HUBBLE SPACE TELESCOPE DAILY REPORT #2342 PERIOD COVERED: 0000Z (UTC) 04/01/99 - 0000Z (UTC) 04/02/99 Daily Status Report as of 092/0000Z 1.0 ACTIVITIES SCHEDULED AND ACCOMPLISHED: 1.1 Completed Two Sets of STIS/CCD 7949 (CCD Dark and Bias Monitor -- Cont. to June 99) The Space Telescope Imaging Spectrograph (CCD) was used to conduct a CCD dark calibration and a bias monitoring program. It was also scheduled to track the growth of hot pixels on the CCD in general and within the various target acquisition apertures specifically. The observations were executed as scheduled, and no anomalies were noted. 1.2 Completed Two Sets of WF/PC-2 7713 (WF/P-2 Cycle 7 Supplemental Darks pt3/3) The WF/PC-2 was used to make supplemental dark calibration images. This dark calibration program obtains 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 anomalies were noted. 1.3 Completed WF/PC-2/STIS/CCD 7615 (Determination of the Mass Function of a Globular Cluster Through Gravitational Microlensing) The WF/PC-2 and the Space Telescope Imaging Spectrograph (CCD) were used to make gravitational microlensing observations of the large globular cluster NGC-6656 located in Sagittarius in order to study its mass function. Gravitational microlensing offers a unique and direct method of determining the masses of stars and other compact objects down to planetary masses. A bias and dark calibration observations were also taken. The observations were completed as planned, and no problems were reported. 1.4 Completed FOC/96 6349 (Snapshot Search for High Redshift QSOs with Far-UV Flux) The Faint Object Camera (f/96) was used to make snapshot images of the quasi-stellar object Q1358+115. This is to determine if this high redshifted object has a far ultraviolet flux. The observations were executed as scheduled, and no anomalies were noted. 1.5 Completed WF/PC-2 7622 (WF/PC-2 Cycle 7 Internal Monitor) The WF/PC-2 was used to make a set of Cycle 7 internal monitoring calibration measurements. A variety of internal exposures are obtained in order to provide a monitor of the integrity of the CCD camera electronics in both bays {gain 7 and gain 15}, a test for quantum efficiency in the CCDs, and a monitor for possible buildup of contaminants on the CCD windows. A bias calibration and an internal flat calibration image were also taken. The observations were executed as scheduled, and no anomalies were noted. 1.6 Completed Two Sets of STIS/CCD/MA1 7432 (Morphological and Spectral Evolution of Galaxies) The Space Telescope Imaging Spectrograph (CCD and MA1) was used to make observations to study the morphological and spectral evolution of the galaxy 3C348-1. A library of ultraviolet images of normal galaxies at low redshifts is essential to our understanding of the properties and evolution of the high redshift universe. The observations were completed as planned, and no problems were reported. 1.7 Completed Six Sets of WF/PC-2 8090 (POMS Test Proposal: WF-II Parallel Archive Proposal Continuation) The WF/PC-2 was used in the parallel mode to make some low galactic latitude archive observations. The program will be used to take parallel images of random areas of the sky. The observations were executed as scheduled, and no anomalies were noted. 1.8 Completed Four Sets of WF/PC-2 8053 (WF/PC-2 Cycle-7 Earth Flats -- Part II) The WF/PC-2 was used to take Earth flat calibration images. This proposal obtains sequences of Earth streak flats to construct high quality flat fields for the WF/PC-2 filter set. The observations were executed as scheduled, and no anomalies were noted. 1.9 Completed WF/PC-2 6572 (Searching for Low Mass Stars: the Mass Function at the H Burning Limit) The WF/PC-2 was used to make observations of the very low mass (VLM) stars in globular cluster NGC-6496. A thorough intercomparison of the luminosity and mass functions of several different clusters will provide useful tests on VLM stars evolution. These data will deliver the long awaited hints on the origin of the dark matter, and they will improve the understanding of the dynamical processes at work in globular clusters. The observations were executed as scheduled, and no anomalies were noted. 1.10 Completed Four Sets of STIS/CCD 8091 (POMS Test Proposal: STIS Non-Scripted Parallel Proposal Continuation) The Space Telescope Imaging Spectrograph (CCD) was used to make high galactic latitude, non-scripted, parallel observations. The observations were completed as planned, and no anomalies were noted. 1.11 Completed FOC/96 6713 (Geometric Measurement of Galaxy Distance) The Faint Object Camera (f/96) was used to make observations of supernova remnant SN1991T in order to make a distance calibration for the galaxy in which it is located. The supernova is being used as a powerful new geometric method for the determination of a galaxy's distance, by obtaining high spatial resolution imaging polarization of the candidate supernova light echoes. The observations were completed as planned, and no anomalies were reported. 2.0 FLIGHT OPERATIONS SUMMARY 2.1 Guide Star Acquisitions: Scheduled Acquisitions : 3 Successful : 3 Scheduled Reacquisitions : 11 Successful : 11 2.2 FHST Updates: Scheduled : 8 Successful : 6 As presented in HSTAR 7082, the full maneuver updates scheduled for 092/055959Z and 092/060244Z failed while using both trackers 1 and 2. The subsequent acquisiton, however, was successful. 2.3 Operations Notes: Using ROP SR-1, the SSR EDAC error counter was cleared three times. Realtime spacecraft operations transferred to the SAMS back-up facility yesterday afternoon. Operations personnel will remain in that location until the completion of the SM-3A SMGT SR2 dry run, scheduled to be completed late this afternoon/. The NSSC-1 status buffer was dumped at 091/1734Z per ROP NS-3. 3.0 SIGNIFICANT FORTHCOMING EVENTS: Continuation of normal science observations and calibrations. /DMH