Subject: [ids.analysis.forum] Final Orbit Trim Maneuver on Feb 14 Places Jason-1 in Interleaved Orbit
From: "Lemoine, Frank G. (GSFC-698.0)" <[email-masked]>
To: <[email-masked]>
Cc: <[email-masked]>
Date: Mon, 16 Feb 2009 09:21:25 -0600

Dear Colleagues-

JPL has announced that Jason-1 has concluded the series
 of orbit change maneuvers that were initiated 2.5 weeks ago.
The last of the orbit change maneuvers (as detailed below)
occurred on February 14, 2009.

Jason-1 is now located in an interleaved orbit with respect to
the Jason-2 spacecraft. The altimeter was reactivated on February
10, 2009, and apart from a brief incident with a star tracker that was 
apparently the result of a single event upset, all systems are nominal.

DORIS analysts are cautioned that the South Atlantic Anomaly
(SAA) DORIS Correction Model is optimized for Jason-1 in
its original (TOPEX) ground track, and that further work 
is underway by J.M. Lemoine (CNES)  and H. Capdeville (CLS)
to optimize the model for the new orbit configuration.

Best regards,
Frank Lemoine
Code 698, Planetary Geodynamics Laboratory

===================================
===================================
Fifth and Final Jason-1 Orbit Change Maneuver Results:

1st burn:  2009/02/14 at 18:01:49 UTC
2nd burn:  2009/02/14 at 20:45:20 UTC
Observed delta-SMA = +480 m  (+500m targeted);  Efficiency: 96%.

This placed Jason-1 well within the new station-keeping control box (+/- 1 km) on 
14 February 2009 at 20:51 UTC.

A routine station-keeping maneuver is planned for 19 February 2009, to center Jason-1 
within the control box prior to the start of Science Cycle 263.

Thank you for your excellent support in these last three weeks!

Very best regards.
--
Glenn M. Shirtliffe
Jason-1 Project Manager
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