Hi all,

The angle at descending after the Apogee Sun Maneuver is 4.201 deg.

I have looked at the orbit 0550 ATS file, IBEX_2021_338_o0550a_v001.scr and I approve.

The constraint violations in IBEX_2021_338_o0550a_v001.ccvr are from the removal of the ACT_SetSpinPulseProtectEnable Enable commands. The violations are acceptable.

The PL commands in IBEX_2021_338_o0550a_v001.scr match those in the STF, IBEX_2021_338_o0550a_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_338_o0550a_v001.oef and as verified with ibex_orbit.

There is 1 star tracker outage this orbit lasting ~85 hours resulting in an apogee Sun Maneuver.

The ground station command sequences are correct and the timing and bit rates match those in the contacts file, IBEX_Orbit550_Contacts.txt for all contacts (3).

No Battery Balancing this orbit

The inertial maneuver at perigee of orbit 0549 left us pointing in safe directions for the orbit 0550 arc A ascending and descending sequences:

ibex_rotate -o -u -0.320209,-0.865499,-0.385197 -w ibex-sun -t 2021/12:04:15:32:56

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

points axis +1.000000,+0.000000,+0.000000

towards ECI -0.320209,-0.865499,-0.385197

which is R.A. +249.697 Decl. -22.656

missing R.A. +250.960 Decl. -22.303 (ibex-sun)

error is R.A. +1.263 Decl. +0.353

for a total 1.219 deg

ibex_rotate -o -u -0.320209,-0.865499,-0.385197 -w ibex-sun -t 2021/12:08:17:00:13

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

points axis +1.000000,+0.000000,+0.000000

towards ECI -0.320209,-0.865499,-0.385197

which is R.A. +249.697 Decl. -22.656

missing R.A. +255.357 Decl. -22.743 (ibex-sun)

error is R.A. +5.660 Decl. +0.087

for a total 5.222 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 +255.438 -d -22.749 -w ibex-sun -t 2021/12:08:18:48:21

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

points axis +1.000000,+0.000000,+0.000000

towards ECI -0.231868,-0.892583,-0.386695

which is R.A. +255.438 Decl. -22.749

missing R.A. +255.438 Decl. -22.749 (ibex-sun)

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

for a total 0.000 deg

ibex_rotate -o -r +255.438 -d -22.749 -w ibex-sun -t 2021/12:08:20:18:27

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

points axis +1.000000,+0.000000,+0.000000

towards ECI -0.231868,-0.892583,-0.386695

which is R.A. +255.438 Decl. -22.749

missing R.A. +255.505 Decl. -22.755 (ibex-sun)

error is R.A. +0.067 Decl. +0.006

for a total 0.062 deg

ibex_rotate -o -r +255.438 -d -22.749 -w ibex-sun -t 2021/12:12:22:26:14

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

points axis +1.000000,+0.000000,+0.000000

towards ECI -0.231868,-0.892583,-0.386695

which is R.A. +255.438 Decl. -22.749

missing R.A. +259.983 Decl. -23.103 (ibex-sun)

error is R.A. +4.545 Decl. +0.354

for a total 4.201 deg

The Inertial precession maneuver at perigee leaves us pointing in safe directions at the time of the maneuver and at orbit 0551 apogee:

ibex_rotate -o -u -0.132337,-0.905367,-0.403481 -w ibex-sun -t 2021/12:13:01:44:09

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. +260.143 Decl. -23.118 (ibex-sun)

error is R.A. +1.541 Decl. +0.678

for a total 1.568 deg

ibex_rotate -o -u -0.132337,-0.905367,-0.403481 -w ibex-sun -t 2021-12-17T23:56:14

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. +265.618 Decl. -23.362 (ibex-sun)

error is R.A. +3.934 Decl. +0.434

for a total 3.631 deg

There is no overlap with orbit 0549 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: Monday, 2021-November-22 at 12:51
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 #550 ATS Approval (04 – 13 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 #550. Please respond to this thread with comments and approvals.

Approvals are required by 16:00, 24 Nov 2021

Please note the following:

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

No Battery Balancing this orbit

Command Load Constraint Violation Report (CCVR)

IBEX_2021_338_o0550a_v001.ccvr

# Input files: 1

# IBEX_2021_338_o0550a_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 2021/12/04 13:08:31 UTC

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

transition to science mode at 2021/12/08 19:48:27 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