Документ взят из кэша поисковой машины. Адрес оригинального документа : http://www.stsci.edu/ftp/observing/status_reports/old_reports_99/hst_status_12_01_99 Дата изменения: Wed Dec 1 14:46:10 1999 Дата индексирования: Sun Dec 23 11:05:58 2007 Кодировка: Поисковые слова: эта киля

HUBBLE SPACE TELESCOPE

DAILY REPORT #2510

PERIOD COVERED: 0000Z (UTC) 11/30/99 - 0000Z (UTC) 12/01/99

Daily Status Report as of 335/0000Z

1.0 OBSERVATIONS SCHEDULED AND ACCOMPLISHED:

Since HST remains in Zero Gyro Sun Point (ZGSP), no science observations
were performed.

2.0 FLIGHT OPERATIONS SUMMARY:

2.1 Guide Star Acquisitions:

No activity

2.2 FHST Updates:

No activity

2.3 Operations Notes:

The HST continues in ZGSP. For much of the day, operations and
engineering personnel participated in the PSEA/RMGA On-Orbit Test. The
following events were a part of that test. At approximately 334/1200Z, the
aperture door (AD) was closed. Then the SI C&DH was safed and the FGEs
were powered off in preparation for the PSEA test mode. The RMGA unit was
powered on. Its three gyros were observed in the test mode for
approximately one orbit. Initial reports are that the RMGA data passed the
acceptance criteria for continuing to initiate the PSEA. The thermal data
was acceptable. However, a decision was made to not to proceed with the
entry into PSEA control, but to continue in the test mode for an additional
three orbits. During this period, it was noticed that the AD had drifted
open first to about 3 degrees and then to 5 degrees (at 334/1958Z). It was
later determined that the AD movement coincided with MCU operate commands
from the PSEA. The PSEA commands the AD with every test mode initiate
command while in orbit night. The MCU register was zeroed, which was
expected to inhibit further AD movement. Later, it was discovered that
there remains a small signal in PSEA which can lead to further door
movement. HSTAR 7390 was written to document the AD occurrences.

Following the test, the FGE units were re-powered at 334/2030Z, the
NSSC-1 was recovered at 334/2050Z, and the WF/PC-2 heat pipe heater was
enabled at the same time. The RMGA was commanded off at
334/334/2120Z. Finally, the aperture door was commanded to a closed
position at 334/2252Z.

It is anticipated that the PSEA/RMGA On-Orbit Test will pick up
again on Friday.

3.0 SIGNIFICANT FORTHCOMING EVENTS:

Servicing Mission 3A, currently scheduled for December 9, 1999.

/CAW