All,

Note: Angle at orbit 516 apogee after the perigee sun precession maneuver: 4.919 deg

I have looked at the orbit 515 ATS files,

IBEX_2021_020_o0515a_BUS_v001.scr

and

IBEX_2021_020_o0515a_INST_v001.scr,

and I approve.

The only constraint violations in

IBEX_2021_020_o0515a_BUS_v001.ccvr

and

IBEX_2021_020_o0515a_INST_v001.ccvr

are from the removal of the

ACT_SetSpinPulseProtectEnable Enable

commands (2); the violations are expected.

The PL commands in

IBEX_2021_020_o0515a_INST_v001.scr

match those in the v002 STF,

IBEX_2021_020_o0515a_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_2021_020_o0515a_BUS_v001.oef,

and as verified with ibex_orbit.

There are two star tracker outages. The first starts 1- day after apogee and runs for 3+ days. The second starts ~7 hours before perigee and runs for 20 minutes. 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_Orbit515_Contacts.txt,

for all contacts (3).

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

The inertial precession maneuver at perigee of orbit 514 left us pointing in safe directions for the orbit 515 arc A ascending and descending sequences:

ibex_rotate -o -u 0.52143,-0.778814,-0.348654 -w ibex-sun -t 2021/01:20:19:47:27

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

points axis +1.000000,+0.000000,+0.000000

towards ECI +0.521430,-0.778814,-0.348654

which is R.A. +303.803 Decl. -20.405

missing R.A. +302.928 Decl. -20.016 (ibex-sun)

error is R.A. +0.875 Decl. +0.389

for a total 0.908 deg

ibex_rotate -o -u 0.52143,-0.778814,-0.348654 -w ibex-sun -t 2021/01:24:11:00:44

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

points axis +1.000000,+0.000000,+0.000000

towards ECI +0.521430,-0.778814,-0.348654

which is R.A. +303.803 Decl. -20.405

missing R.A. +306.791 Decl. -19.138 (ibex-sun)

error is R.A. +2.988 Decl. +1.267

for a total 3.084 deg

The inertial 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 -u 0.588225,-0.738309,-0.329987 -w ibex-sun -t 2021/01:24:12:43:52

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

points axis +1.000000,+0.000000,+0.000000

towards ECI +0.588225,-0.738309,-0.329987

which is R.A. +308.545 Decl. -19.268

missing R.A. +306.865 Decl. -19.120 (ibex-sun)

error is R.A. +1.680 Decl. +0.148

for a total 1.594 deg

ibex_rotate -o -u 0.588225,-0.738309,-0.329987 -w ibex-sun -t 2021/01:24:14:18:58

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

points axis +1.000000,+0.000000,+0.000000

towards ECI +0.588225,-0.738309,-0.329987

which is R.A. +308.545 Decl. -19.268

missing R.A. +306.932 Decl. -19.103 (ibex-sun)

error is R.A. +1.613 Decl. +0.165

for a total 1.532 deg

ibex_rotate -o -u 0.588225,-0.738309,-0.329987 -w ibex-sun -t 2021/01:29:01:20:53

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

points axis +1.000000,+0.000000,+0.000000

towards ECI +0.588225,-0.738309,-0.329987

which is R.A. +308.545 Decl. -19.268

missing R.A. +311.456 Decl. -17.982 (ibex-sun)

error is R.A. +2.911 Decl. +1.286

for a total 3.044 deg

The sun precession maneuver at perigee leaves us pointing in safe directions at the time of the maneuver and at orbit 516 apogee:

ibex_rotate -o -r +311.599 -d -17.951 -w ibex-sun -t 2021/01:29:04:34:28

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

points axis +1.000000,+0.000000,+0.000000

towards ECI +0.631594,-0.711407,-0.308204

which is R.A. +311.599 Decl. -17.951

missing R.A. +311.599 Decl. -17.951 (ibex-sun)

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

for a total 0.000 deg

ibex_rotate -o -r +311.599 -d -17.951 -w ibex-sun -t 2021-02-02T22:28:33.842Z

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

points axis +1.000000,+0.000000,+0.000000

towards ECI +0.631594,-0.711407,-0.308204

which is R.A. +311.599 Decl. -17.951

missing R.A. +316.548 Decl. -16.586 (ibex-sun)

error is R.A. +4.949 Decl. +1.365

for a total 4.919 deg

Lo Normal mode for the entire orbit.

There is no overlap with orbit 514 commands by manual inspection or by checking at

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

Command Approval Checklist is attached.

Ken

On 01/05/2021 2:09 PM Perry, Timothy E [US] (SP) <timothy.perry@ngc.com> wrote:

All,

   Attached are the planning files for Orbit #515

Please respond to this thread with comments and approvals.

Approvals are required by COB on 10 January 2021

Please note the following:

I generated 3 separate ATS files BUS, INST and a complete file. The BUS and INST will be the files to be uplinked. The complete ATS, I used as a sanity check to see how the commands lined up. Since we are in a new phase of ATS generation. IF you have any ideas of doing this differently, let me know.

The 3 ATS files have been changed to word files and encrypted. I will send out another email with the password. The files that have been transferred via MFT have not been encrypted and are still text files.

I moved the 2 House Keeping commands from the INST ATS to the BUS ATS. I commented out the 2 commands in the INST ATS. If for some reason we were unable to uplink the INST Commands for this orbit, we would have been in the wrong spacecraft state for executing the maneuver commands.

4.       Orbit 515 Battery Balancing

2021-01-29T11:41:51.131Z,Perigee,orbit:515

Start 2021/01:29:11:00:00 - End 2021/01:29:12:30:00

5.       # Orbit# 513 Reset Master Timer - 2021/01:11:22:15:00

6.       Sun Maneuver Perigee - 2021/01:29:04:19:28

7.       Command Load Constraint Violation Report (CCVR)

IBEX_2021_020_o0515a_v001.ccvr

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

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 2021/01/20 17:26:17 UTC

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

             transition to science mode at 2021/01/24 13:48:58 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