All,

I have looked at the orbit 490 ATS files,

IBEX_2020_158_o0490a_BUS_v001.scr
 
and
 
IBEX_2020_158_o0490a_INST_v001.scr,
 
and I approve.
 
The only constraint violations in
 
IBEX_2020_158_o0490a_BUS_v001.ccvr
 
and
 
IBEX_2020_158_o0490a_INST_v001.ccvr
 
are from the removal of the

ACT_SetSpinPulseProtectEnable Enable

commands (2); the violations are expected.
 
The PL commands in
 
IBEX_2020_158_o0490a_INST_v001.scr
 
match those in the v002 STF,
 
IBEX_2020_158_o0490a_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_2020_158_o0490a_BUS_v001.oef,
 
and as verified with ibex_orbit.
 
There is one star tracker outage.  The outage starts about 2.5 hours after 15 Re descending and runs for about 9 hours (delaying the maneuver).  No despinning should 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_Orbit490_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 489 left us pointing in safe directions for the orbit 490 arc A ascending and descending sequences:

ibex_rotate -o -u 0.279738,0.884416,0.373571 -w ibex-sun -t 2020/06:06:23:11:42
Quaternion +0.000000,+0.000000,+0.000000,+0.000000
points axis +1.000000,+0.000000,+0.000000
towards ECI +0.279738,+0.884416,+0.373571
which is R.A. +72.448 Decl. +21.936
missing R.A. +75.206 Decl. +22.718 (ibex-sun)
error is R.A. +2.758 Decl. +0.782
for a total 2.668 deg

ibex_rotate -o -u 0.279738,0.884416,0.373571 -w ibex-sun -t 2020/06:10:12:48:06
Quaternion +0.000000,+0.000000,+0.000000,+0.000000
points axis +1.000000,+0.000000,+0.000000
towards ECI +0.279738,+0.884416,+0.373571
which is R.A. +72.448 Decl. +21.936
missing R.A. +78.949 Decl. +23.049 (ibex-sun)
error is R.A. +6.501 Decl. +1.113
for a total 6.108 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 0.208432,0.901311,0.379731 -w ibex-sun -t 2020/06:10:14:31:14
Quaternion +0.000000,+0.000000,+0.000000,+0.000000
points axis +1.000000,+0.000000,+0.000000
towards ECI +0.208432,+0.901311,+0.379731
which is R.A. +76.979 Decl. +22.317
missing R.A. +79.024 Decl. +23.055 (ibex-sun)
error is R.A. +2.045 Decl. +0.738
for a total 2.026 deg

ibex_rotate -o -u 0.208432,0.901311,0.379731 -w ibex-sun -t 2020/06:10:16:06:20
Quaternion +0.000000,+0.000000,+0.000000,+0.000000
points axis +1.000000,+0.000000,+0.000000
towards ECI +0.208432,+0.901311,+0.379731
which is R.A. +76.979 Decl. +22.317
missing R.A. +79.094 Decl. +23.061 (ibex-sun)
error is R.A. +2.115 Decl. +0.744
for a total 2.088 deg

ibex_rotate -o -u 0.208432,0.901311,0.379731 -w ibex-sun -t 2020/06:15:02:19:08
Quaternion +0.000000,+0.000000,+0.000000,+0.000000
points axis +1.000000,+0.000000,+0.000000
towards ECI +0.208432,+0.901311,+0.379731
which is R.A. +76.979 Decl. +22.317
missing R.A. +83.681 Decl. +23.327 (ibex-sun)
error is R.A. +6.702 Decl. +1.010
for a total 6.259 deg

The inertial precession maneuver at perigee leaves us pointing in safe directions at the time of the maneuver and at orbit 491 apogee:

ibex_rotate -o -u0.132901,0.912901,0.385938 -w ibex-sun -t 2020/06:15:14:54:49
Quaternion +0.000000,+0.000000,+0.000000,+0.000000
points axis +1.000000,+0.000000,+0.000000
towards ECI +0.132901,+0.912901,+0.385938
which is R.A. +81.717 Decl. +22.702
missing R.A. +84.190 Decl. +23.322 (ibex-sun)
error is R.A. +2.473 Decl. +0.620
for a total 2.359 deg

ibex_rotate -o -u0.132901,0.912901,0.385938 -w ibex-sun -t 2020-06-20T02:58:11.256Z
Quaternion +0.000000,+0.000000,+0.000000,+0.000000
points axis +1.000000,+0.000000,+0.000000
towards ECI +0.132901,+0.912901,+0.385938
which is R.A. +81.717 Decl. +22.702
missing R.A. +88.904 Decl. +23.442 (ibex-sun)
error is R.A. +7.187 Decl. +0.740
for a total 6.653 deg

No Lo O-mode.

There is no overlap with orbit 489 commands by manual inspection or by checking at


Command Approval Checklist is attached.

Ken

 
On May 11, 2020 at 4:23 PM "Perry, Timothy E [US] (IS)" <Timothy.Perry@ngc.com> wrote:

All,

   Attached are the planning files for Orbit #490

Please respond to this thread with comments and approvals.  

Approvals are required by COB on  14 May 2020

 

Please note the following:

  1. I generated 3 separate ATS files BUS, INST and a complete file. The BUS and INST will be the files to be uplinked. The complete ATS, I used as a sanity check to see how the commands lined up. Since we are in a new phase of ATS generation. IF you have any ideas of doing this differently, let me know.

 

  1. The 3 ATS files have been changed to word docx files and encrypted. I will send out another email with the password. The files that have been transferred via MFT have not been encrypted and are still text files.  

 

  1. I moved the 2 House Keeping  commands from the INST ATS to the BUS ATS. I commented out the 2 commands in the INST ATS. If for some reason we were unable to uplink the INST Commands for this orbit, we would have been in the wrong spacecraft state for executing the maneuver commands.

 

  1. No Battery Balancing this orbit

 

  1. Perigee Maneuver

Due to a star tracker outage there will be a large gap between the execution of the housekeeping command and the start of the inertial maneuver.

# 2020-06-15T05:00:49.102Z,StarTrackerOutageStart,dueTo:earth,orbit:490 

# 2020-06-15T14:07:06.949Z,StarTrackerOutageStop,dueTo:earth,orbit:490 

Housekeeping command executes @ 2020/06:15:04:12:01

Maneuver Starts @ 2020/06:15:14:44:49

 

6.       Master Reset Timer command for Orbit #488  will execute @2020/05:29:02:15:00

 

 

Timothy E.Perry

CRS IBEX OCO-2

Mission Operations

timothy.perry@ngc.com

Office (703) 406-5976

Cell (301) 606-1430

 

cid:image001.png@01D542D6.6047A400