R: OTV-4 recovered by Jose Luis Ruiz

From: alberto rango via Seesat-l <seesat-l_at_satobs.org>
Date: Sun, 12 Feb 2017 11:07:12 +0100
Hi Jon,

 

many thanks  for your OTV 4 elset.

Unfortunately  the sky was overcastted this Sunday morning at Bari (4641).

Besides, the OTV 4 visibility period is going to end next Tuesday 14th.

Regards,

 

Alberto

 

Da: Jon . [mailto:jonmikelk_at_gmail.com] 
Inviato: sabato 11 febbraio 2017 11.43
A: Seesat List; alberto rango; José Luis Ruiz
Oggetto: OTV-4 recovered by Jose Luis Ruiz

 

Hello all,

Yesterday José sent three photos of an UNID satellite. As Alberto confirmed, this object is OTV-4, running about 54 minutes early on a 26 day old elset, pointing to a maneuver.

Here are the manually reduced data:

40651 15 025A   3602 B 20170210054757000 18 15 1713087+561103 38 S
40651 15 025A   3602 B 20170210054815000 18 15 1849273+461326 38 S
40651 15 025A   3602 B 20170210054823000 18 15 1908540+423838 38 S
40651 15 025A   3602 B 20170210054840000 18 15 1944464+342852 38 S

3602= 36.839, -2.4498, 30m

The points are aproximate, as it's not clear when the trail starts/ends and because the images are moved.

 

Fitting those four points yelds the following approximate orbit:

OTV-4                                                    307 X 320 km
1 40651U 15025A   17041.22658390 0.00013452  00000-0  50000-4 0    04
2 40651  37.9882 141.2956 0009360 283.0071  76.9672 15.86867551    01
rms 0.40

Of course it's not possible to determine the mean motion with only one arc, so I invite to the rest of observers to try other solutions.

Recently, some rumours appeared that OTV-4 could land in the next few days: 

https://twitter.com/NASASpaceflight/status/829313151762051073

Chris (writer of nasaspaceflight.com) pointed that there are some landing operations running at Shuttle Landing Facility and Orbiter Processing Facility-1 on Kennedy Space Center the february 8th.

 

Using José's data, and the Mike's latest elset, the maneuver date yelds the 5 of february. Of course this is an aproximation due to the big mean motion uncertainty of the new search elset.



There are no NOTAMs published for this landing yet. Using the above elset the landing opportunities on KSC are the following:

(Date/times on UTC)

  Date     Time     Node

Feb. 11    14:04    Desc *

Feb. 11    07:49    Asc  **

Feb. 12    13:44    Desc 

Feb. 12    07:15    Asc  

Feb. 13    13:12    Desc 

Feb. 13    06:41    Asc  **

Feb. 14    12:48    Desc 

Feb. 14    06:10    Asc  

Feb. 15    12:13    Desc

Feb. 15    05:25    Asc

Dates with one star are probable, and with two stars are the most ideal ones. The rest are not probable, discarded by large MA-RAAN-Landing site mismatch. Only ascending node opportunities are marked with two stars because if the spacecraft lands in descending node it would have to cross the sourthem U.S. during the reentry.

Note that the accuracy of those times is low as we don't have an accurate orbit. 

I will publish improved predictions if any observation data becomes available. Note that ideal landing opportunities can change.



Jon.


-- 

Jon, COSPAR 6242, 42.9453, -2.82839, 623m, Bitoriano, Basque Country.

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Received on Sun Feb 12 2017 - 04:08:04 UTC

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