RE: Re-entry of Soyuz TMA-19M rocket body seen from Newfoundland and Labrador

From: Ted Molczan via Seesat-l <seesat-l_at_satobs.org>
Date: Fri, 18 Dec 2015 15:23:48 -0500
Below is a plot of the ground track relative the sighting locations known to me:

http://www.satobs.org/reentry/2015-076B/2015-076B_re-entry_ground_track.jpg

The motion was from west to east. The ground track spans the portion of the descent from 90 km to my estimate of the
point of theoretical impact, near 50.56 N, 41.77 W. 

The alternating red and white segments span 5 s of flight. Their progressively shorter length is due to the loss of
horizontal velocity due to atmospheric drag. 

By the time any surviving fragments reached about 30 km altitude, they would have had nearly zero horizontal velocity,
resulting in a nearly vertical drop into the Atlantic Ocean, about 1000 km south of Greenland. By then, they would have
ceased to be incandescent, so that portion of the descent would not have been visible. Fragments of lower areal density
would have fallen well to the west of the theoretical impact. I am not aware of any reports of suspected debris
discoveries.

The following kmz file contains the data used to generated the above graphic. It also includes a 3D trajectory, which
enables viewing the path of the trajectory through the sky, using Google Earth ground-level view.

http://www.satobs.org/reentry/2015-076B/2015-076B_re-entry.kmz

For example, below is the initial portion of the trajectory as seen from Glenwood, NL:

http://www.satobs.org/reentry/2015-076B/2015-076B_re-entry_Glenwood.jpg

Upon loading the kml into G.E., only the 2D trajectory is enabled. The 3D has been disabled, to avoid confusion due to
parallax when viewed from overhead. To enable 3D, simply click the check box beside it in G.E. To plot the 3D trajectory
from a location of interest, drop down into Street view, then click the Ground-level view button immediately to its
right. Clicking on a line segment opens a window showing the time (UTC) and estimated altitude. I believe the altitude
is accurate to +/- 5 km.

Below, I have used the kmz file to illustrate the vertical profile of the descent. The aforementioned final vertical
drop is clearly evident at far right.

http://www.satobs.org/reentry/2015-076B/2015-076B_re-entry_verical_profile.jpg

I estimated the trajectory by propagating USSTRATCOM's final TLE, using the numerical integrator in GMAT 2014a (General
Mission Analysis Tool). TLE Analyzer 2.12 was used to convert the TLE to one of the orbital models supported by GMAT.
The GMAT script is available here:

http://www.satobs.org/reentry/2015-076B/2015-076B_v1.script

Ted Molczan


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Received on Fri Dec 18 2015 - 14:24:45 UTC

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