Hi all,

Note: Angle at orbit 511 arc B descending after the apogee sun precession maneuver: 4.047 deg

I have looked at the orbit 511 ATS files IBEX_2020_350_o0511a_INST_v001.scr and IBEX_2020_350_o0511a_BUS_v001.scr and I approve.

The only constraint violations in IBEX_2020_350_o0511a_BUS_v001.ccvr and IBEX_2020_350_o0511a_INST_v001.ccvr are from the removal of the spin pulse commands and the battery charge warning from Orbit 510. All are expected.

The PL commands in IBEX_2020_350_o0511a_v002.stf match those in IBEX_2020_350_o0511a_INST_v001.scr.

Ascending and descending command sequences are consistent with each other, 15 Re ascending, the apogee maneuver time, and 15 Re descending as determined by the OEF (IBEX_2020_350_o0511a_BUS_v001.oef) and as verified with ibex_orbit and crossingtimes.

There is one star tracker outage that begins 1.75 days after 16 Re ascending and lasts for ~4 days over the time of the apogee maneuver.

The ground station command sequences are correct and the timing and bit rates matchthose in the contacts file IBEX_Orbit511_Contacts.txt for all contacts (3).

We are not doing battery cell balancing this orbit.

The inertial precession maneuver at perigee of orbit 510 left us pointing in safe directions for the orbit 511 arc A ascending and descending sequences:

ibex_rotate -o -u -0.087598,-0.909906,-0.405461 -w ibex-sun -t 2020/12:16:01:40:58

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

points axis +1.000000,+0.000000,+0.000000

towards ECI -0.087598,-0.909906,-0.405461

which is R.A. +264.501 Decl. -23.920

missing R.A. +263.794 Decl. -23.336 (ibex-sun)

error is R.A. +0.707 Decl. +0.584

for a total 0.872 deg

ibex_rotate -o -u -0.087598,-0.909906,-0.405461 -w ibex-sun -t 2020/12:20:00:08:51

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

points axis +1.000000,+0.000000,+0.000000

towards ECI -0.087598,-0.909906,-0.405461

which is R.A. +264.501 Decl. -23.920

missing R.A. +268.117 Decl. -23.415 (ibex-sun)

error is R.A. +3.616 Decl. +0.505

for a total 3.350 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 268.199 -d -23.414 -w ibex-sun -t 2020/12:20:01:56:59

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

points axis +1.000000,+0.000000,+0.000000

towards ECI -0.028840,-0.917204,-0.397372

which is R.A. +268.199 Decl. -23.414

missing R.A. +268.199 Decl. -23.414 (ibex-sun)

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

for a total 0.001 deg

ibex_rotate -o -r 268.199 -d -23.414 -w ibex-sun -t 2020/12:20:03:27:05

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

points axis +1.000000,+0.000000,+0.000000

towards ECI -0.028840,-0.917204,-0.397372

which is R.A. +268.199 Decl. -23.414

missing R.A. +268.267 Decl. -23.414 (ibex-sun)

error is R.A. +0.068 Decl. +0.000

for a total 0.062 deg

ibex_rotate -o -r 268.199 -d -23.414 -w ibex-sun -t 2020/12:24:01:48:01

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

points axis +1.000000,+0.000000,+0.000000

towards ECI -0.028840,-0.917204,-0.397372

which is R.A. +268.199 Decl. -23.414

missing R.A. +272.609 Decl. -23.397 (ibex-sun)

error is R.A. +4.410 Decl. +0.017

for a total 4.047 deg

The inertial maneuver at perigee leaves us pointing in safe directions at the time of the maneuver and at orbit 512 apogee:

ibex_rotate -o -u 0.070556,-0.911137,-0.406019 -w ibex-sun -t 2020/12:24:04:40:42

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

points axis +1.000000,+0.000000,+0.000000

towards ECI +0.070556,-0.911137,-0.406019

which is R.A. +274.428 Decl. -23.955

missing R.A. +272.749 Decl. -23.400 (ibex-sun)

error is R.A. +1.679 Decl. +0.555

for a total 1.635 deg

ibex_rotate -o -u 0.070556,-0.911137,-0.406019 -w ibex-sun -t 2020-12-29T01:18:42

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

points axis +1.000000,+0.000000,+0.000000

towards ECI +0.070556,-0.911137,-0.406019

which is R.A. +274.428 Decl. -23.955

missing R.A. +278.169 Decl. -23.211 (ibex-sun)

error is R.A. +3.741 Decl. +0.744

for a total 3.509 deg

Lo normal mode for the entire orbit.

There is no overlap with orbit 510 commands by manual inspection or by checking at http://ibex.unh.edu/cgi-bin/ats.cgi

Command approval checklist is attached.

Thanks,

Carol

Carol Weaver

University of New Hampshire

503.902.8492

From: Perry, Timothy E [US] (IS) <Timothy.Perry@ngc.com>
Date: Monday, 2020-November-30 at 14:54
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) <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@mso.umt.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 #511 ATS Approval (16 - 24 Dec 20)

Caution - External Email

All,

Attached are the planning files for Orbit #511

Since we were all off for thanksgiving. I think we can take our time and have the approvals ready for the perigee passes during orbit 509.

Please respond to this thread with comments and approvals.

Approvals are required by COB on 05 December 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

APOGEE: Sun Maneuver - $TIME=2020/12:20:01:41:59

Orbit# 509 Reset Master Timer - 2020/12:07:03:15:00

Command Load Constraint Violation Report (CCVR)

IBEX_2020_350_o0511a_v001.ccvr

The soft constraint “IBX-CLC-015” is acceptable. MPS uses a history file to calculate power usage. This message is from the solar eclipse during perigee on orbit 510.

# Input files: 1

# IBEX_2020_350_o0511a_v001.scr

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

HARD CONSTRAINT VIOLATIONS

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

NO VIOLATIONS.

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

SOFT CONSTRAINT VIOLATIONS

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

IBX-CLC-015: Battery charge falls below minimum from 2020/12/15 14:00:41 UTC -

2020/12/15 15:07:41 UTC. Lowest charge level is 6094.046263

watt-minutes during this interval.

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

transition to science mode at 2020/12/15 23:34:47 UTC

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

transition to science mode at 2020/12/20 02:57:05 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