Hi all,

Note: Angle at orbit 502 apogee after the perigee sun precession maneuver: 0.299 deg

I have looked at the orbit 502 ATS files: IBEX_2020_269_o0502a_INST_v001.scr, IBEX_2020_269_o0502a_BUS_v001.scr and I approve.

The only constraint violations in IBEX_2020_269_o0502a_INST_v001.ccvr and IBEX_2020_269_o0502a_BUS_v001.ccvr are from the removal of the ACT_SetSpinPulseProtectEnable Enable commands (2); the violations are expected.

The PL commands in IBEX_2020_269_o0502a_INST_v001.scr match those in IBEX_2020_269_o0502a_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_2020_269_o0502a_BUS_v001.oef and as verified with the crossing times report.

There are two star tracker outages due to the moon. The first one lasts ~52 hours and ends shortly before Apogee on 2020-09-29. The second one is around the 16 Re descending crossing and lasts ~21 hours through perigee on 2020-10-04.

The ground station command sequences are correct and the timing and bit rates match those in the contacts file, IBEX_Orbit502_Contacts.txt for the (4) contacts.

No battery cell balancing.

The inertial precession maneuver at perigee of orbit 501 left us pointing in a safe direction for the orbit 502 arc A ascending and descending sequences:

ibex_rotate -o -u -0.999951,0.007365,-0.006562 -w ibex-sun -t 2020/09:25:08:55:10

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

points axis +1.000000,+0.000000,+0.000000

towards ECI -0.999951,+0.007365,-0.006562

which is R.A. +179.578 Decl. -0.376

missing R.A. +182.286 Decl. -1.009 (ibex-sun)

error is R.A. +2.708 Decl. +0.633

for a total 2.781 deg

ibex_rotate -o -u -0.999951,0.007365,-0.006562 -w ibex-sun -t 2020/09:29:19:00:37

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

points axis +1.000000,+0.000000,+0.000000

towards ECI -0.999951,+0.007365,-0.006562

which is R.A. +179.578 Decl. -0.376

missing R.A. +186.160 Decl. -2.649 (ibex-sun)

error is R.A. +6.582 Decl. +2.273

for a total 6.961 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 -0.997212,-0.063858,-0.038615 -w ibex-sun -t 2020/09:29:20:43:45

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

points axis +1.000000,+0.000000,+0.000000

towards ECI -0.997212,-0.063858,-0.038615

which is R.A. +183.664 Decl. -2.213

missing R.A. +186.226 Decl. -2.675 (ibex-sun)

error is R.A. +2.562 Decl. +0.462

for a total 2.601 deg

ibex_rotate -o -u -0.997212,-0.063858,-0.038615 -w ibex-sun -t 2020/09:29:22:18:51

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

points axis +1.000000,+0.000000,+0.000000

towards ECI -0.997212,-0.063858,-0.038615

which is R.A. +183.664 Decl. -2.213

missing R.A. +186.286 Decl. -2.700 (ibex-sun)

error is R.A. +2.622 Decl. +0.487

for a total 2.664 deg

ibex_rotate -o -u -0.997212,-0.063858,-0.038615 -w ibex-sun -t 2020/10:03:21:55:37

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

points axis +1.000000,+0.000000,+0.000000

towards ECI -0.997212,-0.063858,-0.038615

which is R.A. +183.664 Decl. -2.213

missing R.A. +190.015 Decl. -4.301 (ibex-sun)

error is R.A. +6.351 Decl. +2.088

for a total 6.675 deg

The sun precession maneuver at perigee leaves us pointing in safe directions at the time of the maneuver and at orbit 503 apogee

ibex_rotate -o -r 190.285 -d -4.430 -w ibex-sun -t 2020/10:03:21:55:37

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

points axis +1.000000,+0.000000,+0.000000

towards ECI -0.980992,-0.178011,-0.077241

which is R.A. +190.285 Decl. -4.430

missing R.A. +190.015 Decl. -4.301 (ibex-sun)

error is R.A. +0.270 Decl. +0.129

for a total 0.299 deg

ibex_rotate -o -r 190.285 -d -4.430 -w ibex-sun -t 2020/10:08:20:53:12

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

points axis +1.000000,+0.000000,+0.000000

towards ECI -0.980992,-0.178011,-0.077241

which is R.A. +190.285 Decl. -4.430

missing R.A. +194.413 Decl. -6.146 (ibex-sun)

error is R.A. +4.128 Decl. +1.716

for a total 4.454 deg

There is no overlap with Orbit 501 commands by manual inspection or by checking at http://ibex.unh.edu/cgi-bin/ats.cgi.

Command Approval Checklist is attached.

Carol

Carol Weaver

University of New Hampshire

503.902.8492

From: "Perry, Timothy E [US] (IS)" <Timothy.Perry@ngc.com>
Date: Tuesday, 8 September 2020 at 14:51
To: "Weaver, Carol" <Carol.Weaver@unh.edu>, "Chubin, Eric [US] (IS)" <Eric.Chubin@ngc.com>, "Heirtzler, David" <David.Heirtzler@unh.edu>, IBEX FDG <IBEX@applieddefense.info>, IBEXOPS <IBEXOPS@gmail.com>, ISOC <isocops@lists.sr.unh.edu>, Ken Fairchild <fair-play@comcast.net>, "Ken Fairchild (kwfairchild@gmail.com)" <kwfairchild@gmail.com>, Nigel Angold <angoldconsulting@earthlink.net>, Paul Janzen <paul.janzen@umontana.edu>, "Perry, Timothy E [US] (IS)" <Timothy.Perry@ngc.com>, "Tyler, Ryan S [US] (IS)" <Ryan.Tyler@ngc.com>, "Wesley, Sheral R [US] (IS)" <Sheral.Wesley@ngc.com>, "Wynn, Reese [US] (IS)" <Reese.Wynn@ngc.com>
Subject: IBEX Orbit #502 ATS Approval (25 Sept 20 - 4 Oct 20)

Caution - External Email

All,

Attached are the planning files for Orbit #502

Please respond to this thread with comments and approvals.

Approvals are required by COB on 10 September 2020

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.

No Battery Balancing this orbit

PERIGEE: Sun Maneuver - $TIME=2020/10:04:04:47:58

Orbit# 500 Reset Master Timer - 2020/09:16:07:15:00

Command Load Constraint Violation Report (CCVR)

IBEX_2020_269_o0502a_v001.ccvr

# Input files: 1

# IBEX_2020_269_o0502a_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 2020/09/25 03:57:39 UTC

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

transition to science mode at 2020/09/29 21:48:51 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