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Rise or Fall


Tyneside, UK
2014 Dec 18
Thursday, Day 352

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Phobos-Grunt - Reentry Watch

Re-entry occurred as anticipated 2012 January 15 and Phobos-Grunt was destroyed by the heat of friction with air molecules.


Re-entry Estimates

As the end approached, estimates homed in on a likely re-entry time but still covered several hours and, eventually, several tens of minutes. The final few days' estimates are listed here.

Re-entry Estimates - all dates/times are UTC
2012 Jan 16, 07:00 ± 36 hrs
Issued 2012 Jan 9, 03:48
Seesat-L (Ted Molczan)
2012 Jan 15, 11:10 ± 10 hrs
Issued 2012 Jan 9, 16:00
Seesat-l (Harro Zimmer)
2012 Jan 16, 07:00 ± 32 hrs
Issued 2012 Jan 10, 06:34
Seesat-L (Ted Molczan)
2012 Jan 16, 08:30 ± 36 hrs
Issued 2012 Jan 10, 09:23
Aerospace CORDS
2012 Jan 15, 14:36 ± 72 hrs
Issued 2012 Jan 10, 21:20
Spacetrack (TIP)
2012 Jan 16, 18:00 ± 24 hrs
Issued 2012 Jan 11, 04:21
Seesat-L (Ted Molczan)
2012 Jan 15, 09:18
Issued 2012 Jan 11, 06:00
Roscosmos - approximate epoch
2012 Jan 16, 02:36 ± 18 hrs
Issued 2012 Jan 11, 08:52
Aerospace CORDS
2012 Jan 15
Issued 2012 Jan 11
Spacetrack (60 day)
2012 Jan 15, 12:12
Issued 2012 Jan 12, 06:00
Roscosmos - approximate epoch
2012 Jan 15, 17:57 ± 20 hrs
Issued 2012 Jan 12, 08:20
Aerospace CORDS
2012 Jan 15, 12:00 ± 3 hrs
Issued 2012 Jan 12, 17:00
Seesat-L (Harro Zimmer)
2012 Jan 15, 17:09 ± 14.5 hrs
Issued 2012 Jan 12, 18:36
Spacetrack (TIP)
2012 Jan 15, 17:52 ± 504 min
Issued 2012 Jan 13, 10:40
Aerospace CORDS
2012 Jan 15, 17:05 ± 3 hrs
Issued 2012 Jan 13, 11:30
Seesat-L (Harro Zimmer)
2012 Jan 15, 16:22
Issued 2012 Jan 13
Roscosmos
2012 Jan 15, 18:01 ± 526 min
Issued 2012 Jan 13, 15:30
Spacetrack (TIP) - incorrect epoch?
2012 Jan 15, 17:34 ± 9 hrs
Issued 2012 Jan 13, 15:30
Spacetrack (TIP)
2012 Jan 15, 22:16 ± 9 hrs
Issued 2012 Jan 14, 08:35
Aerospace CORDS
2012 Jan 15, 18:44 ± 6 hrs
Issued 2012 Jan 14, 18:00
ESA Space Situation Awareness Group
2012 Jan 15, 18:30 ± 234 min
Issued 2012 Jan 14, 18:00
Roscosmos - approximate epoch
2012 Jan 15, 17:22 ± 90 min
Issued 2012 Jan 14, 19:40
Seesat-L (Harro Zimmer)
2012 Jan 15, 18:14 ± 288 min
Issued 2012 Jan 14, 20:30
Spacetrack (TIP)
2012 Jan 15, 17:16 ± 204 min
Issued 2012 Jan 14, 20:30
Spacetrack (TIP) - incorrect epoch?
2012 Jan 15, 18:53 ± 72 min
Issued 2012 Jan 15, 06:00
Roscosmos - approximate epoch
2012 Jan 15, 19:21 ± 3 hrs
Issued 2012 Jan 15, 06:25
Aerospace CORDS
2012 Jan 15, 17:49 ± 45 min
Issued 2012 Jan 15, 07:10
Seesat-L (Harro Zimmer)
2012 Jan 15, 18:02 ± 24 min
Issued 2012 Jan 15, 14:00
Seesat-L (Harro Zimmer)
2012 Jan 15, 17:23 ± 24 min
Issued 2012 Jan 15, 15:30
Spacetrack (TIP)
2012 Jan 15, 17:52 ± 19 min
Issued 2012 Jan 15, 16:36
Aerospace CORDS
2012 Jan 15, 18:12 ± 22 min
Issued 2012 Jan 15, 17:00
Roscosmos - approximate epoch
2012 Jan 15, 17:46 ± 1 min
Issued 2012 Jan 15, 17:53
Spacetrack (TIP Final Report)

Spacetrack issued a message January 15 at 20:34 UTC and stated simply that it had decayed within the forecast period of 16:59-17:47 UTC. Then, on Jan 17 a Final TIP Message in full, standard format appeared, giving the location - it was shown as being issued Jan 15 at 17:53 UTC.

The final Phobos-Grunt orbit data is here.

There is a map showing the final ground trace here.


A Different Way of Looking At It

Here is the same information presented graphically but going back to December 1. Through December, estimates were drifting later with time suggesting that Phobos-Grunt may not have been following a natural pattern. Maybe there was still a degree of thruster operation occurring, acting against atmospheric drag. Alternatively, if it was still orienting itself towards the Sun, then the aspect that Phobos-Grunt presented to the direction of travel will have been changing as the orbit changed its angle to the Earth-Sun line. Around the turn of the year, the time drift ceased.

NOTE - the spread in estimated dates and times up to about Jan 12 was partly due to differing models being used by different sources, and partly to changes in forecasts for the 'Solar Weather' affecting upper atmosphere density. Change necessitated having to revisit the reentry estimate.

Phobos-Grunt Reentry Estimates


Charts on this page are produced using JpGraph.

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Reproduction in whole or in part without permission is prohibited