ZUMA search elset estimates

From: Marco Langbroek via Seesat-l <seesat-l_at_satobs.org>
Date: Tue, 2 Jan 2018 18:25:21 +0100
Hi all,

First, a happy, healthy and clear 2018!

The classified Falcon 9 launch of ZUMA by SpaceX, postponed from last November,
is now slated for January 5 (January 4 in local time) between 1:00 UT and 3:30
UT. It will launch from pad 40 of Kennedy Space Center, Florida.

Launch and de-orbit hazard zones from Maritime Broadcast Warnings are similar to
those in November.

The launch window (00:55-03:37 UT, Jan 5) is the same as in November too, i.e.
it has not shifted indicating no particular orbital plane is targetted.

This would seem to EXCLUDE that ZUMA targets the orbital plane of the ISS or USA
276, as hypothesized in November.

The orbital plane of the ISS passes over the launch site at ~7:30 UT, which is
well after the end of the launch window. The orbital plane of USA 276 passes
over the launch site at ~5:00 UT, again well after the end of the launch window.

The launch would have to be postponed again, by 10 days, to move the ISS orbital
plane crossing moment into the launch window. The Area Broadcast Warnings are
valid to January 18.



The following elsets are based on Ted Molczan's original estimates from November
2017 (http://www.satobs.org/seesat/Nov-2017/0055.html), adjusted for the  shift
in launch date, and launch date 5 January 2018.

I give elsets for launch times in 30-minute intervals over the launch window, 5
January 01:00 - 03:30 UT:


ZUMA 1:00 UT
1 70000U 18999A   18005.04166668  .00011340  00000-0  15763-3 0    01
2 70000  50.0032 013.0780 0015627 353.6173  21.6500 15.55612078    01

ZUMA 1:30 UT
1 70001U 18999A   18005.06250001  .00011340  00000-0  15763-3 0    09
2 70001  50.0032 020.5985 0015627 353.6173  21.6500 15.55612078    02

ZUMA 2:00 UT
1 70002U 18999A   18005.08333335  .00011340  00000-0  15763-3 0    04
2 70002  50.0032 028.1190 0015627 353.6173  21.6500 15.55612078    05

ZUMA 2:30 UT
1 70003U 18999A   18005.10416668  .00011340  00000-0  15763-3 0    09
2 70003  50.0032 035.6396 0015627 353.6173  21.6500 15.55612078    07

ZUMA 3:00 UT
1 70004U 18999A   18005.12500001  .00011340  00000-0  15763-3 0    07
2 70004  50.0032 043.1601 0015627 353.6173  21.6500 15.55612078    01

ZUMA 3:30 UT
1 70005U 18999A   18005.14583335  .00011340  00000-0  15763-3 0    01
2 70005  50.0032 050.6806 0015627 353.6173  21.6500 15.55612078    02


Alternatively, here is a set of elset estimates I constructed from the launch
azimuth and an estimate of the orbit insertion point and time (assumed insert in
perigee), for an assumed 395 x 405 km orbit:

ZUMA 01:00 UT
1 70006U 18999A   18005.04166667  .00000000  00000-0  00000-0 0    02
2 70006 049.9999 013.6127 0007377 049.0376 324.6717 15.55741113    00

ZUMA 01:30 UT
1 70007U 18999A   18005.06250000  .00000000  00000-0  00000-0 0    00
2 70007 049.9999 021.1332 0007377 049.0376 324.6717 15.55741113    03

ZUMA 02:00 UT
1 70008U 18999A   18005.08333333  .00000000  00000-0  00000-0 0    04
2 70008 049.9999 028.6538 0007377 049.0376 324.6717 15.55741113    04

ZUMA 02:30 UT
1 70009U 18999A   18005.10416667  .00000000  00000-0  00000-0 0    00
2 70009 049.9999 036.1743 0007377 049.0376 324.6717 15.55741113    07

ZUMA 03:00 UT
1 70010U 18999A   18005.12500000  .00000000  00000-0  00000-0 0    09
2 70010 049.9999 043.6948 0007377 049.0376 324.6717 15.55741113    09

ZUMA 03:30 UT
1 70011U 18999A   18005.14583333  .00000000  00000-0  00000-0 0    02
2 70011 049.9999 051.2154 0007377 049.0376 324.6717 15.55741113    04


Allow for several minutes offset in pass time and several degrees in cross-track
error.

If the launch is at the start of the launch window, there are almost no sighting
opportunities on the first revolution.

If the launch is at the end of the launch window, there could be sighting
opportunities from the Balkans and Near East 30 minutes after launch.

Europe in general will get sighting opportunities only half a month after
launch, if these estimated elsets are anywhere near reality.

- Marco


-----
Dr Marco Langbroek  -  SatTrackCam Leiden, the Netherlands.
e-mail: sattrackcam_at_langbroek.org

Cospar 4353 (Leiden):     52.15412 N, 4.49081 E (WGS84), +0 m ASL
Cospar 4355 (Cronesteyn): 52.13878 N, 4.49937 E (WGS84), -2 m ASL
Station (b)log: http://sattrackcam.blogspot.com
Twitter: _at_Marco_Langbroek
-----
_______________________________________________
Seesat-l mailing list
http://mailman.satobs.org/mailman/listinfo/seesat-l
Received on Tue Jan 02 2018 - 11:26:13 UTC

This archive was generated by hypermail 2.3.0 : Tue Jan 02 2018 - 17:26:13 UTC