Note:  Angle at descending after the apogee sun precession maneuver: 3.968 deg

           Angle at orbit 597 apogee after the perigee sun precession maneuver: 4.950 deg

I have looked at the orbit 596 ATS,

IBEX_2023_027_o0596a_v001.scr,

and I approve.

The only constraint violations in

IBEX_2023_027_o0596a_v001.ccvr

are from the removal of the

ACT_SetSpinPulseProtectEnable Enable

commands (2); 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_027_o0596a_v001.oef,

and as verified with ibex_orbit.

There is one star tracker outage.  The outage starts 1+ days before 15 Re descending and runs for about 2 days.  Some despinning may be required due to this outage.

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

IBEX_Orbit596_Contacts.txt,

for all contacts (3).

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 595 leaves us pointing in safe directions for the orbit 596 arc A ascending and descending sequences:

ibex_rotate -o -u 0.616646,-0.718234,-0.322315 -w ibex-sun -t 2023/01:27:22:01:40

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

 points axis  +1.000000,+0.000000,+0.000000

 towards ECI  +0.616646,-0.718234,-0.322315

 which is     R.A. +310.648 Decl. -18.803

 missing      R.A. +309.799 Decl. -18.442 (ibex-sun)

 error is     R.A.   +0.849 Decl.  +0.361

 for a total  0.882 deg

ibex_rotate -o -u 0.616646,-0.718234,-0.322315 -w ibex-sun -t 2023/01:31:21:09:54

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

 points axis  +1.000000,+0.000000,+0.000000

 towards ECI  +0.616646,-0.718234,-0.322315

 which is     R.A. +310.648 Decl. -18.803

 missing      R.A. +313.958 Decl. -17.315 (ibex-sun)

 error is     R.A.   +3.310 Decl.  +1.488

 for a total  3.481 deg

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

ibex_rotate -o -r +314.034 -d -17.293 -w ibex-sun -t 2023/01:31:22:58:02

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

 points axis  +1.000000,+0.000000,+0.000000

 towards ECI  +0.663665,-0.686430,-0.297258

 which is     R.A. +314.034 Decl. -17.293

 missing      R.A. +314.034 Decl. -17.293 (ibex-sun)

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

 for a total  0.000 deg

ibex_rotate -o -r +314.034 -d -17.293 -w ibex-sun -t 2023/02:01:00:28:08

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

 points axis  +1.000000,+0.000000,+0.000000

 towards ECI  +0.663665,-0.686430,-0.297258

 which is     R.A. +314.034 Decl. -17.293

 missing      R.A. +314.097 Decl. -17.275 (ibex-sun)

 error is     R.A.   +0.063 Decl.  +0.018

 for a total  0.063 deg

ibex_rotate -o -r +314.034 -d -17.293 -w ibex-sun -t 2023/02:04:23:50:24

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

 points axis  +1.000000,+0.000000,+0.000000

 towards ECI  +0.663665,-0.686430,-0.297258

 which is     R.A. +314.034 Decl. -17.293

 missing      R.A. +318.004 Decl. -16.158 (ibex-sun)

 error is     R.A.   +3.970 Decl.  +1.135

 for a total  3.968 deg

The sun precession maneuver at perigee leaves us pointing in safe directions at the time of the maneuver and at orbit 597 apogee:

ibex_rotate -o -r +318.126 -d -16.127 -w ibex-sun -t 2023/02:05:02:45:17

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

 points axis  +1.000000,+0.000000,+0.000000

 towards ECI  +0.715313,-0.641228,-0.277767

 which is     R.A. +318.126 Decl. -16.127

 missing      R.A. +318.126 Decl. -16.127 (ibex-sun)

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

 for a total  0.000 deg

ibex_rotate -o -r +318.126 -d -16.127 -w ibex-sun -t 2023-02-09T20:51:21.331Z

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

 points axis  +1.000000,+0.000000,+0.000000

 towards ECI  +0.715313,-0.641228,-0.277767

 which is     R.A. +318.126 Decl. -16.127

 missing      R.A. +323.010 Decl. -14.602 (ibex-sun)

 error is     R.A.   +4.884 Decl.  +1.525

 for a total  4.950 deg

Lo Normal mode for the entire orbit.

There is no overlap with orbit 595 commands by manual inspection or by checking at

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

Command Approval Checklist is attached.

Ken