GSSAP pre-launch elements for 2014 Jul 26 UTC

From: Ted Molczan via Seesat-l <seesat-l_at_satobs.org>
Date: Fri, 25 Jul 2014 19:34:46 -0400
Two Geosynchronous Space Situational Awareness Program (GSSAP) satellites are scheduled for launch from CCAFS on a Delta
4 Medium+ 4,2 rocket, on 2014 Jul 26, at 22:51 UTC.

Also aboard is the Automated Navigation and Guidance Experiment for Local Space (ANGELS) satellite.

http://www.spaceflightnow.com/delta/d368/status.html

The following elements are based on launch at the above time.

LEO coast                                                258 X 272 km
1 70501U          14207.96956021  .00000000  00000-0  00000-0 0    08
2 70501  27.2800 105.2952 0010000 183.0000 359.3500 16.05000000    08
 
GTO burn at 1st descending node                        278 X 36398 km
1 70502U          14207.96982632  .00000000  00000-0  00000-0 0    06
2 70502  27.2794 105.2897 7307042 182.7762   0.0513  2.23480002    05
 
GTO burn at 1st ascending node                         278 X 36398 km
1 70503U          14208.00024726  .00000000  00000-0  00000-0 0    04
2 70503  27.2800 105.0552 7307000   3.4000 359.6000  2.23480000    00

The above are realistic, but not based on any detailed knowledge of the planned launch, intended only as a rough guide.

My guess is that the payload orbits will be inclined at least several degrees.

Most GEO launches from CCAFS perform their GTO burn at the first descending node, about 25 min. after launch. They reach
GEO altitude about 5 h after launch, near 96 E. Some GTO burns occur at the first ascending node, about 69 min. after
launch; GEO altitude is reached about 6 h after launch, near 93 W.

If GSSAP's GTO burn occurs at the first ascending node, then the fuel dump of the Delta 2nd stage may be visible to
western hemisphere observers, appearing like a bright comet. Based on an old Delta IV payload planning guide, about 6
min after the GEO circularization manoeuvre, the now separated 2nd stage would perform the CCAM (contamination and
collision avoidance manoeuvre), followed ~6 min. later by the fuel dump. On the GSSAP launch, that would occur sometime
after roughly T+5h59m (more likely later than earlier).

I have no idea whether GSSAP will burn to GTO at the first ascending node, so it probably is not worth staying up past
midnight to see a fuel dump based on my speculation. For anyone intending to do so anyway, the relevant TLE is 70503.
Best to observe with the unaided eye, or binoculars with a wide FOV.

Happy hunting!
Ted Molczan


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Received on Fri Jul 25 2014 - 18:36:18 UTC

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