Atlas V 401/GPS IIF-10 and Ariane 5 ECA/Star One C4 & MSG-4 launch orbit estimations

From: Jon . via Seesat-l <>
Date: Tue, 14 Jul 2015 12:15:58 +0200

An Atlas V 401 is scheduled to launch the GPS IIF-10 satellite the
2015/07/15 at 15:36 UTC.

The flight azimuth will be north-east at about 45.8 degrees.
Shortly after launch the vehicle will start the pitch-roll maneuvers for
take direction of northerm UK (sadly its day at this moment in Europe). The
Main Engine Cut-Off 1 will be at T+1022.2 seconds, at 15:53:02.2 UTC, when
the rocket is on MTO transfer orbit. This is MTO transfer orbit estimation,
that would be valid at MECO-1 till MES-2 (Main Engine Start-2), 3 hours and
17 minutes after launch:

GPS IIF-10 #0                                          222 X 20356 km
1 71000U 15600A   15196.65695602 0.00000000  00000-0  00000+0 0    03
2 71000  54.9954  66.0379 6039771  92.2703 348.9227  4.03447725    04

Once done this maneuver, of about 2000 m/s since the rocket enters orbit,
it will pass over UK, eastern Europe and western Asia, Arabia, and finally
the pacific ocean in ballistic trajectory till reach the southerm
australian sea (see the mission ground-track on the press kit), when a
final burn will be made for circularize the orbit and deploy the GPS
satellite near the operational slot. This TLE should start working at
T+03:23:14.6 after launch, at 20:59:14.6 UTC. I've put the epoch just at
this time:

GPS IIF-10 #1                                        20463 X 20479 km
1 71001U 15601A   15196.79113426 0.00000000  00000-0  00000+0 0    08
2 71001  55.0078  67.9128 0002904 242.8547  30.0007  1.97330111    02

Once the satellite is deployed the USPACECOM will need about half day or so
to publish the first official TLE, so my guess is to mantain this #1 orbit
since 20:59:14 UTC till the USPACECOM publishes its first orbit. Once
published my guess is to replace my TLE.

Note: At ~20:42 UTC till ~20:43:30 UTC the MES-2 (Main Engine Start-2) will
be made, that will be easily visible in sourthem Australia. Also, after
spacecraft separation the Centaur upper stage may make its tipical
fuel-venting and (maybe????) CCAVM (Collision and Contamination Avoidance
Maneuver), making a nice comet-form bright cloud on the sky, usually
confused as an UFO. I can't see the NOTAM for Centaur de-orbit so I doubt
the Centaur will be de-orbited after SC separation.


Some hours later, an Ariane 5 ECA rocket is scheduled to launch the Star
One C4 & MSG-4 satellites the 2015/07/15 at 21:42 UTC to GTO orbit. Target
is 249 x 35904 Km, 4 degree inclination orbit.

Press kit:

Here is the orbit estimation for Ariane 5 ECA/Star One C4&MSG-4 satellites:

Ariane 5 ECA #0         13.0  2.5  0.0  3.0 d   17     231 X 35494 km
1 70000U 15500A   15196.91042824 0.00000000  00000-0  00000+0 0    02
2 70000   4.0007  88.0982 7273455 175.8108 354.3572  2.30104411    03

The numbers at half of line zero is a very rough brightnest curve
estimation in mcnames format.

This data will be uploaded to and, I will post
links later or tomorrow.

Be good!!

P.S: As allways those TLEs are valid only if launch occurs at planned time,
at launch window open. Probably I will not be available to update them if a
delay occurs.


Jon, COSPAR 6242, 42.9453, -2.82839, 623m, Bitoriano, Basque Country.
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Received on Tue Jul 14 2015 - 05:16:40 UTC

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