From: Goddard Space Flight Center
Posted: Friday, June 20, 2003
* See note at end for latest HGA information.
* There was no weekly meeting today. See note at end for details on next week.
* A Major Flare Watch has been declared on AR10386. The campaign number is 6961.
* EIT Shutterless is today. No NRT will be available from 17-19:40 UT.
* GITT scans for the EOF and EAF are scheduled for Thursday 26 June at 9:30am.
Spacecraft Anomalies: None
Accomplished Activities: HGA test activities
Planned Activities: VIRGO, SWAN, MDI, RSL, New tracking star, mag = 7.5
Upcoming Operations: None
Ground Anomalies: None
06/19 DOY 170 - 06/20 DOY 171
EIT daily On-Line Solar Status and observations: http://umbra.nascom.nasa.gov/eit/plan/log_form20030620.html
LASCO daily On-Line Solar Status and observations: http://lasco-www.nrl.navy.mil/observations/Todays_obs.html
Web Page for Planning: http://www.bbso.njit.edu/arm
Magnetic Maps and Heliospheric Forecasts: http://www.lmsal.com/forecast/
CDS: Nominal. JOP153, EIT shutterless support, La Palma study, coronal hole spectral atlas. Weekend: Explosive events study, off-limb spectral study in the north and south, GIS spectral atlas, CME onset study, engineering, GIS QS monitoring.
UVCS: Nominal. Streamer study and synoptics.
LASCO: Nominal. C2/C3 synoptics, JOP153, JOP159.
EIT: Nominal. 195 CME watch and synoptics, JOP153, JOP159, and shutterless campaign.
MDI: Nominal. Full disk magnetograms and dopplergrams, JOP153, EIT shutterless and La Palma support.
TRACE: Nominal. La Palma support, JOP153.
Yesterday morning we tried several options to move the HGA, without success. We then decided to use both the A and B motor windings simultaneously, in an effort to increase the motor torque. This was successful and we managed to move the antenna by +4.2 deg to the "sweet spot" at -17.9 deg. 4 encoder pulses were received at exactly the right time. An attempt of operating the motor with only the A side winding after the first two pulses in the double-motor mode was unsuccessful again. In this position, we would lose about 19 days of high rate telemetry every three months, starting late next week. This would give us approximately 80% coverage.
Starting mid-week next week we expect to lose the HGA signal for ~20 days. Instruments need to prepare for this outage on Monday and Tuesday.
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