
second German A4b with the wooden wings.



I would think more like a composite. The graphite is the high strength
part, but the graphite fibers are glued together with carbon (essentially
charcoal). Kind of like fiberglass/epoxy composite, except instead of
fiber glass it has fiber graphite, and instead of epoxy it has carbon to
hold it all together.

Craig Fink

On Sun, 16 Jan 2005 14:09:03 -0600, IDAK wrote:

On Sun, 16 Jan 2005 15:10:06 GMT, in sci.space.history, Craig Fink
wrote:

Two years ago today on January 16, 2003, a piece of foam accidentally
ripped loose from the External tank. Tumbling into the supersonic
slipstream between the External Tank and Orbiter, the wedge shaped piece
of foam flew and accelerated into the Orbiter's wing. In the short time
that it took to travel between the External Tank and impact the Orbiters
wing, it had accelerated to the point where it had the energy of a man
swinging a 100 lbs sledge hammer.
snip

Did it happen in February?

That's the Columbia Disaster your talking about, that's February 1st. The
Accident occurred two years ago today, the Disaster occurred 16 days after
that because nobody did anything about the Accident.

Craig Fink

Craig Fink wrote:

:On Sun, 16 Jan 2005 12:11:39 -0600, Pat Flannery wrote:
:
: Craig Fink wrote:
:
:The Reinforced Carbon Carbon (RCC) leading edge is essentially a high
:strength charcoal that can withstand the extreme temperatures of entry.
:
: Wouldn't "graphite" be a better discription? The only winged spacecraft
: I can think of that had a charcoal leading edge during reentry was that
: second German A4b with the wooden wings.
:
:I would think more like a composite. The graphite is the high strength
art, but the graphite fibers are glued together with carbon (essentially
:charcoal). Kind of like fiberglass/epoxy composite, except instead of
:fiber glass it has fiber graphite, and instead of epoxy it has carbon to
:hold it all together.

Uh, graphite IS carbon....

On Sun, 16 Jan 2005 22:42:43 GMT, Fred J. McCall
wrote:

Uh, graphite IS carbon....

....True, but probably less accurate than just using carbon fiber
instead of graphite.
OM

--

"No ******* ever won a war by dying for | http://www.io.com/~o_m
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- General George S. Patton, Jr

OM wrote:

On Sun, 16 Jan 2005 22:42:43 GMT, Fred J. McCall
wrote:



Uh, graphite IS carbon....



...True, but probably less accurate than just using carbon fiber
instead of graphite.



Yeah- but "charcoal"? You're going to reenter the atmosphere with wing
leading edges made out of a combustible substance?

Pat

Pat Flannery wrote:
OM wrote:
...True, but probably less accurate than just using carbon fiber
instead of graphite.

Yeah- but "charcoal"? You're going to reenter the atmosphere with wing
leading edges made out of a combustible substance?

As opposed to ... Aluminum? Think about it.

Christopher M. Jones wrote:


As opposed to ... Aluminum? Think about it.


How about this one: pencils cores are made of of carbon graphite, but we
call it a "lead"...so if the Shuttle's leading edges are said to be made
out of carbon graphite...maybe we should make them out of.... ;-)
Seriously, the Chinese made the heat shields on their recon sats out of
oak IIRC (I don't know if they still do) but the idea is that it starts
out as wood and turns into charcoal on the way down. I don't know what
happens if it starts out as charcoal- but I suspect that mesquite plays
some vital part in this design concept.... :-\

Pat