NOAA Office of Satellite and Product Operations

NOAA 18 ADACS Subsystem Summary

Component Description Status
ESA Earth Sensor Assembly Green
MIMU-1 Miniature Inertial Measurement Unit -1 Yellow
MIMU-2 Miniature Inertial Measurement Unit -2 Yellow
PTC 1A Pitch Torque Coil 1A Green
PTC 1B Pitch Torque Coil 1B Green
PTC 2A Pitch Torque Coil 2A Green
PTC 2B Pitch Torque Coil 2B Green
RWA S Skew Reaction Wheel Assembly Green
RWA X X-axis Reaction Wheel Assembly Green
RWA Y Y-axis Reaction Wheel Assembly Green
RWA Z Z-axis Reaction Wheel Assembly Green
RYTC 1A Roll-Yaw Torque Coil 1A Green
RYTC 1B Roll-Yaw Torque Coil 1B Green
RYTC 2A Roll-Yaw Torque Coil 2A Green
RYTC 2B Roll-Yaw Torque Coil 2B Green
SSA Sun Sensor Assembly Green

Subsystem History:

Date Time Component Description
07/16/2015 13:21:58 MIMU-1 telemetry data
07/16/2015 11:45:48 MIMU-1 To gather MIMU raw data at a 10 Hz rate by overwriting all CPUA telemetry data
01/13/2015 14:59:51 MIMU-1 Attitude mode set to GYE.
04/8/2014 14:19:41 ESA Load new ESA quadrant 1 coefficients to non-control SCP.
04/2/2014 13:50:17 ESA Load new ESA quadrant 1 coefficients to control SCP.
03/7/2014 17:46:19 MIMU-1 MIMU1 Z Gryo Failed. No impact to spacecraft attitude since failure.
10/8/2013 14:46:46   Disable thruster firing
09/16/2013 13:48:21 ESA Disable the use of ESA quadrant 1 for 14 orbits
08/27/2013 17:31:00 ESA Clear ESA Ground Quadrant Use Word to 0000
08/27/2013 14:10:32 ESA Set ESA Ground Quadrant Use Word to 0001
08/10/2012 17:32:21   Enable Thruster Firing
08/10/2012 17:30:49   Put ADACS back to Nominal mode
08/10/2012 10:48:30   Exiting RGYRO ESTX mode
08/08/2012 16:14:30   Going into RGYRO ESTX mode to test new ESA coefficients for sun/moon intuitions on the ESA quad detectors.
08/08/2012 16:13:54   Disable thruster firing
02/23/2012 21:26:42   Enable thruster firing
02/23/2012 21:25:27   Put ADACS back to Nominal mode
02/23/2012 17:53:56 MIMU-1 End MIMU1 GYE test
02/21/2012 18:17:09 MIMU-1 Start MIMU1 GYE Test
02/21/2012 15:13:38 MIMU-1 Start MIMU1 ESTX test
02/21/2012 13:26:42   Disable thruster firing
10/19/2011 20:54:50   Enable thruster firing
10/19/2011 20:53:42   Put ADACS back to nominal mode
10/19/2011 17:37:12   End ESTX MIMU2 test
10/19/2011 12:42:01   Start ESTX MIMU2 test
10/19/2011 12:34:09   Disable thruster firing
09/21/2011 15:57:31   Enable thruster firing
09/21/2011 15:56:10   Put ADACS back to nominal mode
09/21/2011 12:35:42   End ESTX MIMU1 test
09/20/2011 12:47:15   Start ESTX MIMU1 test
09/20/2011 12:45:29   Disable thruster firing
04/17/2011 18:45:09   Enables GN2 Thrusters and Auto Thruster Firing Software
04/17/2011 18:44:06   Clears ADACS Yaw Update Limit and Forced YGC flags, and then commands the ADACS to Nominal mode
04/17/2011 15:41:35   End RGYRO mode test - ESTX
04/16/2011 12:34:08   Setup to start RGYRO mode test - ESTX
08/17/2010 20:31:00   End Test 2 - Gyroless mode using MIMU2
08/17/2010 20:31:00 MIMU-1 MIMU 1 ON for end of Test 2 - Gyroless mode using MIMU2
08/17/2010 20:31:00 MIMU-2 MIMU 2 OFF - end of Test 2 - Gyroless mode using MIMU2
08/17/2010 20:20:07 MIMU-2 MIMU2 ON for Test 2 - Gyroless mode using MIMU2
08/17/2010 20:20:07 MIMU-1 MIMU 1 OFF for Test 2 - Gyroless mode using MIMU2.
08/17/2010 20:20:07   Begin Test 2 - Gyroless mode using MIMU2
08/11/2010 13:09:43   End Test 1 Gyroless mode using MIMU1.
08/10/2010 11:41:16   Began Test 1 Gyroless mode using MIMU1.
10/06/2009 17:15:00   Extract MIMU LIM data to CPUTLM7 for Control OBP
10/06/2009 15:51:00   Extract MIMU LIM data to CPUTLM7 for Non-Control OBP
06/16/2009 18:26:54   Disable CPU Switching due to MIMU Failure, control-CPU
06/16/2009 18:26:26   Disable CPU Switching due to MIMU Failure, non-control CPU
06/15/2009 18:37:55   Increase pitch RWA bias from 1600 RPM to 2500 RPM, control CPU (Critical CMD)
06/15/2009 18:37:11   Increase pitch RWA bias from 1600 RPM to 2500 RPM, non-control CPU (Critical CMD)
06/11/2009 17:40:28   Clear MIMU Switch due to Go/NoGo for non-control CPU
06/11/2009 17:39:57   Clear MIMU Switch due to Go/NoGo for control CPU
06/11/2009 17:39:24   Clear the SUBCYCER error counter
06/11/2009 17:38:53   Bias the pitch wheel to 1600RPM (Critical CMD)
06/11/2009 17:38:13   Change gas unloading threshold for pitch axis momentum from 45 in/lbs/sec (2Dhex) to 145 in/lbs/sec (91hex), control CPU
06/11/2009 17:37:47   Change gas unloading threshold for pitch axis momentum from 45 in/lbs/sec (2Dhex) to 145 in/lbs/sec (91hex), non-control CPU
06/10/2009 00:00:00 MIMU-2 NOAA-18 MIMU2 failure
06/09/2009 16:37:51   Clear the X-Axis Thruster counters
06/09/2009 16:37:22   Z-Axis Thruster (NACTZ)
06/09/2009 16:37:07   Clear the X-Axis Thruster counters
06/09/2009 16:36:50   X-Axis Thruster (NACTX)
06/09/2009 16:36:31   Monitors thrurster activity
06/09/2009 16:33:42   Clears ADACS Yaw Update Limit and Forced YGC flags, and then commands the ADACS to Nominal mode
06/08/2009 21:42:00   Enable Coil Switching
06/08/2009 21:42:00   Force YGC
06/08/2009 21:42:00 RYTC 1B Swap back to primary coil
06/07/2009 19:48:00 RYTC 1B Swapped RY Coil due to MIMU Swap
06/07/2009 18:47:14 MIMU-2 At 18:47:22z on 7 June 2009 (JD158), S/C tripped into YGC following an unexpected attitude disturbance.
12/09/2008 18:08:42   Enables Auto Thruster Firings for both CPUs
12/09/2008 18:07:30   Change gas unloading threshold for pitch axis momentum from 40 in/lbs/sec (28hex) to 45 in/lbs/sec for both CPUs (2Dhex)
11/13/2008 17:38:00   Disable yaw, roll, pitch reasonableness tests in control and non-control SCP.
08/19/2008 00:33:00   Disables gas and automatic thruster firing.
08/18/2008 18:15:00   4 miscompares, ARRTLM Val=1 AMIMSWIN Val=1 AMIMUON1 Val=1 AMIMUON2 Val=0. A thruster unload was executed by the spacecraft. Additional control logic enabled in case of a close approach with debris from the Chineses Sat. Onboard s/w initated the thruster pulse (+ pitch) when the momentum threshold was exceeded. During the + pitch thruster firing the ROLL reasonableness test failed on the NON control side, which caused the MIMU to switch from MIMU 2 to MIMU 1, and set MIMU switching to INHIBIT.
08/18/2008 09:30:00   Enables Auto Thruster Firings
01/25/2006 12:00:00 PTC 1A Pitch torquer coil inactive while spacecraft Z-momentum (pitch) transitions from a positive value range to a negative value range (while Z-Rwheel does the exactly the opposite). Considered rare but not anomalous.
11/03/2005 12:00:00 PTC 1A Pitch torquer coil inactive while spacecraft Z-momentum (pitch) transitions from a negative value range to a positive value range (while Z-Rwheel does the exactly the opposite). Considered rare but not anomalous. Transition complete on 18 Nov 05.
05/27/2005 18:50:00   End reduced gyro test. COmmand ADACS back to nominal mode using all gyro axisÆ.
05/27/2005 17:07:00   Reduced gyro test, estimate pitch. Knockout out pitch gyro for 1 rev.
05/25/2005 14:20:00   New ephemeris loaded to control OBP.
05/23/2005 13:00:00   Attitude control commanded to NOMINAL mode (from YGC).
05/22/2005 19:45:00   Subtracted 3 full seconds from command clock because of drift.
05/22/2005 19:40:00   First on-orbit ephemeris upload to N18 spacecraft, nominal execution.
05/21/2005 12:20:00 ESA ESA to nominal algorythm. Spacecraft remains in YGC attitude control mode.
05/20/2005 21:55:00 PTC 2A on orbit, standby mode
05/20/2005 21:55:00 PTC 1B on orbit, in use
05/20/2005 21:55:00 PTC 1A on orbit, in use
05/20/2005 21:55:00 PTC 2B on orbit, standby mode
05/20/2005 21:50:00 RYTC 1B on orbit, in use
05/20/2005 21:50:00 RYTC 1A on orbit, in use
05/20/2005 15:00:00   Spacecraft attitude control in YGC mode
05/20/2005 11:52:00 RWA Z on orbit, in use
05/20/2005 11:51:00 MIMU-2 on orbit
05/20/2005 11:51:00 RWA Y on orbit, in use
05/20/2005 11:50:00 RWA S on orbit, standby mode
05/20/2005 11:50:00 RYTC 2B on orbit, standby mode
05/20/2005 11:50:00 RYTC 2A on orbit, standby mode
05/20/2005 11:50:00 MIMU-1 on orbit
05/20/2005 11:50:00 SSA on orbit
05/20/2005 11:50:00 RWA X on orbit, in use
09/24/1988 10:36:00 IMU On Orbit