[Isocops] IBEX Orbit #645 ATS Approval (April 18 - 27, 2024) Both Orbit 645 and Pre-Eclipse

Sun Apr 7 10:14:58 EDT 2024

Hi all,
I have looked at the orbit 0645 ATS file, IBEX_2024_108_o0645a_v001.scr and I approve.

The constraint violations in IBEX_2024_108_o0645a_v001.ccvr are from the removal of the ACT_SetSpinPulseProtectEnable Enable commands, having continuous transmitter on during the eclipse rehersal, and the battery wattage dropping for the eclipse rehersal. The violations are acceptable.

The PL commands in IBEX_2024_108_o0645a_v001.scr match those in the STF, IBEX_2024_108_o0645a_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_2024_108_o0645a_v001.oef and as verified with ibex_orbit.

There are 2 star tracker outages this orbit. Outage begins at 2024-04-24 22:34:32 and lasts for 35.3 hours. Outage begins at 2024-04-26 16:19:57 and lasts for 6.6 hours.

The ground station command sequences are correct and the timing and bit rates match those in the contacts file, IBEX_Orbit645_Contacts.txt for all contacts (6).

No Battery Balancing this orbit.

The Inertial maneuver at perigee of orbit 0644 left us pointing in safe directions for the orbit 0645 arc A ascending and descending sequences:

ibex_rotate -o -u 0.900853,0.401802,0.164376 -w ibex-sun -t 2024/04:18:08:37:32
Quaternion    +0.000000,+0.000000,+0.000000,+0.000000
points axis  +1.000000,+0.000000,+0.000000
towards ECI  +0.900853,+0.401802,+0.164376
which is     R.A.  +24.038 Decl.  +9.461
missing      R.A.  +26.433 Decl. +10.901 (ibex-sun)
error is     R.A.   +2.395 Decl.  +1.440
for a total  2.762 deg

ibex_rotate -o -u 0.900853,0.401802,0.164376 -w ibex-sun -t 2024/04:21:22:52:45
Quaternion    +0.000000,+0.000000,+0.000000,+0.000000
points axis  +1.000000,+0.000000,+0.000000
towards ECI  +0.900853,+0.401802,+0.164376
which is     R.A.  +24.038 Decl.  +9.461
missing      R.A.  +29.843 Decl. +12.187 (ibex-sun)
error is     R.A.   +5.805 Decl.  +2.726
for a total  6.319 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 0.865027,0.464154,0.190501 -w ibex-sun -t 2024/04:22:00:35:53
Quaternion    +0.000000,+0.000000,+0.000000,+0.000000
points axis  +1.000000,+0.000000,+0.000000
towards ECI  +0.865026,+0.464154,+0.190501
which is     R.A.  +28.217 Decl. +10.982
missing      R.A.  +29.911 Decl. +12.212 (ibex-sun)
error is     R.A.   +1.694 Decl.  +1.230
for a total  2.065 deg

ibex_rotate -o -u 0.865027,0.464154,0.190501 -w ibex-sun -t 2024/04:22:02:10:59
Quaternion    +0.000000,+0.000000,+0.000000,+0.000000
points axis  +1.000000,+0.000000,+0.000000
towards ECI  +0.865026,+0.464154,+0.190501
which is     R.A.  +28.217 Decl. +10.982
missing      R.A.  +29.973 Decl. +12.235 (ibex-sun)
error is     R.A.   +1.756 Decl.  +1.253
for a total  2.128 deg

ibex_rotate -o -u 0.865027,0.464154,0.190501 -w ibex-sun -t 2024/04:26:10:21:31
Quaternion    +0.000000,+0.000000,+0.000000,+0.000000
points axis  +1.000000,+0.000000,+0.000000
towards ECI  +0.865026,+0.464154,+0.190501
which is     R.A.  +28.217 Decl. +10.982
missing      R.A.  +34.042 Decl. +13.660 (ibex-sun)
error is     R.A.   +5.825 Decl.  +2.678
for a total  6.289 deg

The Inertial precession maneuver at perigee leaves us pointing in safe directions at the time of the maneuver and at orbit 0646 apogee:

ibex_rotate -o -u 0.823456,0.524094,0.21736 -w ibex-sun -t 2024/04:26:13:48:09
Quaternion    +0.000000,+0.000000,+0.000000,+0.000000
points axis  +1.000000,+0.000000,+0.000000
towards ECI  +0.823456,+0.524094,+0.217360
which is     R.A.  +32.475 Decl. +12.554
missing      R.A.  +34.170 Decl. +13.698 (ibex-sun)
error is     R.A.   +1.695 Decl.  +1.144
for a total  2.009 deg

ibex_rotate -o -u 0.823456,0.524094,0.21736 -w ibex-sun -t 2024-05-01T09:55:22
Quaternion    +0.000000,+0.000000,+0.000000,+0.000000
points axis  +1.000000,+0.000000,+0.000000
towards ECI  +0.823456,+0.524094,+0.217360
which is     R.A.  +32.475 Decl. +12.554
missing      R.A.  +38.781 Decl. +15.210 (ibex-sun)
error is     R.A.   +6.306 Decl.  +2.656
for a total  6.673 deg

There is no overlap with orbit 0644 commands.

Command Approval Checklist is attached.

Carol

--
Carol Weaver
University of New Hampshire
503-902-8492

From: Perry, Timothy E [US] (SP) <Timothy.Perry at ngc.com>
Date: Wednesday, April 3, 2024 at 15:17
To: Carol Weaver <carol.weaver at unh.edu>, Chubin, Eric [US] (SP) <Eric.Chubin at ngc.com>, David Heirtzler <David.Heirtzler at unh.edu>, ADS-IBEX at l3harris.com <ADS-IBEX at l3harris.com>, IBEXOPS at gmail.com <IBEXOPS at gmail.com>, isocops at lists.sr.unh.edu <isocops at lists.sr.unh.edu>, kwfairchild at gmail.com <kwfairchild at gmail.com>, Kenneth Fairchild <Ken.Fairchild at unh.edu>, angoldconsulting at earthlink.net <angoldconsulting at earthlink.net>, Paul.Janzen at mso.umt.edu <Paul.Janzen at mso.umt.edu>, Perry, Timothy E [US] (SP) <Timothy.Perry at ngc.com>, Tyler, Ryan S [US] (SP) <Ryan.Tyler at ngc.com>, Wesley, Sheral R [US] (SP) <Sheral.Wesley at ngc.com>, Wynn, Reese [US] (SP) <Reese.Wynn at ngc.com>
Subject: IBEX Orbit #645 ATS Approval (April 18 - 27, 2024) Both Orbit 645 and Pre-Eclipse
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 #645. Please respond to this thread with comments and approvals. Approvals for the Orbit 645 ATS are required by COB, 07 April 2024.

Approvals for the Pre-Eclipse ATS are required by COB 16 April 2024.

Please note the following:

Battery Balancing

Since we are setting the eclipse Flag for the upcoming eclipse rehearsal, I didn’t see the need to add balancing commands at perigee.

Eclipse Flag True: 2024/04/17 20:00:00

Eclipse Flag False: 2024/04/17 21:30:00

Command Load Constraint Violation Report (CCVR)

IBEX_2024_108_o0645a_v001.ccvr

# Input files:         1

#   IBEX_2024_108_o0645a_v001.scr

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

HARD CONSTRAINT VIOLATIONS

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

NO VIOLATIONS.

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

SOFT CONSTRAINT VIOLATIONS

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

The IBX-CLC-006 violations are expected since we have the long duration contacts planned on the 19th and 20th.

The IBX-CLC-015 Violation is flagging due to the long transmitter times. Why it starts so early and ends on the 22nd I’m not sure. I think the long transmitter durations are throwing off the power model.  I checked the MPS timeline, and it does show valid power after 2024/04/22 05:48:11. But, from past experience we should be power positive for the duration.

IBX-CLC-006: Planned transmission at 2024/04/19 11:58:00 UTC - 2024/04/19

             14:58:00 UTC exceeds the maximum contiguous transmission time of

             5400 seconds

IBX-CLC-006: Planned transmission at 2024/04/19 14:58:00 UTC - 2024/04/19

             15:02:00 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 11040.000 seconds)

IBX-CLC-006: Planned transmission at 2024/04/20 05:28:00 UTC - 2024/04/20

             15:02:00 UTC exceeds the maximum contiguous transmission time of

             5400 seconds

IBX-CLC-015: Battery charge falls below minimum from 2024/04/17 13:48:39 UTC -

             2024/04/22 05:48:11 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 2024/04/18 07:08:06 UTC

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

             transition to science mode at 2024/04/22 01:40:59 UTC

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

OTHER MESSAGES

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

NO MESSAGES.

Timothy E.Perry
CRS IBEX OCO-2
Mission Operations
timothy.perry at ngc.com<mailto:timothy.perry at ngc.com>
Office (703) 406-5976
IBEX MOC (703)404-7470
Cell (301) 606-1430

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