All,

I have looked at the orbit 481 ATS,

IBEX_2020_078_o0481a_v002.scr ,

and I approve.

The only constraint violations in

IBEX_2020_078_o0481a_v002_.ccvr

are from the removal of the

ACT_SetSpinPulseProtectEnable Enable

commands (2) and the proximity and timing of two contacts; the violations are expected.

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

IBEX_2020_078_o0481a_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_078_o0481a_v001.oef,

and as verified with ibex_orbit.

There are no star tracker outages.

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

IBEX_Orbit481_Contacts_v2.txt ,

for all contacts (3).

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

The inertial maneuver at perigee of orbit 480 left us pointing in safe directions for the orbit 481 arc A ascending and descending sequences:

ibex_rotate -o -u 0.997014,-0.066798,-0.038754 -w ibex-sun -t 2020/03:18:18:22:28

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

points axis +1.000000,+0.000000,+0.000000

towards ECI +0.997014,-0.066798,-0.038754

which is R.A. +356.167 Decl. -2.221

missing R.A. +358.475 Decl. -0.684 (ibex-sun)

error is R.A. +2.308 Decl. +1.537

for a total 2.772 deg

ibex_rotate -o -u 0.997014,-0.066798,-0.038754 -w ibex-sun -t 2020/03:22:07:24:15

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

points axis +1.000000,+0.000000,+0.000000

towards ECI +0.997014,-0.066798,-0.038754

which is R.A. +356.167 Decl. -2.221

missing R.A. +1.805 Decl. +0.784 (ibex-sun)

error is R.A. +354.362 Decl. +3.005

for a total 6.388 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 0.999949,0.004433,-0.009076 -w ibex-sun -t 2020/03:22:09:07:23

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

points axis +1.000000,+0.000000,+0.000000

towards ECI +0.999949,+0.004433,-0.009076

which is R.A. +0.254 Decl. -0.520

missing R.A. +1.870 Decl. +0.813 (ibex-sun)

error is R.A. +1.616 Decl. +1.333

for a total 2.095 deg

ibex_rotate -o -u 0.999949,0.004433,-0.009076 -w ibex-sun -t 2020/03:22:10:42:29

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

points axis +1.000000,+0.000000,+0.000000

towards ECI +0.999949,+0.004433,-0.009076

which is R.A. +0.254 Decl. -0.520

missing R.A. +1.930 Decl. +0.840 (ibex-sun)

error is R.A. +1.676 Decl. +1.360

for a total 2.159 deg

ibex_rotate -o -u 0.999949,0.004433,-0.009076 -w ibex-sun -t 2020/03:26:19:57:37

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

points axis +1.000000,+0.000000,+0.000000

towards ECI +0.999949,+0.004433,-0.009076

which is R.A. +0.254 Decl. -0.520

missing R.A. +5.797 Decl. +2.525 (ibex-sun)

error is R.A. +5.543 Decl. +3.045

for a total 6.323 deg

The inertial maneuver at perigee leaves us pointing in safe directions at the time of the maneuver and at orbit 482 apogee:

ibex_rotate -o -u 0.996947,0.074733,0.0226 -w ibex-sun -t 2020/03:26:23:21:07

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

points axis +1.000000,+0.000000,+0.000000

towards ECI +0.996947,+0.074733,+0.022600

which is R.A. +4.287 Decl. +1.295

missing R.A. +5.924 Decl. +2.573 (ibex-sun)

error is R.A. +1.637 Decl. +1.278

for a total 2.076 deg

ibex_rotate -o -u 0.996947,0.074733,0.0226 -w ibex-sun -t 2020-03-31T18:21:38.369Z

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

points axis +1.000000,+0.000000,+0.000000

towards ECI +0.996947,+0.074733,+0.022600

which is R.A. +4.287 Decl. +1.295

missing R.A.+10.414 Decl. +4.490 (ibex-sun)

error is R.A. +6.127 Decl. +3.195

for a total 6.903 deg

No Lo O-mode.

There is no overlap with orbit 480 commands by manual inspection or by checking at

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

Command Approval Checklist is attached.

Ken

On March 6, 2020 at 11:55 AM "Perry, Timothy E [US] (IS)" <Timothy.Perry@ngc.com> wrote:

All,

   Attached are the planning files for Orbit #481

Please respond to this thread with comments and approvals.

Approvals are required by COB on 8 Mar 2020

Please note the following:

No Battery Balancing

2.       Command Load Constraint Violation Report (CCVR)

IBEX_2020_078_o0481a_v001_.ccvr

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

HARD CONSTRAINT VIOLATIONS

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

NO VIOLATIONS.

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

SOFT CONSTRAINT VIOLATIONS

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

These 2 IBX-CLC-006 soft violations are acceptable. The 2 contacts are as follows:

USAK01,03/18/20,078,15:00:00,03/18/20,078,16:00:00, 160K IBEX-3 Orbit# 480 SSR_Dump/Tracking Contact 14re Asc

USAK01,03/18/20,078,19:00:00,03/18/20,078,20:00:00, 40K IBEX-3 Orbit# 481 HI BK Grnd Test 15.5re Asc Begin

The is a 3 hour gap between the 2 contacts. This will give the transmitters plenty of time to cool down. Also, the transmitter temp is a point that we routinely monitor.

IBX-CLC-006: Planned transmission at 2020/03/18 15:50:00 UTC - 2020/03/18

             18:58:00 UTC exceeds the maximum contiguous transmission time of

             5400 seconds

IBX-CLC-006: Planned transmission at 2020/03/18 18:58:00 UTC - 2020/03/18

             20:02:00 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 15120.000 seconds)

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

             transition to science mode at 2020/03/18 15:53:09 UTC

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

             transition to science mode at 2020/03/22 10:12:29 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