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Polar Anomaly Timeline

POLAR Anomaly Timeline – August 2-6, 1999

214/1800-2010 Station D66 Madrid scheduled support.

214/1915 Initial acquisition at D66 (75 minutes late). Late acquisition due to
Telemetry Group Controller (TGC), Antenna Hydraulics, and Antenna Auto-Tracking.

214/1915-2000 Successful Playback of DTR 1.

214/2002 Begin Playback of DTR 2.

214/20:17:32 Station D66 loses lock on both channels.

214/2024 Station D66 reacquires Downlink Two-Way, Channels 1 and 2.

214/2025 DTR 2 Commanded to Fast-Forward Wind to recover lost dump data.

214/20:26:44 Station D66 loses lock on both channels; beginning of spacecraft anomaly. Begin telemetry data loss.

214/2027-2040 RF signal strong at site. Station receivers remained locked. TGCs unable to lock to downlink on either channel. Station reports strong RFI signal in POLAR downlink frequency. (This is later interpreted as the POLAR downlink Carrier/Sub-carrier without Telemetry Modulation.)

214/2040 Backup Comm-Off Macro scheduled to execute out of Stored Memory. Station reports seeing no change in downlink, assume station still locked to ‘RFI’ type signal. Manual comm-off commands sent with no effect.


215/0110-0210 Station D54 Madrid scheduled support. Negative acquisition. Same symptoms as previous D66 support. Downlink RF signal still strong.


215/0210 Station D61 Madrid reports strong RF signal, inability to lock to spacecraft.


215/0455-1330 Station D27 Goldstone support.

215/0530 Station D27 reports strong RF signal, inability to lock to spacecraft. Station also reports seeing Bit-Rates on both channels fluctuating wildly. This information was not reported from any of the three Madrid sites. Spacecraft anomaly confirmed by use of alternate DSN site. Additional support (LM Engineers, LM Manager, NASA Manager, CSOC CSR) called in.

215/0630 Telemetry Downlink Anomaly Contingency Procedure initiated with engineering and management approval.

215/0630 CAP Blind Switch STOL procedure executed (CCS 99-302). Procedure uplinks commands for CAP Secondary Power On, Science Telemetry Mode to CAP, GTM, RIU, and Instruments, PMP configuration (RT & PB data), and Reed-Soloman R/T Channel Reset. Station D27 reports favorable change in downlink signal, Channel 1 Bit Rate stable at 1.113 kbps.

At this point, the Primary Command and Attitude Processor (CAP-1) has been successfully recovered. There is a delay of 7 minutes, 40 seconds before the Science telemetry format takes effect following completion of one Engineering telemetry format Major Frame.

215/06:37:29 Station D27 successfully locks onto POLAR Realtime telemetry, 64.000 kbps. End telemetry data loss (10 hours, 10 minutes, 45 seconds). Spacecraft State-of-Health check begins. Spacecraft Clock reads 1995/283/00:07 (consistent with CAP reset/power cycle). Realtime telemetry is badly degraded. Problem later traced to a TGC problem at Station D27. Despun Platform (DPM) is off.

215/0725 Station D27 replaces TGC with another unit. Realtime telemetry clears up immediately.

215/0736 Spacecraft Clock commanded to GMT, 1999/215/0736.

215/0739 Battery Voltage/Temperature (V/T) Levels commanded from Level 3 (default) to Level 7 (nominal).

215/0742 Loadshed Levels set to nominal levels and Enabled.

215/0745 Shunt Driver A commanded to Amp-A.

215/0753 DTR 2 Fast-Forwarded to End-of-Tape for Playback.

215/0755 DTR 2 and 1 Configured for normal operations, Playback.

215/0759 DTR 2 Playback for data recovery.

215/0817 DTR 1 Fast-Forwarded to End-of-Tape for Playback.

215/0826 DTR 1 Playback for data recovery.

215/0836 Flight Software (FSW) Macro Heap, Macro-Static Refence Table (MSRT), Stored Command Tables (SCT) A and B dumped. Contents are all zeros. Consistent with CAP reset/power cycle.

215/0853 ACADs Command-Eye-Pulse (CEP) 1 and 3 deselected to enable Spin Rate calculations.

215/0910 Power Supply Electronics (PSE) Mode Controller commanded to Primary Side.

215/0913 VIS commands sent to safe instrument per instrumenter request.

215/1011 FSW Code Patches uplinked.

215/1130-1230 Station D16 Goldstone scheduled support. Realtime and Ranging data. Concurrent with Station D27 support.

215/1254 TIDE High Voltage off command sent to safe instrument, per instrumenter request.

215/1304 UVI commands sent to safe instrument, per instrumenter request.

Due to the absence of Macro Memory and a valid Stored Command Table, no commanding from stored memory is available at this point. Tape recorder cycles are commanded in realtime, and the comm system is activated via blind commands.


215/1600-2000 Station D46 Canberra scheduled support.

215/1604-1637 FSW Macro Heap, MSRT, and Stored Command Table A uplinked to spacecraft memory.

215/1840 EFI command sent (CCS 99-304) at instrumenter request.


215/2050-2310 Station D66 Madrid support.

MFE (CCS 99-312), EFI (CCS 99-313), and TIDE (CCS 99-314, 99-315) commands sent per instrumenter requests.


216/0020-0120 Station D66 Madrid support.

216/0127 Stored Command Table A Activated. Return to stored memory commanding of downlink cycles.


216/1210-1500 Station D27 Goldstone support.

TIMAS (CCS 99-308) and HYDRA (CCS 99-310) commanding performed per instrumenter requests. TIMAS in nominal states. MFE High-Rate data is enabled to CAP 1 (CCS 99-311).


216/2050-2310 Station D66 Madrid support.

MFE (CCS 99-312), EFI (CCS 99-313), TIDE (CCS 99-314, 99-315) commanding performed per instrumenter requests.


217/1510-1920 Station D27 Goldstone support.

217/1513 HYDRA pre-maneuver commands sent (CCS 99-316) per instrumenter request.

217/1542 RIU Enabled.

217/1543 Spacecraft commanded to Maneuver telemetry format for DPM Initialization.

217/1546 DPM FSW patches.

217/1548 Despun Platform power on and initialization.

217/1606 DPM to Normal mode.

217/1651 DPM Calibration.

217/1705 DPM commanded to High Gain mode.

217/1710 DPM Once-Per -Rev (OPR) Compensation Enabled.

217/1751 Spin Phase Refence Pulse (SPRP) Enabled.

217/1752 Magnetics Calculations Enabled.

217/1800 Spacecraft telemetry format commanded to Science mode.

217/1802 HYDRA commands sent (CCS 99-317, 99-318, 99-319) per instrumenter request. HYDRA now in nominal state.

217/1851 UVI commands sent (CCS 99-321) per instrumenter request.

217/1910-2020 Station D24 Goldstone support.

217/1853-2004 TIDE commands sent (CCS 99-320) per instrumenter request. TIDE ramped-up and in nominal state.


218/1510-2025 Station D42 Canberra support.

VIS commands for high-voltage ramp-up and software loads sent (CCS-99-322, 99-323, 99-324). VIS in nominal state.