Hi all,

Sun angle at Apogee 532 is 4.551 deg.

I have looked at the orbit 0531 ATS file, IBEX_2021_166_o0531a_v001.scr and I approve.

The constraint violations in IBEX_2021_166_o0531a_v001.ccvr are from the removal of the ACT_SetSpinPulseProtectEnable Enable commands. The violations are acceptable.

The PL commands in IBEX_2021_166_o0531a_v001.scr match those in the STF, IBEX_2021_166_o0531a_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_166_o0531a_v001.oef and as verified with ibex_orbit.

There is 1 star tracker outage this orbit. Outage lasts for ~27 hours over the perigee maneuver resulting in a sun precession maneuver.

The ground station command sequences are correct and the timing and bit rates match those in the contacts file, IBEX_Orbit531_Contacts.txt for all contacts (3).

Battery Balancing this orbit is the right length and distance from other spacecraft activities.

The Inertial maneuver at perigee of orbit 0530 left us pointing in safe directions for the orbit 0531 arc A ascending and descending sequences:

ibex_rotate -o -u 0.131669,0.913039,0.386035 -w ibex-sun -t 2021/06:16:06:10:41

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

points axis +1.000000,+0.000000,+0.000000

towards ECI +0.131669,+0.913039,+0.386035

which is R.A. +81.794 Decl. +22.708

missing R.A. +84.572 Decl. +23.324 (ibex-sun)

error is R.A. +2.778 Decl. +0.616

for a total 2.630 deg

ibex_rotate -o -u 0.131669,0.913039,0.386035 -w ibex-sun -t 2021/06:19:23:08:29

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

points axis +1.000000,+0.000000,+0.000000

towards ECI +0.131669,+0.913039,+0.386035

which is R.A. +81.794 Decl. +22.708

missing R.A. +88.440 Decl. +23.435 (ibex-sun)

error is R.A. +6.646 Decl. +0.726

for a total 6.157 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 0.057425,0.919924,0.38787 -w ibex-sun -t 2021/06:20:00:39:37

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

points axis +1.000000,+0.000000,+0.000000

towards ECI +0.057425,+0.919924,+0.387870

which is R.A. +86.428 Decl. +22.822

missing R.A. +88.507 Decl. +23.436 (ibex-sun)

error is R.A. +2.079 Decl. +0.614

for a total 2.008 deg

ibex_rotate -o -u 0.057425,0.919924,0.38787 -w ibex-sun -t 2021/06:20:02:26:43

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

points axis +1.000000,+0.000000,+0.000000

towards ECI +0.057425,+0.919924,+0.387870

which is R.A. +86.428 Decl. +22.822

missing R.A. +88.586 Decl. +23.438 (ibex-sun)

error is R.A. +2.158 Decl. +0.616

for a total 2.078 deg

ibex_rotate -o -u 0.057425,0.919924,0.38787 -w ibex-sun -t 2021/06:24:14:12:16

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

points axis +1.000000,+0.000000,+0.000000

towards ECI +0.057425,+0.919924,+0.387870

which is R.A. +86.428 Decl. +22.822

missing R.A. +93.295 Decl. +23.416 (ibex-sun)

error is R.A. +6.867 Decl. +0.594

for a total 6.343 deg

The sun precession maneuver at perigee leaves us pointing in safe directions at the time of the maneuver and at orbit 0530 apogee:

ibex_rotate -o -r +93.436 -d +23.407 -w ibex-sun -t 2021/06:24:17:38:27

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

points axis +1.000000,+0.000000,+0.000000

towards ECI -0.055001,+0.916056,+0.397260

which is R.A. +93.436 Decl. +23.407

missing R.A. +93.436 Decl. +23.407 (ibex-sun)

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

for a total 0.000 deg

ibex_rotate -o -r +93.436 -d +23.407 -w ibex-sun -t 2021-06-29T13:13:54

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

points axis +1.000000,+0.000000,+0.000000

towards ECI -0.055001,+0.916056,+0.397260

which is R.A. +93.436 Decl. +23.407

missing R.A. +98.388 Decl. +23.225 (ibex-sun)

error is R.A. +4.952 Decl. +0.182

for a total 4.551 deg

There is no overlap with orbit 0530 commands.

Command Approval Checklist is attached.

Carol

Carol Weaver

University of New Hampshire

503.902.8492

From: Wesley, Sheral R [US] (SP) <Sheral.Wesley@ngc.com>
Date: Wednesday, 2021-June-2 at 21:14
To: Carol Weaver <carol.weaver@unh.edu>, Chubin, Eric [US] (SP) <Eric.Chubin@ngc.com>, David Heirtzler <David.Heirtzler@unh.edu>, ADS-IBEX@l3harris.com <ADS-IBEX@l3harris.com>, 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>, Kenneth Fairchild <Ken.Fairchild@unh.edu>, angoldconsulting@earthlink.net <angoldconsulting@earthlink.net>, Paul.Janzen@mso.umt.edu <Paul.Janzen@mso.umt.edu>, Perry, Timothy E [US] (SP) <Timothy.Perry@ngc.com>, Tyler, Ryan S [US] (SP) <Ryan.Tyler@ngc.com>, Wynn, Reese [US] (SP) <Reese.Wynn@ngc.com>
Subject: IBEX Orbit #531 ATS Approval (15 June 21 - 25 June 21)

Caution - External Email

All,

Attached are the planning files for Orbit #531. Please respond to this thread with comments and approvals.

We will manually reset the master timer at PERIGEE starting with Orbit# 531.

Approvals are required by COB on 5 June 2021.

Please note the following:

1. The ATS file has been changed to a word file 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.

2. PERIGEE Sun Maneuver

2021-06-24T17:23:27.000Z,SunMvrBegin

2021-06-24T17:38:27.000Z,SunMvrEnd

3. Battery Balancing this orbit

Orbit# 531 PERIGEE Battery Balancing Commands

# 2021-06-25T00:00:13.964Z,Perigee,orbit:531

SetLongEclipseFlag TRUE $TIME=2021/06:25:01:00:00

SetLongEclipseFlag FALSE $TIME=2021/06:25:02:30:00

4. Command Load Constraint Violation Report (CCVR)

# Filename: IBEX_2021_166_o0531a_v001.ccvr

# File type: Command Load Constraint Violation Report (CCVR)

# Create time: 2021/153.204146

# Plan period start: 2021/167.031800

# Plan period stop: 2021/176.071200

# Default time format: UTC

# Input files: 1

# IBEX_2021_166_o0531a_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 2021/06/16 03:20:29 UTC

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

transition to science mode at 2021/06/20 01:56:43 UTC

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

OTHER MESSAGES

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

NO MESSAGES.

Sheral Wesley | Sr Principal Engineer, Satellite Systems

Northrop Grumman Corporation | Space Systems

O: 703-406-5641 | C: 202-236-0802 | sheral.wesley@ngc.com