NROL-35 pre-launch elements: 2014 Dec 13

From: Jon . via Seesat-l <seesat-l_at_satobs.org>
Date: Fri, 12 Dec 2014 12:01:22 +0100
Hi all;

As Ted said, an Atlas V 541 is scheduled to launch the 2014/12/13 _at_ 03:13
UTC from Vandemberg SLC3E, at 34.640172°, -120.589583 WGS84.

This analysis uses orbits computed by Ted Molczan on 2008 on the NROL-28
(USA-200). The accuracy of those elsets were verified by the observations
of Greg Roberts and Scott (Campbell?) that tracked NROL-28 for more than
six hours.

Here my updated analysis:

The first elset is void at T+14 min after liftoff, when the spacecraft and
the Centaur upper stage reaches orbit with a positive perigee height:

NROL-35 SECO1                                           192 X 2215 km
1 70004U 14504A   14347.14445602 0.00000000  00000-0  00000+0 0    02
2 70004  62.5000 207.6737 1333700 180.0001   2.1478 13.14740000    07

After that the Molniya orbit insertion should be made, about 38 min after
liftoff:

NROL-35 SECO2                                         1117 X 37641 km
1 70005U 14505A   14347.39792824 0.00000000  00000-0  00000+0 0    02
2 70005  62.4000 207.6377 7090000 266.5070 180.3826  2.10000000    01

Once that the Centaur separates the payload, it should made a CCAM
(Collision and Contamination Avoidance Maneuver).
The maneuver fits with Centaur reentry NOTAM making a negative delta-v at
4:58:31 UTC, giving a reentry site more or less on the middle of the NOTAM
at -48.74, 139.65:

CENTAUR DE-ORBIT 2                                    -147 X 33546 km
1 70006U 14506A   14347.20695602 0.00000000  00000-0  00000+0 0    00
2 70006  62.3991 207.6636 7300128 258.1237  41.7968  2.47618863    04

Hoewer a less-energetic burn could be made at apogee. That would not fit
with the reentry NOTAM. The cause is maybe the imposibility of make to
reenter the Centaur with a maneuver on the apogee, but did not verified
this.

Thanks again to Ted Molczan who advised me by private some days ago that my
first Centaur de-orbit elset was wrong.
Also Thanks to Bob Christy (zarya.info) who provided me information to make
this analysis.

Be good!



Jon.

-- 
Jon Mikel, COSPAR 6242, 42.9453, -2.82839, 623m, Bitoriano, Basque Country.
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Received on Fri Dec 12 2014 - 05:02:04 UTC

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