HUBBLE SPACE TELESCOPE DAILY REPORT #2481 PERIOD COVERED: 0000Z (UTC) 10/18/99 - 0000Z (UTC) 10/19/99 Daily Status Report as of 292/0000Z 1.0 OBSERVATIONS SCHEDULED AND ACCOMPLISHED: 1.1 Completed Three Sets of WF/PC-2 8443 (WF/PC-2 Cycle-8 Supplemental Darks pt1/3) The WF/PC-2 was used to obtain three dark frames every day to provide data for monitoring and characterizing the evolution of hot pixels. The observations were completed as planned, and no problems were reported. 1.2 Completed Two Sets of WF/PC-2 8442 (WF/PC-2 Cycle 8 Standard Darks) The WF/PC-2 was used to make a series of Cycle 8 standard dark calibration observations. This dark calibration program obtains dark frames every week in order to provide data for the ongoing calibration of the CCD dark current rate, and to monitor and characterize the evolution of hot pixels. The observations were executed as scheduled, and no anomalies were noted. 1.3 Completed STIS/CCD/MA1/MA2 8245 (Black Hole Accretion Outbursts in Soft X- Ray Transients) The Space Telescope Imaging Spectrograph (CCD, MA1 and MA2) was used to make observations of the optical and ultraviolet counterpart of a soft X-ray outburst region from a black hole accretion disk. A wavelength and a CCD flat calibration images were also taken. The observations were executed as scheduled, and no anomalies were noted. 1.4 Completed Two Sets of STIS/CCD 8408 (STIS CCD Dark Monitor C8) The Space Telescope Imaging Spectrograph (CCD) was used to make a CCD bias calibration observation. This is to monitor the darks for the STIS CCD. The observations were executed as scheduled, and no anomalies were reported. 1.5 Completed FGS 8468 (Calibrating FGS1R's Interferometric Response as a Function of Spectral Color) The Fine Guidance Sensor (FGS1R) was used to make observations of star SAO185689 and several other reference stars as part of calibrating FGS1R's interferometric response as a function of spectral color. The purpose of this proposal is to obtain reference transfer functions through various filters at the center positions of the field of view of the FGS1R. The observations were executed as scheduled, and no anomalies were noted. 1.6 Completed STIS/CCD 8409 (STIS CCD Bias Monitor C8) The Space Telescope Imaging Spectrograph (CCD) was used to make a CCD bias calibration observation. This is to monitor the bias in the 1x1, 1x2, 2x1, and 2x2 bin settings at gain=1, and 1x1 at gain = 4, to build up high-S/N superbiases and to track the evolution of hot columns. The observations were executed as scheduled, and no anomalies were reported. 1.7 Completed WF/PC-2 8151 (NGC 1866: A Critical Test of Stellar Evolution for Intermediate Mass Stars) The WF/PC-2 was used to make observations of LMC cluster NGC-1866 in order to help study the stellar evolution for intermediate mass stars. The cluster NGC 1866 contains at least 23 Cepheid variable stars. The observations were executed as scheduled, and no anomalies were noted. 1.8 Completed STIS/CCD 8549 (POMS Test Proposal: STIS non-scripted parallel proposal continuation III) The Space Telescope Imaging Spectrograph (CCD) was used to make high galactic latitude observations as part of a non-scripted POMS Test Proposal. The observations were completed as scheduled, and no problems were reported. 1.9 Completed WF/PC-2 8274 (A Size Survey of Cometary Nuclei) The WF/PC-2 was used to make observations of the comet Schuster as part of a size survey of cometary nuclei. This is part of a program to determine the basic physical properties of a large fraction of the population of short-period comets. As described in 2.1 and HSTAR 7321, the acquisition for this proposal defaulted to fine lock back-up on one FGS only, possibly affecting eight observations. Otherwise, the observations were completed as planned, and no further anomalies were reported. 1.10 Completed STIS/CCD 8422 (Imaging Sensitivity and PSF Library C8) The Space Telescope Imaging Spectrograph (CCD) was used to make Point Spread Function (PSF) observations using standard star HD38666. This program has several goals: {1} to improve the calibration of the on-axis imaging sensitivity of STIS; {2} to obtain high S/N observations stars {both saturated and unsaturated} for a PSF library, and {3} to obtain narrow-band observations of a star field to improve on the STIS PSF model. The observations were completed as scheduled, and no anomalies were reported. 2.0 FLIGHT OPERATIONS SUMMARY: 2.1 Guide Star Acquisitions: Scheduled Acquisitions: 8 Successful: 8 As documented in HSTAR 7321, the acquisition at 291/165317Z defaulted to fine lock back-up on FGS-2 only when the scan step limit was exceeded on FGS-1. The proposal detailed in 1.9 may have been affected. Scheduled Re-acquisitions: 6 Successful: 6 2.2 FHST Updates: Scheduled: 16 Successful: 16 2.3 Operations Notes: Using ROP SR-1, the SSR EDAC error counter was cleared twice. The NSSC-1 status buffer was dumped and reset at 292/0617Z as directed by ROP NS-3. 3.0 SIGNIFICANT FORTHCOMING EVENTS: Continuation of normal science observations and calibrations. /DMH