PDS_VERSION_ID = PDS3 RECORD_TYPE = STREAM OBJECT = TEXT PUBLICATION_DATE = 1999-04-22 NOTE = "MGS RST Instrument Health Report HEA9112A.TXT" END_OBJECT = TEXT END Miscellaneous ============= Status (as of yesterday afternoon) of the MGS spacecraft from Stu Spath (LMCO), relayed by Bruce Waggoner (JPL): Sequencing. The first 16-hour ANS sequence was loaded Tuesday night (4/20) and went active Wednesday (4/21) morning. This sequence spends roughly 3 orbits in array normal spin with the stuck HGA boresight pointed at Earth, then spends about 1 orbit in sun'star'init with the +X axis pointing roughly at the sun, and then repeats the cycle. During ANS, the spacecraft is spinning but not processing stars, and is receiving 2K engineering data. During SSI, the spacecraft is spinning and processing stars during the eclipse, and receives no data. Wednesday afternoon a new sequence was uplinked which extended this same sequencing for 10 days. Flight Troubleshooting. The first HGA gimbal troubleshooting test was performed this afternoon on the spacecraft. Due to unfamiliarity with the step mode commanding and due to polarity differences between rate mode and step mode, rate mode was used during this first test. The expected position of the azimuth gimbal was 41.03°. Using GDE side-2, the gimbal was commanded to a position of 41.50°, then to 40.75°, then to 41.03°, and then powered off. Results of Test 1. The initial power up showed that the azimuth gimbal was no longer at 41.03°, but rather at 41.30°. When the gimbal was commanded to 41.50°, there was a delay of about 3 seconds prior to motion start. The gimbal was able to achieve the 41.5° target (with a 2 encoder count overshoot). When the gimbal was commanded back to 40.75°, it moved to about 41.35° and then began jittering about that position, much like it had during the recent contingency mode entry. No further motion was observed, and the HGA was then powered off. Future Tests. On Thursday (4/22) at 0730 mountain time, a similar test will be performed which commands the gimbal to 42.35°, and then back to 40.35°. Results are expected on the ground at about 0800 mountain. A powered hold test has been proposed for Thursday evening but not yet approved. This test would apply powered hold to azimuth and elevation gimbals for 58 minutes, and then remove powered hold from elevation. Power hold will be maintained on azimuth for 8 hours. The purpose of this test would be to get a thermal estimate of the integrity of the MLI blanket near the azimuth gimbal. Failure Theories. There are two leading failure theories right now. First, that a blanket was pulled into the azimuth gimbal and is impeding the motion. Second is a problem with the cable management which has somehow obstructed the gimbal motion. Engineering Data ================ Engineering Data Statistical Summary from CSV2STAT: First SCET: 1999-04-20T00:51:04.774 Last SCET: 1999-04-20T23:30:00.765 CHANNL CHANNEL TITLE DN-LO DN-HI EU-LO EU-HI EU-AVG/STDEV RECDS ------ ------------- ----- ----- --------- --------- ---------/-------- ----- F-0190 HGA_AZ_ANG 2933 2933 7.16E-01 7.16E-01 7.16E-01/2.97E-09 139 F-0195 HGA_EL_ANG -6433 -6433 -1.57E+00 -1.57E+00 -1.57E+00/0.00E+00 139 L-0036 MOT1_TLM_MOD 1 1 285 L-0046 MOT2_TLM_MOD 0 0 285 L-0053 RF_SW_OSC 2 2 285 L-0060 TWTA1_FILMNT 1 1 285 L-0061 TWTA1_HV 0 0 285 L-0070 TWTA2_FILMNT 1 1 285 L-0071 TWTA2_HV 1 1 285 L-0080 USO_PWR 0 0 285 L-0111 MOT1_RCV_AGC 178 255 -1.53E+02 -1.29E+02 -1.32E+02/5.28E-01 72 L-0121 MOT2_RCV_AGC 255 255 -1.53E+02 -1.53E+02 -1.53E+02/0.00E+00 72 L-0131 TWTA1_HLX_I 28 31 5.17E-01 5.77E-01 5.44E-01/1.80E-03 69 L-0141 TWTA2_HLX_I 19 21 3.26E-01 3.66E-01 3.47E-01/1.78E-03 69 T-0302 EPC1_T 148 155 1.26E+01 1.55E+01 1.42E+01/7.50E-02 69 T-0303 EPC2_T 149 160 1.05E+01 1.51E+01 1.38E+01/1.25E-01 73 T-0312 TWT1_T 196 204 1.83E+01 2.21E+01 2.07E+01/8.83E-02 72 T-0313 TWT2_T 214 219 8.56E+00 1.23E+01 1.08E+01/9.57E-02 71 L-0200, L-0201, and T-0315 are not reported. Open Loop Data ============== Data Collection --------------- We have transferred the following open loop data to Stanford: YYYY/DDD DSS DSP SAMP BW DSP BIT REC RECS RECS MAX START STOP RATE MODE RESN LEN MSSG SNR -------- --- -------- -------- ---- ---- ---- ---- ---- ----- ---- ----- 1999/111 34 14:02:00 14:12:00 5000 2000 2 12 1666 3001 0 45.0 1999/111 34 15:18:00 15:27:00 5000 2000 2 12 1666 2701 0 43.2 1999/111 34 16:02:59 17:04:47 5000 2000 2 12 1666 18543 0 43.1 1999/111 34 17:16:00 17:24:00 5000 2000 2 12 1666 2401 0 43.1 1999/111 34 17:57:00 18:07:00 5000 2000 2 12 1666 3001 0 43.2 1999/111 65 23:09:00 23:17:00 5000 2000 2 12 1666 2401 0 43.2 1999/111 65 23:51:00 23:58:00 5000 2000 2 12 1666 2101 0 43.5 1999/112 65 01:08:00 01:14:00 5000 2000 2 12 1666 1801 0 43.1 1999/112 65 01:49:00 01:56:00 5000 2000 2 12 1666 2101 0 43.4 Anomalies --------- No data were collected from SPC 10; the DSP was not included in the link. Data starting 1999/111-14:02:00 are saturated at egress and for about 60 seconds after -- until the attenuator was reset. Data starting 1999/111-15:18:00 and 1999/111-17:16:00 are among the best we have seen since the HGA azimuth gimbal anomaly. Carrier frequency is well-centered and stable, amplitude baseline prior to ingress is very stable, and there are no obvious artifacts. Data starting 1999/111-16:02:59 include about 55 minutes of noise, which will be useful in defining SPC 40 filter characteristics for future reduction of surface echo data. Data from DSS 65 show somewhat more carrier amplitude fluctuation (up to +/- 0.3 dB) than data from DSS 34, but otherwise seem very good given the circumstances. Closed Loop Data ================ Data Collection --------------- We have obtained the following files from OSCAR and EPIC: Original File Name Name on SOPC -------------------------------- ------------ ODF: 99110O111_10S.SJO;1 9110111A.ODF Ancillary Data ============== Data Collection --------------- We have obtained the following files from the FIS: Original File Name Name on SOPC -------------------------------- ------------ SAK: mgs_solar_array_1999-110.ck 9110110A.SAK SOE: mz003a.00.tsoe 9112120A.SOE SOE: mz003a.01.tsoe 9112120B.SOE