Hi all,

Note: Angle at orbit 517 perigee after the apogee sun precession maneuver: 4.073 deg

I have looked at the orbit 517 ATS files,

IBEX_2021_038_o0517a_BUS_v001.scr, IBEX_2021_038_o0517a_INST_v001.scr

and I approve.

The only constraint violations in

IBEX_2021_038_o0517a_BUS_v001.ccvr, IBEX_2021_038_o0517a_INST_v001.ccvr

are from the removal of the

ACT_SetSpinPulseProtectEnable Enable

commands (2) and errors for transmissions being longer than 5400 seconds (2); the violations are expected.

The PL commands in

IBEX_2021_038_o0517a_INST_v001.scr

match those in the v002 STF,

IBEX_2021_038_o0517a_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_038_o0517a_BUS_v001.oef,

and as verified with ibex_orbit.

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

IBEX_Orbit517_Contacts.txt,

for all contacts (4).

We are not doing battery cell balancing this orbit.

The inertial maneuver at perigee of orbit 516 left us pointing in safe directions for the orbit 517 arc A ascending and descending sequences:

ibex_rotate -o -u 0.76273,-0.589271,-0.266465 -w ibex-sun -t 2021/02:07:19:48:44

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

points axis +1.000000,+0.000000,+0.000000

towards ECI +0.762730,-0.589271,-0.266465

which is R.A. +322.311 Decl. -15.454

missing R.A. +321.412 Decl. -15.152 (ibex-sun)

error is R.A. +0.899 Decl. +0.302

for a total 0.918 deg

ibex_rotate -o -u 0.76273,-0.589271,-0.266465 -w ibex-sun -t 2021/02:11:19:41:57

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

points axis +1.000000,+0.000000,+0.000000

towards ECI +0.762730,-0.589271,-0.266465

which is R.A. +322.311 Decl. -15.454

missing R.A. +325.435 Decl. -13.803 (ibex-sun)

error is R.A. +3.124 Decl. +1.651

for a total 3.444 deg

The sun 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 -r +325.506 -d -13.778 -w ibex-sun -t 2021/02:11:21:28:43

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

points axis +1.000000,+0.000000,+0.000000

towards ECI +0.800470,-0.550025,-0.238161

which is R.A. +325.506 Decl. -13.778

missing R.A. +325.506 Decl. -13.778 (ibex-sun)

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

for a total 0.000 deg

ibex_rotate -o -r +325.506 -d -13.778 -w ibex-sun -t 2021/02:11:23:00:11

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

points axis +1.000000,+0.000000,+0.000000

towards ECI +0.800470,-0.550025,-0.238161

which is R.A. +325.506 Decl. -13.778

missing R.A. +325.568 Decl. -13.756 (ibex-sun)

error is R.A. +0.062 Decl. +0.022

for a total 0.064 deg

ibex_rotate -o -r +325.506 -d -13.778 -w ibex-sun -t 2021/02:16:00:58:25

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

points axis +1.000000,+0.000000,+0.000000

towards ECI +0.800470,-0.550025,-0.238161

which is R.A. +325.506 Decl. -13.778

missing R.A. +329.447 Decl. -12.414 (ibex-sun)

error is R.A. +3.941 Decl. +1.364

for a total 4.073 deg

The inertial precession maneuver at perigee leaves us pointing in safe directions at the time of the maneuver and at orbit 518 apogee:

ibex_rotate -o -u 0.855404,-0.471118,-0.215247 -w ibex-sun -t 2021/02:11:23:00:11

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

points axis +1.000000,+0.000000,+0.000000

towards ECI +0.855404,-0.471118,-0.215247

which is R.A. +331.156 Decl. -12.430

missing R.A. +325.568 Decl. -13.756 (ibex-sun)

error is R.A. +5.588 Decl. +1.326

for a total 5.602 deg

ibex_rotate -o -u 0.855404,-0.471118,-0.215247 -w ibex-sun -t 2021/02:16:00:58:25

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

points axis +1.000000,+0.000000,+0.000000

towards ECI +0.855404,-0.471118,-0.215247

which is R.A. +331.156 Decl. -12.430

missing R.A. +329.447 Decl. -12.414 (ibex-sun)

error is R.A. +1.709 Decl. +0.016

for a total 1.669 deg

There is no overlap with orbit 516 commands by manual inspection or by checking at

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

Command Approval Checklist is attached.

Carol Weaver

University of New Hampshire

503.902.8492

From: Perry, Timothy E [US] (SP) <Timothy.Perry@ngc.com>
Date: Thursday, 2021-January-21 at 12:44
To: Weaver, Carol <Carol.Weaver@unh.edu>, Chubin, Eric [US] (SP) <Eric.Chubin@ngc.com>, Heirtzler, David <David.Heirtzler@unh.edu>, IBEX@applieddefense.info <IBEX@applieddefense.info>, IBEXOPS@gmail.com <IBEXOPS@gmail.com>, isocops@lists.sr.unh.edu <isocops@lists.sr.unh.edu>, fair-play@comcast.net <fair-play@comcast.net>, kwfairchild@gmail.com <kwfairchild@gmail.com>, angoldconsulting@earthlink.net <angoldconsulting@earthlink.net>, paul.janzen@umontana.edu <paul.janzen@umontana.edu>, Perry, Timothy E [US] (SP) <Timothy.Perry@ngc.com>, Tyler, Ryan S [US] (SP) <Ryan.Tyler@ngc.com>, Wesley, Sheral R [US] (SP) <Sheral.Wesley@ngc.com>, Wynn, Reese [US] (SP) <Reese.Wynn@ngc.com>
Subject: IBEX Orbit #517 ATS Approval (7 – 16 Feb 21)

Caution - External Email

All,

Attached are the planning files for Orbit #517

Please respond to this thread with comments and approvals.

Approvals are required by COB on 28 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.

Apogee Sun Maneuver - 2021/02:11:21:13:43

No Battery Balancing this orbit

# Orbit# 515 Master Timer Reset - 2021/01:29:02:15:00

Command Load Constraint Violation Report (CCVR)

The 2 IBX-CLC-006 Soft constraint violations are acceptable. The reason for the violations is that the 2 contacts are separated by 1 hour.

IBEX,AUWA01,ADD,02/16/21,047,13:00:00,02/16/21,047,14:30:00,LAHO 160K IBEX-2 Orbit# 517 Star Tracker Dump/Tracking Contact 14 Per Asc

IBEX,AUWA01,ADD,02/16/21,047,15:30:00,02/16/21,047,16:30:00,LAHO 160K IBEX-2 Orbit# 517 SSR_Dump/Tracking Contact 14.5 Asc

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

HARD CONSTRAINT VIOLATIONS

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

NO VIOLATIONS.

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

SOFT CONSTRAINT VIOLATIONS

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

IBX-CLC-006: Planned transmission at 2021/02/16 12:58:00 UTC - 2021/02/16

14:32:00 UTC exceeds the maximum contiguous transmission time of

5400 seconds

IBX-CLC-006: Planned transmission at 2021/02/16 15:28:00 UTC - 2021/02/16

16:32:00 UTC is preceded by one or more additional transmissions

which, when combined, exceed the maximum transmission time of 5400

seconds within a 18000-second window (total planned transmission

time this window is 9480.000 seconds)

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

transition to science mode at 2021/02/07 17:18:48 UTC

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

transition to science mode at 2021/02/11 22:30:11 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