Re: which is which? (Dragon objects)

From: C. Bassa via Seesat-l <seesat-l_at_satobs.org>
Date: Wed, 15 Apr 2015 13:26:34 +0200
To do a more quantitative analysis I've taken the 40590 JSpOC elset
and computed new elsets after adding small velocity changes at the
appropriate times for space craft separation and the solar array
deploy. Separation took place at 20:21:00 UT (00:10:07 after launch),
and the deploy at 20:23:29UT (00:12:36 after launch). See
https://www.youtube.com/watch?v=csVpa25iqH0 for a video.

The 40590 elset was propagated to 20:21:00UT, giving the 80001 elset,
and then 1 m/s velocity was added in the prograde direction to give
elset 80002. Next, the 80002 elset was propagated to 20:23:29UT, and
then 5 m/s was added in the normal and anti-normal directions, giving
the 80003 and 80004 elsets.

At the time of your image, this is how the objects would appear from
your location: https://dl.dropboxusercontent.com/u/52579487/20150414_crs6_dv.png

Note that the added velocities are guesses, and the prograde and
normal/anti-normal directions are approximate based on the video.
However, they show that the identification of the objects is correct.
The two faint objects to the side are the solar array covers, the
trailing object is the upper stage.

Regards,
   Cees

1 80001U 15999A   15104.84791667  .00000000  00000-0  00000-0 0    04
2 80001  51.6681  40.9562 0113359  47.6113 -353.3713 15.97436393    04
# 40590 + 0 m/s prograde
1 80002U 15999A   15104.84791667  .00000000  00000-0  00000-0 0    05
2 80002  51.6681  40.9562 0115927  47.7616 -353.5216 15.96809768    06
# 40590 + 1 m/s prograde
1 80003U 15999A   15104.84964120  .00000000  00000-0  00000-0 0    02
2 80003  51.6839  40.9891 0115936  47.7399  16.3949 15.96808720    08
# 80002 + 5 m/s normal
1 80004U 15999A   15104.84964120  .00000000  00000-0  00000-0 0    03
2 80004  51.6524  40.9049 0115926  47.7982  16.3888 15.96808884    05
# 80002 + -5 m/s normal
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Received on Wed Apr 15 2015 - 06:27:22 UTC

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