All,

I have looked at the orbit 637 ATS,

IBEX_2024_035_o0637a_v001.scr,

and I approve.

The only constraint violations in

IBEX_2024_035_o0637a_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_2024_035_o0637a_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_2024_035_o0637a_v001.oef,

and as verified with ibex_orbit.

There is one star tracker outage. The outage starts about 12 hours before 15 Re descending and runs for 5+ hours. 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_Orbit637_Contacts.txt,

for all contacts (3).

We are not doing battery cell balancing this orbit; we'll do it again in the next orbit.

The inertial precession maneuver at perigee of orbit 636 leaves us pointing in safe directions for the orbit 637 arc A ascending and descending sequences:

ibex_rotate -o -u 0.71808,-0.6345,-0.285956 -w ibex-sun -t 2024/02:04:21:30:54

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

points axis +1.000000,+0.000000,+0.000000

towards ECI +0.718080,-0.634500,-0.285956

which is R.A. +318.536 Decl. -16.616

missing R.A. +317.692 Decl. -16.287 (ibex-sun)

error is R.A. +0.844 Decl. +0.329

for a total 0.874 deg

ibex_rotate -o -u 0.71808,-0.6345,-0.285956 -w ibex-sun -t 2024/02:08:11:59:27

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

points axis +1.000000,+0.000000,+0.000000

towards ECI +0.718080,-0.634500,-0.285956

which is R.A. +318.536 Decl. -16.616

missing R.A. +321.408 Decl. -15.117 (ibex-sun)

error is R.A. +2.872 Decl. +1.499

for a total 3.143 deg

The inertial 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 -u 0.772407,-0.579055,-0.260926 -w ibex-sun -t 2024/02:08:13:42:35

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

points axis +1.000000,+0.000000,+0.000000

towards ECI +0.772407,-0.579055,-0.260926

which is R.A. +323.142 Decl. -15.125

missing R.A. +321.479 Decl. -15.094 (ibex-sun)

error is R.A. +1.663 Decl. +0.031

for a total 1.606 deg

ibex_rotate -o -u 0.772407,-0.579055,-0.260926 -w ibex-sun -t 2024/02:08:15:17:41

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

points axis +1.000000,+0.000000,+0.000000

towards ECI +0.772407,-0.579055,-0.260926

which is R.A. +323.142 Decl. -15.125

missing R.A. +321.544 Decl. -15.072 (ibex-sun)

error is R.A. +1.598 Decl. +0.053

for a total 1.543 deg

ibex_rotate -o -u 0.772407,-0.579055,-0.260926 -w ibex-sun -t 2024/02:13:02:02:51

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

points axis +1.000000,+0.000000,+0.000000

towards ECI +0.772407,-0.579055,-0.260926

which is R.A. +323.142 Decl. -15.125

missing R.A. +325.819 Decl. -13.672 (ibex-sun)

error is R.A. +2.677 Decl. +1.453

for a total 2.973 deg

The inertial precession maneuver at perigee leaves us pointing in safe directions at the time of the maneuver and at orbit 638 apogee:

ibex_rotate -o -u 0.820389,-0.520575,-0.236567 -w ibex-sun -t 2024/02:13:04:37:31

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

points axis +1.000000,+0.000000,+0.000000

towards ECI +0.820389,-0.520575,-0.236567

which is R.A. +327.603 Decl. -13.684

missing R.A. +325.922 Decl. -13.641 (ibex-sun)

error is R.A. +1.681 Decl. +0.043

for a total 1.634 deg

ibex_rotate -o -u 0.820389,-0.520575,-0.236567 -w ibex-sun -t 2024-02-18T05:18:51.727Z

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

points axis +1.000000,+0.000000,+0.000000

towards ECI +0.820389,-0.520575,-0.236567

which is R.A. +327.603 Decl. -13.684

missing R.A. +330.953 Decl. -11.865 (ibex-sun)

error is R.A. +3.351 Decl. +1.819

for a total 3.739 deg

Lo Normal mode for the entire orbit.

There is no overlap with orbit 636 commands by manual inspection or by checking at

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

Command Approval Checklist is attached.

Ken

On Mon, Jan 22, 2024 at 11:45 AM Perry, Timothy E [US] (SP) <Timothy.Perry@ngc.com> wrote:

All,

   Attached are the planning files for Orbit #637. Please respond to this thread with comments and approvals. Approvals are required by COB 25 Jan 2024.

Please note the following:

1.        No Battery Balancing

2.        Command Load Constraint Violation Report (CCVR)

IBEX_2024_035_o0637a_v001.ccvr

# Input files:         1

#   IBEX_2024_035_o0637a_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 2024/02/04 19:43:10 UTC

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

             transition to science mode at 2024/02/08 14:47:41 UTC

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

OTHER MESSAGES

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

NO MESSAGES.

Timothy E.Perry

CRS IBEX OCO-2

Mission Operations

timothy.perry@ngc.com

Office (703) 406-5976

IBEX MOC (703)404-7470

Cell (301) 606-1430