All,

Note: Angle at descending after apogee sun precession maneuver: 3.921 deg
          Angle at orbit 604 apogee after perigee sun precession maneuver: 4.873 deg

I have looked at the orbit 603 ATS,

IBEX_2023_090_o0603a_v002.scr,


and I approve.


The only constraint violations in


IBEX_2023_090_o0603a_v002.ccvr


are from the removal of the


ACT_SetSpinPulseProtectEnable Enable


commands (2) and the proximity of contacts; the violations are expected.

Ascending and descending command sequences are consistent with each other, 15 Re ascending, the apogee maneuver time and 15 Re descending as determined from the OEF,

IBEX_2023_090_o0603a_v002.oef,


and as verified with ibex_orbit.


There are two star tracker outages.  The first starts 1.5+ days before 15 Re descending and runs for 1.5- days.  The second starts about 1 hour before 15 Re descending and runs for 9 hours.  Some despinning may be required due to the first outage.

The ground station command sequences are correct and the timing and bit rates match those in the contacts file,

IBEX_Orbit603_Contacts_v2.txt,


for all contacts (2).


We are doing battery cell balancing and the balancing commands are correct and offset by enough time from other commands.


The inertial precession maneuver at perigee of orbit 602 leaves us pointing in safe directions for the orbit 603 arc A ascending and descending sequences:


ibex_rotate -o -u 0.990755,0.12778,0.045572 -w ibex-sun -t 2023/04:01:17:23:58

Quaternion    +0.000000,+0.000000,+0.000000,+0.000000

 points axis  +1.000000,+0.000000,+0.000000

 towards ECI  +0.990755,+0.127780,+0.045572

 which is     R.A.   +7.349 Decl.  +2.612

 missing      R.A.  +10.496 Decl.  +4.487 (ibex-sun)

 error is     R.A.   +3.147 Decl.  +1.875

 for a total  3.658 deg


ibex_rotate -o -u 0.990755,0.12778,0.045572 -w ibex-sun -t 2023/04:04:20:22:30

Quaternion    +0.000000,+0.000000,+0.000000,+0.000000

 points axis  +1.000000,+0.000000,+0.000000

 towards ECI  +0.990755,+0.127780,+0.045572

 which is     R.A.   +7.349 Decl.  +2.612

 missing      R.A.  +13.407 Decl.  +5.753 (ibex-sun)

 error is     R.A.   +6.058 Decl.  +3.141

 for a total  6.809 deg


The sun precession maneuver at apogee leaves us pointing in safe directions at the time of the maneuver and for arc B ascending and descending sequences:


ibex_rotate -o -r +13.476 -d +5.783 -w ibex-sun -t 2023/04:04:22:10:38

Quaternion    +0.000000,+0.000000,+0.000000,+0.000000

 points axis  +1.000000,+0.000000,+0.000000

 towards ECI  +0.967518,+0.231852,+0.100761

 which is     R.A.  +13.476 Decl.  +5.783

 missing      R.A.  +13.476 Decl.  +5.783 (ibex-sun)

 error is     R.A.   +0.000 Decl.  +0.000

 for a total  0.000 deg


ibex_rotate -o -r +13.476 -d +5.783 -w ibex-sun -t 2023/04:04:23:40:44

Quaternion    +0.000000,+0.000000,+0.000000,+0.000000

 points axis  +1.000000,+0.000000,+0.000000

 towards ECI  +0.967518,+0.231852,+0.100761

 which is     R.A.  +13.476 Decl.  +5.783

 missing      R.A.  +13.534 Decl.  +5.808 (ibex-sun)

 error is     R.A.   +0.058 Decl.  +0.025

 for a total  0.063 deg


ibex_rotate -o -r +13.476 -d +5.783 -w ibex-sun -t 2023/04:08:23:44:33

Quaternion    +0.000000,+0.000000,+0.000000,+0.000000

 points axis  +1.000000,+0.000000,+0.000000

 towards ECI  +0.967518,+0.231852,+0.100761

 which is     R.A.  +13.476 Decl.  +5.783

 missing      R.A.  +17.120 Decl.  +7.289 (ibex-sun)

 error is     R.A.   +3.644 Decl.  +1.506

 for a total  3.921 deg


The sun precession maneuver at perigee leaves us pointing in safe directions at the time of the maneuver at at orbit 604 apogee:


ibex_rotate -o -r +17.225 -d +7.327 -w ibex-sun -t 2023/04:09:02:38:57

Quaternion    +0.000000,+0.000000,+0.000000,+0.000000

 points axis  +1.000000,+0.000000,+0.000000

 towards ECI  +0.947350,+0.293707,+0.127532

 which is     R.A.  +17.225 Decl.  +7.327

 missing      R.A.  +17.225 Decl.  +7.327 (ibex-sun)

 error is     R.A.   +0.000 Decl.  +0.000

 for a total  0.000 deg


ibex_rotate -o -r +17.225 -d +7.327 -w ibex-sun -t 2023-04-13T23:59:46.682Z

Quaternion    +0.000000,+0.000000,+0.000000,+0.000000

 points axis  +1.000000,+0.000000,+0.000000

 towards ECI  +0.947350,+0.293707,+0.127532

 which is     R.A.  +17.225 Decl.  +7.327

 missing      R.A.  +21.790 Decl.  +9.155 (ibex-sun)

 error is     R.A.   +4.565 Decl.  +1.828

 for a total  4.873 deg


Lo Normal mode for the entire orbit.


There is no overlap with orbit 602 commands by manual inspection or by checking at


http://ibex.unh.edu/cgi-bin/ats.cgi.


Command Approval Checklist is attached.


Ken


On Sun, Apr 2, 2023 at 12:30 PM Perry, Timothy E [US] (SP) <Timothy.Perry@ngc.com> wrote:

All, 

   Attached are the planning files for Orbit #603.  Please respond to this thread with comments and approvals.   

Approvals are required by 0200, 03 April 2023. 

  

All, 

    We will be deleting the timed commands for orbit 603 & 604 tonight and up-linking a version 2 Orbit 603 ATS with apogee and perigee sun maneuvers. We are experiencing a star tracker issue that prohibits us from safely performing an inertial maneuver. Here are the changes to note for the new version 2 ATS for orbit 603. 

 

Tonight’s contact: 

IBEX,USHI02,ADD,04/03/23,093,08:00:00,04/03/23,093,09:00:00,,LAHO 2K IBEX-3 Orbit# 603 SC Replace ATS/Blind Acq Contact 40re Asc   

   This will be blind acquisition. The transmitter off command for this contact is in the ATS. A separate transmitter off command will be uplinked at AOS just in case I am not able to up-link the ATS.  

                       

The apogee Descending commands: 

 Original descending commands started to execute @2023/04:04:10:01:48 and now they will be executing @2023/04:04:19:59:40. So, it is important to complete ATS replacement prior to the execution of these commands @2023/04:04:10:01:48. 

 

The apogee contact has been moved: 

IBEX,USHI01,DELETE,04/04/23,094,15:00:00,04/04/23,094,15:35:00,,LAHO 2K IBEX-3 Orbit# 603 Apogee Tracking Contact 43re APO 

IBEX,USHI01,ADD,04/05/23,095,13:00:00,04/05/23,095,13:35:00,,LAHO 2K IBEX-3 Orbit# 603 Apogee Tracking Contact 43re Desc   

The original Inertial maneuver executed @ 2023/04:04:11:57:46 and the new sun maneuver executes @2023/04:04:21:55:38. So the apogee contact had to be moved.  

 

The SSR contact at perigee has been extended to dump both orbits 602 and 603 data.  

IBEX,USHI01,DELETE,04/09/23,099,03:00:00,04/09/23,099,04:00:00,,LAHO 160K IBEX-3 Orbit# 603 SSR_Dump/Tracking Contact 13re Desc 

IBEX,USHI01,ADD,04/09/23,099,03:00:00,04/09/23,099,04:30:00,,LAHO 160K IBEX-3 Orbit# 603 SSR_Dump/Tracking Contact 13re Desc  

 

All Contact changes have been confirmed at the time of the ATS generation.  

 

 

Please note the following: 

  1. Apogee Sun Maneuver  04/04/2023 21:55:38 

 

  1. Perigee Sun Maneuver 04/09/2023 02:23:57 

 

3.       Battery Balancing this orbit 

Begin 04/09/2023 10:00:00– End 04/09/2023 11:30:00 

 

4.       Command Load Constraint Violation Report (CCVR) 

IBEX_2023_090_o0603a_v002.ccvr 

# Input files:         1 

#   IBEX_2023_090_o0603a_v002.scr 

 

========================== 

HARD CONSTRAINT VIOLATIONS 

========================== 

NO VIOLATIONS. 

 

========================== 

SOFT CONSTRAINT VIOLATIONS 

========================== 

IBX-CLC-006: Planned transmission at 2023/04/09 02:58:00 UTC - 2023/04/09 

             04:32:00 UTC exceeds the maximum contiguous transmission time of 

             5400 seconds 

IBX-CLC-016: No command to enable spin pulse protection was found after 

             transition to science mode at 2023/03/31 16:53:53 UTC 

IBX-CLC-016: No command to enable spin pulse protection was found after 

             transition to science mode at 2023/04/04 23:10:44 UTC 

 

============== 

OTHER MESSAGES 

============== 

NO MESSAGES.Â