All,

Note: Angle at descending after apogee sun precession maneuver: 4.020 deg

I have looked at the orbit 628 ATS,

IBEX_2023_317_o0628a_v001.scr,


and I approve.

The only constraint violations in

IBEX_2023_317_o0628a_v001.ccvr


are from the removal of the

ACT_SetSpinPulseProtectEnable Enable


commands (2); the violations are expected.

The PL commands in the v001 ATS match those in the v002 STF,

IBEX_2023_317_o0628a_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_2023_317_o0628a_v001.oef,


and as verified with ibex_orbit.

There is one star tracker outage.  The outage starts 1+ days after 15 Re ascending and runs for 4 days.  Some despinning may be required due to this outage.

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

IBEX_Orbit628_Contacts.txt,


for all contacts (3).

We are not doing battery cell balancing this orbit; we'll do it again in the next orbit.

The inertial precession maneuver at perigee of orbit 627 leaves us pointing in safe directions for the orbit 628 arc A ascending and descending sequences:

ibex_rotate -o -u -0.662293,-0.683815,-0.30621 -w ibex-sun -t 2023/11:14:11:13:55

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. +229.092 Decl. -18.161 (ibex-sun)

 error is     R.A.   +3.176 Decl.  +0.330

 for a total  3.038 deg


ibex_rotate -o -u -0.662293,-0.683815,-0.30621 -w ibex-sun -t 2023/11:18:09:57:10

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. +233.120 Decl. -19.107 (ibex-sun)

 error is     R.A.   +7.204 Decl.  +1.276

 for a total  6.950 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 +233.197 -d -19.124 -w ibex-sun -t 2023/11:18:11:45:18

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

 points axis  +1.000000,+0.000000,+0.000000

 towards ECI  -0.566004,-0.756511,-0.327614

 which is     R.A. +233.197 Decl. -19.124

 missing      R.A. +233.197 Decl. -19.124 (ibex-sun)

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

 for a total  0.001 deg


ibex_rotate -o -r +233.197 -d -19.124 -w ibex-sun -t 2023/11:18:13:15:24

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

 points axis  +1.000000,+0.000000,+0.000000

 towards ECI  -0.566004,-0.756511,-0.327614

 which is     R.A. +233.197 Decl. -19.124

 missing      R.A. +233.260 Decl. -19.138 (ibex-sun)

 error is     R.A.   +0.063 Decl.  +0.014

 for a total  0.061 deg


ibex_rotate -o -r +233.197 -d -19.124 -w ibex-sun -t 2023/11:22:11:50:00

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

 points axis  +1.000000,+0.000000,+0.000000

 towards ECI  -0.566004,-0.756511,-0.327614

 which is     R.A. +233.197 Decl. -19.124

 missing      R.A. +237.353 Decl. -20.033 (ibex-sun)

 error is     R.A.   +4.156 Decl.  +0.909

 for a total  4.020 deg


The inertial precession maneuver at perigee leaves us pointing in safe directions at the time of the maneuver and at orbit 629 apogee:


ibex_rotate -o -u -0.535623,-0.771177,-0.34408 -w ibex-sun -t 2023/11:22:14:10:51

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

 points axis  +1.000000,+0.000000,+0.000000

 towards ECI  -0.535624,-0.771178,-0.344081

 which is     R.A. +235.218 Decl. -20.126

 missing      R.A. +237.460 Decl. -20.059 (ibex-sun)

 error is     R.A.   +2.242 Decl.  +0.067

 for a total  2.107 deg


ibex_rotate -o -u -0.535623,-0.771177,-0.34408 -w ibex-sun -t 2023-11-27T14:29:53.333Z

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

 points axis  +1.000000,+0.000000,+0.000000

 towards ECI  -0.535624,-0.771178,-0.344081

 which is     R.A. +235.218 Decl. -20.126

 missing      R.A. +242.800 Decl. -21.066 (ibex-sun)

 error is     R.A.   +7.582 Decl.  +0.940

 for a total  7.159 deg


Lo Normal mode for the entire orbit.


There is no overlap with orbit 627 commands by manual inspection or by checking at


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


Command Approval Checklist is attached.


Ken


On Thu, Nov 2, 2023 at 7:36 PM Wesley, Sheral R [US] (SP) <Sheral.Wesley@ngc.com> wrote:

All, 

   Attached are the planning files for Orbit #628. Please respond to this thread with comments and approvals. Approvals are required by COB 3 Nov 2023 

 

Please note the following: 

Command Load Constraint Violation Report (CCVR) 

# Input files:         1

#   IBEX_2023_317_o0628a_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 2023/11/14 09:42:42 UTC

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

             transition to science mode at 2023/11/18 12:45:24 UTC

 

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

OTHER MESSAGES

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

NO MESSAGES.

 

 

 

Best Regards,

 

Sheral Wesley  |  Sr Principal Engineer, Satellite Systems

Northrop Grumman Corporation  |  Space Systems

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

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