NOAA-14 Solar Array Move, 29 April 2003 - Issued: 30 April 2003; 1230 UTC

8:33 AM
Subject: NOAA-14 Solar Array Move, 29 April 2003 - Issued: 30 April 2003; 1230 UTC

Solar Array Move May Cause Data Shifts

Date/Time(UTC) Message Issued:
30 April 2003, 1230 UTC

Satellite(s) Involved:

Instrument(s) Involved:
All instruments

Product(s) Involved/Affected:
All Products

Date/Time(UTC) of Initial Implementation:
29 April 2003, Time 1857 UTC

Details/Specifics of Change:
On April 29, SOCC issued the following notice.
"NOAA-14 hardware autonomously switched the power supply electronics to
backup. At 0512z on DOY 119, April 29, 2003, NOAA-14 experienced a
momentary 28v bus voltage in excess of 29 volts. This triggered an
autonomous switch of both the PSE mode controller and boost regulator from
primary to backup. Engineering analysis indicates this was most likely due
to degraded shunt performance. On orbit 42939, the Solar Array offset value
was commanded to 55 degrees to reduce the power. At a later date, when
shunt performance has stabilized, the mode controller and boost regulator
will be commanded back to primary." Users may notice data changes as
instrument temperature may go up or down due to the solar array shadow

Contact Person(s) Name/Email/Phone Number for Questions: ext. 117 or ext. 124

Web site(s) that contain other relevant information (where applicable): - History of level 1B
notices - All user notices - SOCC polar satellites status - SOCC morning reports

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