Hi all,

The angle at descending after the apogee sun maneuver is 4.264 deg

I have looked at the orbit 0551 ATS file, IBEX_2021_347_o0551a_v001.scr and I approve.

The constraint violations in IBEX_2021_347_o0551a_v001.ccvr are from the removal of the ACT_SetSpinPulseProtectEnable Enable commands. The violations are acceptable.

The PL commands in IBEX_2021_347_o0551a_v001.scr match those in the STF, IBEX_2021_347_o0551a_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_347_o0551a_v001.oef and as verified with ibex_orbit.

There is 1 star tracker outage this orbit that lasts for ~97 hours overlapping with the apogee maneuver.

The ground station command sequences are correct and the timing and bit rates match those in the contacts file, IBEX_Orbit551_Contacts.txt for all contacts (3).

Battery Balancing is 90 minutes long, more than 2 hours away from payload descending macros, and more than 1 hour away from maneuver.

The inertial maneuver at perigee of orbit 0550 left us pointing in safe directions for the orbit 0551 arc A ascending and descending sequences:

ibex_rotate -o -u -0.132337,-0.905367,-0.403481 -w ibex-sun -t 2021/12:13:17:48:18

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

points axis +1.000000,+0.000000,+0.000000

towards ECI -0.132337,-0.905367,-0.403481

which is R.A. +261.684 Decl. -23.796

missing R.A. +260.930 Decl. -23.194 (ibex-sun)

error is R.A. +0.754 Decl. +0.602

for a total 0.917 deg

ibex_rotate -o -u -0.132337,-0.905367,-0.403481 -w ibex-sun -t 2021/12:17:22:22:45

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

points axis +1.000000,+0.000000,+0.000000

towards ECI -0.132337,-0.905367,-0.403481

which is R.A. +261.684 Decl. -23.796

missing R.A. +265.547 Decl. -23.361 (ibex-sun)

error is R.A. +3.863 Decl. +0.435

for a total 3.567 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 +265.629 -d -23.362 -w ibex-sun -t 2021/12:18:00:10:53

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

points axis +1.000000,+0.000000,+0.000000

towards ECI -0.069966,-0.915348,-0.396539

which is R.A. +265.629 Decl. -23.362

missing R.A. +265.629 Decl. -23.362 (ibex-sun)

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

for a total 0.001 deg

ibex_rotate -o -r +265.629 -d -23.362 -w ibex-sun -t 2021/12:18:01:40:59

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

points axis +1.000000,+0.000000,+0.000000

towards ECI -0.069966,-0.915348,-0.396539

which is R.A. +265.629 Decl. -23.362

missing R.A. +265.696 Decl. -23.363 (ibex-sun)

error is R.A. +0.067 Decl. +0.001

for a total 0.062 deg

ibex_rotate -o -r +265.629 -d -23.362 -w ibex-sun -t 2021/12:22:05:40:09

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

points axis +1.000000,+0.000000,+0.000000

towards ECI -0.069966,-0.915348,-0.396539

which is R.A. +265.629 Decl. -23.362

missing R.A. +270.275 Decl. -23.422 (ibex-sun)

error is R.A. +4.646 Decl. +0.060

for a total 4.264 deg

The Inertial precession maneuver at perigee leaves us pointing in safe directions at the time of the maneuver and at orbit 0552 apogee:

ibex_rotate -o -u 0.032647,-0.912948,-0.406769 -w ibex-sun -t 2021/12:22:08:59:00

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

points axis +1.000000,+0.000000,+0.000000

towards ECI +0.032647,-0.912948,-0.406769

which is R.A. +272.048 Decl. -24.002

missing R.A. +270.436 Decl. -23.427 (ibex-sun)

error is R.A. +1.612 Decl. +0.575

for a total 1.584 deg

ibex_rotate -o -u 0.032647,-0.912948,-0.406769 -w ibex-sun -t 2021-12-27T05:12:50

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

points axis +1.000000,+0.000000,+0.000000

towards ECI +0.032647,-0.912948,-0.406769

which is R.A. +272.048 Decl. -24.002

missing R.A. +275.861 Decl. -23.313 (ibex-sun)

error is R.A. +3.813 Decl. +0.689

for a total 3.559 deg

There is no overlap with orbit 0550 commands.

Command Approval Checklist is attached.

Carol

Carol Weaver

University of New Hampshire

503.902.8492

From: Perry, Timothy E [US] (SP) <Timothy.Perry@ngc.com>
Date: Wednesday, 2021-December-1 at 12:14
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>, Wesley, Sheral R [US] (SP) <Sheral.Wesley@ngc.com>, Wynn, Reese [US] (SP) <Reese.Wynn@ngc.com>
Subject: IBEX Orbit #551 ATS Approval (13 – 22 Dec, 2021)

CAUTION: This email originated from outside of the University System. Do not click links or open attachments unless you recognize the sender and know the content is safe.

All,

Attached are the planning files for Orbit #551. Please respond to this thread with comments and approvals.

Approvals are required by 16:00, 03 Dec 2021

Please note the following:

Apogee Sun Maneuver - 2021/12:08:18:33:21

Battery Balancing this orbit

Begin 12/22/2021 15:00:00– End 12/22/2021 16:30:00

Command Load Constraint Violation Report (CCVR)

IBEX_2021_347_o0551a_v001.ccvr

# Input files: 1

# IBEX_2021_347_o0551a_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 2021/12/13 15:10:26 UTC

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

transition to science mode at 2021/12/18 01:10:59 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