All,

Note: Angle at descending after apogee sun precession maneuver: 4.046 deg

I have looked at the orbit 633 ATS,

IBEX_2023_363_o0633a_v001.scr,

and I approve.

The only constraint violations in

IBEX_2023_363_o0633a_v001.ccvr

are from the removal of the

ACT_SetSpinPulseProtectEnable Enable

commands (2); the violations are expected.

The PL commands in the v001 ATS match those in the v002 STF,

IBEX_2023_363_o0633a_v002.stf.

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_363_o0633a_v001.oef,

and as verified with ibex_orbit.

There are two star tracker outages. The first starts just before apogee and runs for 2+ hours. The second starts ~1.5 days after apogee and runs for 1.5 days. Some despinning may be required due to these outages.

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

IBEX_Orbit633_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 632 leaves us pointing in safe directions for the orbit 633 arc A ascending and descending sequences:

ibex_rotate -o -u 0.148078,-0.903368,-0.402491 -w ibex-sun -t 2023/12:30:03:48:01

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

points axis +1.000000,+0.000000,+0.000000

towards ECI +0.148078,-0.903368,-0.402491

which is R.A. +279.309 Decl. -23.734

missing R.A. +278.557 Decl. -23.223 (ibex-sun)

error is R.A. +0.752 Decl. +0.511

for a total 0.858 deg

ibex_rotate -o -u 0.148078,-0.903368,-0.402491 -w ibex-sun -t 2024/01:03:04:00:51

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

points axis +1.000000,+0.000000,+0.000000

towards ECI +0.148078,-0.903368,-0.402491

which is R.A. +279.309 Decl. -23.734

missing R.A. +283.032 Decl. -22.876 (ibex-sun)

error is R.A. +3.723 Decl. +0.858

for a total 3.525 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 +283.114 -d -22.868 -w ibex-sun -t 2024/01:03:05:48:59

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

points axis +1.000000,+0.000000,+0.000000

towards ECI +0.209056,-0.897373,-0.388609

which is R.A. +283.114 Decl. -22.868

missing R.A. +283.114 Decl. -22.868 (ibex-sun)

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

for a total 0.001 deg

ibex_rotate -o -r +283.114 -d -22.868 -w ibex-sun -t 2024/01:03:07:19:05

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

points axis +1.000000,+0.000000,+0.000000

towards ECI +0.209056,-0.897373,-0.388609

which is R.A. +283.114 Decl. -22.868

missing R.A. +283.181 Decl. -22.862 (ibex-sun)

error is R.A. +0.067 Decl. +0.006

for a total 0.062 deg

ibex_rotate -o -r +283.114 -d -22.868 -w ibex-sun -t 2024/01:07:07:32:56

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

points axis +1.000000,+0.000000,+0.000000

towards ECI +0.209056,-0.897373,-0.388609

which is R.A. +283.114 Decl. -22.868

missing R.A. +287.475 Decl. -22.448 (ibex-sun)

error is R.A. +4.361 Decl. +0.420

for a total 4.046 deg

The inertial precession maneuver at perigee leaves us pointing in safe directions at the time of the maneuver and at orbit 634 apogee:

ibex_rotate -o -u 0.305878,-0.869509,-0.387805 -w ibex-sun -t 2024/01:07:09:55:37

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

points axis +1.000000,+0.000000,+0.000000

towards ECI +0.305878,-0.869509,-0.387805

which is R.A. +289.381 Decl. -22.818

missing R.A. +287.584 Decl. -22.439 (ibex-sun)

error is R.A. +1.797 Decl. +0.379

for a total 1.701 deg

ibex_rotate -o -u 0.305878,-0.869509,-0.387805 -w ibex-sun -t 2024-01-12T08:15:07.568Z

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

points axis +1.000000,+0.000000,+0.000000

towards ECI +0.305878,-0.869509,-0.387805

which is R.A. +289.381 Decl. -22.818

missing R.A. +293.081 Decl. -21.722 (ibex-sun)

error is R.A. +3.700 Decl. +1.096

for a total 3.595 deg

Lo Normal mode for the entire orbit.

There is no overlap with orbit 632 commands by manual inspection or by checking at

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

Command Approval Checklist is attached.

Ken

On Fri, Dec 15, 2023 at 4:00 PM Perry, Timothy E [US] (SP) <Timothy.Perry@ngc.com> wrote:

All,

   Attached are the planning files for Orbit #633. Please respond to this thread with comments and approvals. Approvals are required by COB 19 Dec 2023

Please note the following:

1.        Battery Balancing

Eclipse Flag True: 2024/01/07 17:00:00

Eclipse Flag False: 2024/01/07 18:30:00

2.        Command Load Constraint Violation Report (CCVR)

IBEX_2023_363_o0633a_v001.ccvr

# Input files:         1

#   IBEX_2023_363_o0633a_v001.scr

==========================

HARD CONSTRAINT VIOLATIONS

==========================

NO VIOLATIONS.

==========================

SOFT CONSTRAINT VIOLATIONS

==========================

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

             transition to science mode at 2023/12/30 02:08:52 UTC

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

             transition to science mode at 2024/01/03 06:49:05 UTC

==============

OTHER MESSAGES

==============

NO MESSAGES.

Timothy E.Perry

CRS IBEX OCO-2

Mission Operations

timothy.perry@ngc.com

Office (703) 406-5976

Cell (301) 606-1430