[Isocops] IBEX Orbit# 199 ATS (9 Mar 13 - 19 Mar 13)

[fair-play at comcast.net]

Nigel, 


I'll take a shot at it. The command generation software uses the current ephemeris to determine the 14 Re crossing point: 



ibex_orbit -r 199 -D 14 -R E 
0199 
2013/03:10:06:56:17 2013/03:18:16:45:58 


The maneuver window opens at 14 Re + 0.5 hour and the software assumes that the maneuver will occur when the window opens. If you do the math, you'll come up with 


2013/03:18:16:15:58 


The command generation software has a built-in 2 second delay that it adds to each command so the time for the transition to housekeeping in the STF/ATS is 


2013/03:18:16:16:00 


MPS uses the times that were created in the forecast STF for its time determinations. Times often shift somewhere between 1 and 2 minutes with each ephemeris update so as the month wears on the differences between the times in the current ephemeris and the forecast files grows larger and we can see situations like the one you noticed. We've seen this before and as far as I know it isn't a problem. 


Ken 
----- Original Message -----
From: "Nigel Angold" <ngangold at earthlink.net> 
To: "Ibex Mission Operations" <ibexops at gmail.com> 
Cc: "Thomas Regiec" <regiec.thomas at orbital.com>, "IBEX-FDG" <IBEX.fdg at applieddefense.com>, "ISOC at New Hampshire" <isocops at lists.sr.unh.edu>, "Bret Hautamaki" <hautamaki.bret at orbital.com>, "John Cavallo" <cavallo.john at orbital.com>, "Tim Perry" <perry.tim at orbital.com>, "Robert Lockwood" <Lockwood.Robert at orbital.com>, "Ryan Tyler" <tyler.ryan at orbital.com>, "Walker Cross" <Cross.Walker at orbital.com>, "Sheral Wesley" <wesley.sheral at orbital.com>, "IBEXOPS/ORB" <IBEXops at orbital.com> 
Sent: Tuesday, February 26, 2013 5:36:46 PM 
Subject: Re: [Isocops] IBEX Orbit# 199 ATS (9 Mar 13 - 19 Mar 13) 

For the orbit 199 perigee maneuver, can anyone explain why the Housekeeping command is after the Cat Bed Heater on command? 


Does it matter? 


The housekeeping command is 30min before 14 Re and the maneuver enable is 24min 41s after 14 Re. The CBH on is the usual 55min before maneuver enable. 


Nigel 



@ECT_SetHTRCmd CATBED_5N_HTR,ON $TIME=2013/03:18:16:15:40 
@FCT_SetScState housekeeping $TIME=2013/03:18:16:16:00 
@ACT_SetKFInputSelect GND_CMD, 0, 0, 0, 0 $TIME=2013/03:18:17:00:40 
@ACT_SetEstUpdateEnables ENABLE, DISABLE $TIME=2013/03:18:17:00:41 
@FCT_SetFcMode burn $TIME=2013/03:18:17:07:40 
@ACT_SetInrDir 0.997648,-0.058205,-0.03619 $TIME=2013/03:18:17:08:40 
@ACT_SetLrTarget ACS_INERTIAL $TIME=2013/03:18:17:09:40 
@ACT_SetThrustTime 660 $TIME=2013/03:18:17:10:35 
@ACT_SetThrustEnable ENABLE $TIME=2013/03:18:17:10:40 
@ACT_SetThrustEnable DISABLE $TIME=2013/03:18:17:20:40 
@ECT_SetHTRCmd CATBED_5N_HTR,OFF $TIME=2013/03:18:17:20:41 
@ACT_SetThrustTime 0 $TIME=2013/03:18:17:21:10 
@ACT_SetStaticZrate ESTIMATOR, 0.418 $TIME=2013/03:18:17:35:50 
@ACT_SetKFInputSelect STA_PCT_VALID, 48,18,23,53 $TIME=2013/03:18:17:36:00 
@FCT_SetFcMode Mission $TIME=2013/03:18:17:36:40 




Guys, 
Here are the planning files and ATS for Orbit# 199 
Please respond to this email thread with all approvals and questions. 
Approvals and questions are required before 27 Feb 13 @1800 UTC 

Note the following: 
1. There are NO Battery Balancing Commands this orbit 
2. APL-18 SSR_Dump contact on 18 Mar 13 @1900 UTC 
3. Command Load Constraint Violation Report (CCVR) 
========================== 
HARD CONSTRAINT VIOLATIONS 
========================== 
NO VIOLATIONS. 
========================== 
SOFT CONSTRAINT VIOLATIONS 
========================== 
NO VIOLATIONS. 
============== 
OTHER MESSAGES 
============== 
NO MESSAGES. 



-- 
Sheral R. Wesley 
SPVR., Satellite Operations 
IBEX Mission OPS 
(304) 279-6678 <IBEX_2013_068_o0199a_v001.txt> <IBEX_2013_068_o0199a_v001.ccvr> <IBEX_2013_068_o0199a_v001.oef> <IBEX_Orbit199Contacts.txt> 




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