All,

Note: Angle at descending after apogee sun precession maneuver: 3.994 deg

I have looked at the orbit 627 ATS,

IBEX_2023_308_o0627a_v002.scr,

and I approve.

The only constraint violations in

IBEX_2023_308_o0627a_v001.ccvr

are from the removal of the

ACT_SetSpinPulseProtectEnable Enable

commands (2) and the second eclipse; the violations are expected.

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_2023_308_o0627a_v001.oef,

and as verified with ibex_orbit.

There is one star tracker outage. The outage starts about one day after 15 Re ascending and runs for 4- days.

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

IBEX_Orbit627_Contacts.txt,

for all contacts (3).

We are not doing battery cell balancing because there are two eclipses near perigee.

The inertial precession maneuver at perigee of orbit 626 leaves us pointing in safe directions for the orbit 627 arc A ascending and descending sequences:

ibex_rotate -o -u -0.771645,-0.579957,-0.261178 -w ibex-sun -t 2023/11:05:11:26:22

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

points axis +1.000000,+0.000000,+0.000000

towards ECI -0.771645,-0.579957,-0.261178

which is R.A. +216.928 Decl. -15.140

missing R.A. +220.035 Decl. -15.602 (ibex-sun)

error is R.A. +3.107 Decl. +0.462

for a total 3.031 deg

ibex_rotate -o -u -0.771645,-0.579957,-0.261178 -w ibex-sun -t 2023/11:09:10:22:12

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

points axis +1.000000,+0.000000,+0.000000

towards ECI -0.771645,-0.579957,-0.261178

which is R.A. +216.928 Decl. -15.140

missing R.A. +223.933 Decl. -16.722 (ibex-sun)

error is R.A. +7.005 Decl. +1.582

for a total 6.919 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 +224.007 -d -16.743 -w ibex-sun -t 2023/11:09:12:10:20

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

points axis +1.000000,+0.000000,+0.000000

towards ECI -0.688763,-0.665294,-0.288079

which is R.A. +224.007 Decl. -16.743

missing R.A. +224.007 Decl. -16.743 (ibex-sun)

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

for a total 0.000 deg

ibex_rotate -o -r +224.007 -d -16.743 -w ibex-sun -t 2023/11:09:13:40:26

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

points axis +1.000000,+0.000000,+0.000000

towards ECI -0.688763,-0.665294,-0.288079

which is R.A. +224.007 Decl. -16.743

missing R.A. +224.069 Decl. -16.760 (ibex-sun)

error is R.A. +0.062 Decl. +0.017

for a total 0.062 deg

ibex_rotate -o -r +224.007 -d -16.743 -w ibex-sun -t 2023/11:13:11:31:01

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

points axis +1.000000,+0.000000,+0.000000

towards ECI -0.688763,-0.665294,-0.288079

which is R.A. +224.007 Decl. -16.743

missing R.A. +228.028 Decl. -17.843 (ibex-sun)

error is R.A. +4.021 Decl. +1.100

for a total 3.994 deg

The inertial precession maneuver at perigee leaves us pointing in safe directions at the time of the maneuver and at orbit 628 apogee:

ibex_rotate -o -u -0.662293,-0.683815,-0.30621 -w ibex-sun -t 2023/11:13:13:36:58

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

points axis +1.000000,+0.000000,+0.000000

towards ECI -0.662293,-0.683815,-0.306210

which is R.A. +225.916 Decl. -17.831

missing R.A. +228.121 Decl. -17.871 (ibex-sun)

error is R.A. +2.205 Decl. +0.040

for a total 2.099 deg

ibex_rotate -o -u -0.662293,-0.683815,-0.30621 -w ibex-sun -t 2023-11-18T11:26:27.449Z

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

points axis +1.000000,+0.000000,+0.000000

towards ECI -0.662293,-0.683815,-0.306210

which is R.A. +225.916 Decl. -17.831

missing R.A. +233.183 Decl. -19.121 (ibex-sun)

error is R.A. +7.267 Decl. +1.290

for a total 7.012 deg

Lo Normal mode for the entire orbit.

There is no overlap with orbit 626 commands by manual inspection or by checking at

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

Command Approval Checklist is attached.

Ken

On Tue, Oct 24, 2023 at 9:50 PM Perry, Timothy E [US] (SP) <Timothy.Perry@ngc.com> wrote:

All,

    I am sending out a version 2 of the Orbit 627 ATS. An error was noted on the Long Eclipse Flag setting it too false. The original time was 2023/11/13 22:35:00 and it should have been set to 2023/11/13 22:55:00. I did a hand edit on the ats and changed the version to version #2. The new ATS has been placed on the ops server and the version 1 has been removed.

    Tim

From: Perry, Timothy E [US] (SP) <Timothy.Perry@ngc.com>
Sent: Monday, October 23, 2023 3:35 PM
To: carol.weaver@unh.edu; Chubin, Eric [US] (SP) <Eric.Chubin@ngc.com>; David.Heirtzler@unh.edu; ADS-IBEX@l3harris.com; IBEXOPS@gmail.com; isocops@lists.sr.unh.edu; kwfairchild@gmail.com; Ken.Fairchild@unh.edu; angoldconsulting@earthlink.net; 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 #627 ATS Approval ( Nov 5 – 13, 2023)

All,

   Attached are the planning files for Orbit #627. Please respond to this thread with comments and approvals. Approvals are required by COB 25 Oct 2023

Please note the following:

1.        Perigee Eclipse’s

The eclipse flag has been set for the second eclipse.

Eclipse #1 2023/11/13 18:17:37– 2023/11/13 18:52:09

Eclipse #2 2023/11/13 21:20:51 – 2023/11/13 22:31:42

Long Eclipse Flag TRUE 2023/11/13 20:00:00

Long Eclipse Flag FALSE 2023/11/13 22:35:00

2.        Command Load Constraint Violation Report (CCVR)

IBEX_2023_308_o0627a_v001.ccvr

# Input files:         1

#   IBEX_2023_308_o0627a_v001.scr

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

HARD CONSTRAINT VIOLATIONS

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

NO VIOLATIONS.

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

SOFT CONSTRAINT VIOLATIONS

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

IBX-CLC-015: Battery charge falls below minimum from 2023/11/13 22:35:00 UTC -

             2023/11/14 08:32:00 UTC. Lowest charge level is 0.000000

             watt-minutes during this interval.

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

             transition to science mode at 2023/11/05 09:51:51 UTC

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

             transition to science mode at 2023/11/09 13:10:26 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