[meteorite-list] Re: Debris Found In Joshua Tree May Be From Columbia

From: Ron Baalke <baalke_at_meteoritecentral.com>
Date: Thu Apr 22 10:18:25 2004
Message-ID: <200302071821.KAA13822_at_zagami.jpl.nasa.gov>

I wrote:
>> OK, let's assume then that the debris took a slight deviation
>> from the shuttle's flight path towards the south when it separated
>> from the shuttle. Could that be enough to account for the
>> additional distance to Joshua Tree?

Rob responds:
>The altitude was about 61 km over north central Texas, so it
>was still pretty high. A 230-mile cross-track spread in debris
>might seem like a lot, but given that the main break-up was
>beginning at least 600 miles to the west-northwest (and initial
>pieces were separating at least 1500 miles to the WNW), a
>downstream spread of +/- 115 miles represents a dispersion
>of +/- 11 degrees for the main breakup,

I concur, I calculate a dispersion angle of +/- 10.8 degrees.

>By contrast, the necessary angular diversion
>for a fragment breaking off at 8:53am EST (while Columbia was
>just off the coast of California) is over 30 (!) degrees to
>Joshua Tree, CA.

True. Let's assume then that the debris separated over the Pacific.
I calculate with a 11 degree dispersion angle, the separation would
have to occur about 1,400 miles to the west of Joshua Tree.

>What this means is that the only way to get debris to Joshua
>Tree is if it separates from Columbia well before it reaches
>the California coastline -- at least two or three minutes
>earlier (8:51, 8:50). But this is a problem, because the
>further you go back in time, the higher the Shuttle is, and
>the thinner the atmosphere. So the possible deviation from
>a purely ballistic trajectory is lower.

Duly noted. OK, so was the shuttle doing anything of significance
around this time? It turns out it was! The shuttle had just
performed its first S-bank maneuver:
 
- 8:49 am: Columbia begins a series of gentle side-to-side turns designed
 to lower its speed. The first of these is to the right.

Note the bank was to the right. If any debris were to fall
off during the bank turn, it would tend to be thrown off in a
southwards direction from the flight path. And Joshua Tree is
south of the shuttle's flight path. I really don't think
Joshua Tree can be ruled out for possible shuttle debris.
Since we now know the shuttle's left wing was damaged with a
jagged edge, I think there good possibility that the metallic
object found in Joshua Tree is a piece of the left wing.

Any comments?

Ron Baalke
Received on Fri 07 Feb 2003 01:20:59 PM PST