NOAA Office of Satellite and Product Operations

NOAA 14 EPS Subsystem Summary

Component Description Status
ADESolar Array Drive ElectronicsGreen
BAT 1Battery # 1Green
BAT 2Battery # 2Green
BAT 3Battery # 3Green
BRU 1Battery Reconditioning Unit 1Green
BRU 2Battery Reconditioning Unit 2Green
BRU 3Battery Reconditioning Unit 3Green
PSEPower Supply ElectronicsGreen
SASolar ArrayGreen
SADSolar Array DriveGreen
SATCUSolar Array Telemetry Commutator UnitGreen
SHUNT ASolar Array Shunt Drive AYellow
SHUNT BSolar Array Shunt Drive BGreen


Subsystem History:

Date Time Component Description
09/30/200605:50:00 SADBIAS activated and Mode Controller autonomously swapped after bus voltage surged to over 31 volts due to minimal power load (all payloads except SARR off, most TCE's also off.)
09/29/200618:30:00BAT 3Battery commanded back to low rate charge.
09/29/200602:21:20BAT 3Battery running excessively warm, autonomously dropped to trickle charge.
09/28/200618:51:08PSEMajor spacecraft attitude perturbation resulted in autonomous PSE mode controller switch.
09/28/200614:47:20SADMajor spacecraft attitude perturbation resulted in autonomous SAD swap with possible mechanical and power production impacts.
09/22/200610:31:00 Sun-moon eclipse event occurred on 2 sequential orbits between 10:31z and 12:50z. Deepest percentage of solar array occlusion was approx. 85%.
03/28/200608:30:00 Sun-moon eclipse event occurred on 3 sequential orbits between 08:30z and 11:30z. Deepest percentage of solar array occlusion was approx. 50%.
11/22/200513:56:00BAT 1Changes VT levels on BAT-1 to 6/9 (from 7/9) on BAT-2 to 7/9 (from 8/9) and on BAT-3 to 6/9 (from 7/9).
11/22/200513:55:00SAMove array from present offset of -45 degs to a new offset of -50 degs to ease shunt loading.
11/17/200513:20:00BAT 1Power balance reconfiguration. Changes VT levels on all three batteries from 6/9, 7/8, 6/9 to 7/9, 8/9, and 7/9
10/19/200514:35:00BAT 1Change VT levels on batteries 1, 2 and 3 to 6/9. 7/9, 6/9 (from 7/11, 8/11, 7/11) respectively.
10/19/200514:30:00SAMove solar array to -45 degree offset from the sun (from -55 degs)
10/03/200509:27:00SASun-Moon eclipse occurred on spacecraft on one rev from 09:27 through 09:42Z. No reconfigurations required in preparation for this event. Maximum array percentage loss at peak eclipse was 25% down to 180 mAmps. No battery discharge resulted.
04/08/200517:59:00SASun-Moon eclipse occured on spacecraft from 17:59 through 18:12Z. No reconfigurations required in preparation for this event. Maximum array percentage loss at peak eclipse was 23% down to 187 mAmps.
02/10/200517:55:00 Changed flight software to make battery V/T curves 7/11, 8/11 and 7/11 as well as lowered minimum battery voltage for safe state trigger to 18.98
10/14/200412:30:00SASolar eclipse intermittently for 4 hours between 00:30 and 04:30. No reconfigurations required, Spacecraft remained nominal throughout.
04/19/200412:00:00SASolar eclipse intermittently for 4 hours between 11:00 and 15:00 No reconfigurations required, Spacecraft remained nominal throughout.
03/30/200411:00:00 N14 starting new, permanent, eclipse season to last throughout 2004 averaging 21% darkness per orbit.
03/30/2004 Eclipse season for 2004 started on 30 Mar. Season will last throughout and beyond 2004.
11/24/200312:45:00SASolar eclipse for 10 minutes. 18% was maximum percent shading on solar array. Spacecraft remained nominal.
11/23/200322:44:00SASolar eclipse for 20 minutes. 75% was maximum percent shading on solar array. Spacecraft remained nominal.
11/23/200320:55:00SASolar eclipse for 8 minutes. 12% was maximum percent shading on solar array. Spacecraft remained nominal.
08/21/200313:30:00SAChange the solar array offset to -55 from -45 degrees.
08/15/200319:00:00 Eclipse season for 2003 ENDED on 15 Aug 03 at 19:00Z
06/19/200318:20:00SAChange array offset to -45 degrees from -50.
06/12/200318:05:00SAChange solar array offset to -50 degrees from -55.
05/02/200312:30:00 Eclipse season for 2003 started on 2 May 03 at 13:55Z
04/30/200317:10:00PSECommand PSE Mode controller to Primary from backup.
04/30/200317:10:00PSECommand PSE Boost Regulator to Primary from backup
04/29/200319:00:00SHUNT AMove array to -55 degree offset to reduce power production because of shunt degradation
04/29/200305:15:00SHUNT AMode controller and boost regulator switched to backup from primary after surge in bus voltage, caused by shunt degradation.
12/04/200201:00:00SASolar eclipse event
08/08/200215:10:00BAT 1Battery-1 charge rates changed from LOW RATE to TRICKLE
08/08/200215:10:00BAT 2Battery-2charge rates changed from LOW RATE to TRICKLE
08/08/200215:10:00BAT 3Battery-3 charge rates changed from LOW RATE to TRICKLE
07/27/2002SAEclipse Season for 2002 Ends
06/11/200201:50:00SASolar Eclipse Event
06/10/200221:30:00SASolar Eclipse Event
05/15/2002SAEclipse Season Sfor 2002 starts
05/14/200218:15:00BAT 1Battery-1 charge rates changed from TRICKLE to LOW RATE
05/14/200218:15:00BAT 2Battery-2 charge rates changed from TRICKLE to LOW RATE
05/14/200218:15:00BAT 3Battery-3 charge rates changed from TRICKLE to LOW RATE
04/30/200219:30:00SASA Offset changed to -40 from -20
09/18/200115:00:00SASolar Array offset changed from -65 to -20 degs to unshade the sun sensor.
08/11/2001SAEclipse Season for 2001 Ends
08/08/200119:05:00BAT 1Battery-1 charge rates changed from LOW RATE to TRICKLE
08/08/200119:05:00BAT 2Battery-2 charge rates changed from LOW RATE to TRICKLE
08/08/200119:05:00BAT 3Battery-3 charge rates changed from LOW RATE to TRICKLE
05/02/200119:20:00BAT 1Battery-1 charge rates changed from TRICKLE to LOW RATE
05/02/200119:20:00BAT 2Battery-2 charge rates changed from TRICKLE to LOW RATE
05/02/200119:20:00BAT 3Battery-3 charge rates changed from TRICKLE to LOW RATE.
04/29/200102:40:00BAT 1Battery-1 charge rates changed from LOW RATE to TRICKLE
04/29/200102:40:00BAT 2Battery-2 charge rates changed from LOW RATE to TRICKLE
04/29/200102:40:00BAT 3Battery-3 charge rates changed from LOW RATE to TRICKLE
04/28/200118:20:00BAT 1Switched VT Limits from 6/9 to 8/11 due to high battery voltage
04/28/200118:20:00BAT 2Switched VT Limits from 7/9 to 9/11 due to high battery voltage
04/28/200118:20:00BAT 3Switched VT Limits from 6/9 to 8/11 due to high battery voltage
04/26/200113:45:00BAT 1Battery-1 charge rates changed from TRICKLE to LOW RATE
04/26/200113:45:00BAT 2Battery-2 charge rates changed from TRICKLE to LOW RATE
04/26/200113:45:00BAT 3Battery-3 charge rates changed from TRICKLE to LOW RATE.
04/26/2001SAEclipse season for 2001 starts
02/18/2000SASolar Array Offset changed from -55 deg to +35 deg to improve data quality of playbacks due to possible RF reflection from the back of the solar array.
12/30/199410:36:00BAT 1On Orbit
12/30/199410:36:00BAT 2On Orbit
12/30/199410:36:00BAT 3On Orbit
12/30/199410:36:00BRU 1On Orbit
12/30/199410:36:00BRU 2On Orbit
12/30/199410:36:00BRU 3On Orbit
12/30/199410:36:00SHUNT AOn Orbit
12/30/199410:36:00SHUNT BOn Orbit
12/30/199410:36:00SAOn Orbit
12/30/199410:36:00SADOn Orbit
12/30/199410:36:00PSEOn Orbit
12/30/199410:36:00ADEOn Orbit
12/30/199410:36:00SATCUOn Orbit