HUBBLE SPACE TELESCOPE DAILY REPORT #2174 PERIOD COVERED: 0000Z (UTC) 07/27/98 - 0000Z (UTC) 07/28/98 Daily Status Report as of 209/0000Z 1.0 ACTIVITIES SCHEDULED AND ACCOMPLISHED: 1.1 Completed NIC/1/2/3 7855 (The Evolution of Powerful Radio Galaxies) The Near Infrared Camera (Camera One, Two and Three) was used to make observations of the powerful radio galaxy 3C268.3. Our proposed NICMOS observations combined with our multi-wavelength observing program will finally provide us with the data we need to build a picture of how powerful radio galaxies evolve. The observations were completed as planned, and no problems were reported. 1.2 Completed Three Sets of STIS/CCD 7910 (STIS Extragalactic Parallel Survey) The Space Telescope Imaging Spectrograph (CCD) was used to make extragalactic slitless spectrographic observations as part of the parallel high galactic latitude survey to search for emission line galaxies. Data was taken in parallel, and are not subject to proprietary time. The observations were executed as scheduled, and no anomalies were noted. 1.3 Completed Four Sets of WF/PC-2 7909 (POMS Test Proposal: WF II Parallel Archive Proposal) The WF/PC-2 was used to make parallel observations as part of the POMS test proposal. This test proposal is designed to simulate scientific plans. The observations were completed as planned, and no problems were reported. 1.4 Completed Two Sets of STIS/CCD 7908 (POMS Test Proposal: STIS Non-Scripted Parallel Proposal) The Space Telescope Imaging Spectrograph (CCD) was used to make calibration observations as part of the POMS Test Proposal. This was a STIS non-scripted parallel proposal. The observations were completed as planned, and no problems were reported. 1.5 Completed WF/PC-2 6563 (The Helical Jet/ISM Interaction in NGC 4258) The WF/PC-2 was used to make observations of the helical jets on galaxy NGC-4258 and the interaction of the jets with the interstellar medium. NGC-4258 is a nearby active spiral with famous jets visible in radio continuum, visual emission lines, and soft x-rays. The observations were executed as scheduled, and no anomalies were noted. 1.6 Completed Two Sets of NIC/2/3 7907 (NICMOS Pure Parallel Winter 97-98) The Near Infrared Camera (Cameras Two and Three) was used to make pure parallel spectrographic observations of sky regions when another instrument is prime. The observations were completed as planned, and no anomalies were reported. 1.7 Completed Two Sets of WF/PC-2 7712 (WF/PC-2 Cycle 7 Supplemental Darks pt2/3) The WF/PC-2 was used to make a series of Cycle 7 supplemental calibration darks. 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 executed as scheduled, and no anomalies were noted. 1.8 Completed Two Sets of STIS/CCD 7948 (CCD Dark and Bias Monitor -- Cont. to Dec. 98) The Space Telescope Imaging Spectrograph (CCD) was used to measure CCD dark current and bias rates for the two supported amplifier settings {GAIN=1 and GAIN=4} in order to gather data for making superdarks and superbiases. The data will be used 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. 1.9 Completed Two Sets of STIS/CCD/NIC/1/2/3 7411 (Intergalactic Stars in the Virgo Cluster) The Space Telescope Imaging Spectrograph (CCD and NIC One, Two and Three) was used to make observations of the Virgo-Cluster looking for intergalactic stars. Using deep star counts from WF/PC-2 we have shown the existence of a population of intergalactic stars in the Virgo cluster. The observations were completed as scheduled, and no problems were reported. 1.10 Completed Three Sets of WF/PC-2 7620 (WF/PC-2 Cycle 7 Standard Darks) The WF/PC-2 was used to make a series of Cycle 7 standard dark calibration images. 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. 1.11 Completed Two Sets of STIS/CCD 7969 (STIS CCD G750L Fringe Flats at Intermediate MSM Positions) The Space Telescope Imaging Spectrograph (CCD) was used to investigate the flat-field fringing in the G750L grating at a number of wavelength settings. WAVECALs were also taken at the same gain and wavelength setting. The observations were completed as planned, and no anomalies were reported. 1.12 Completed Two Sets of STIS/CCD 7944 (STIS Sparse Field CTE Test) The Space Telescope Imaging Spectrograph (CCD) was used to conduct a STIS Sparse Field CTE test. The CTE measurements are made using the "sparse field test", along both the serial and parallel axes. The test was completed as scheduled, and no anomalies were noted. 1.13 Completed NIC/1/2/3 7886 (NICMOS Snap Shot Survey of Early-Type Galaxies) The Near Infrared Camera (Cameras One, Two and Three) was used to make observations of the early-type galaxy NGC-3056 as part of a snap-shot broad-band imaging survey. Since almost all early-type galaxies harbor dust, these images which are less sensitive to extinction and will provide superior light profiles for dynamical studies of the cores of these galaxies. The observations were completed as scheduled, and no problems were reported. 1.14 Completed NIC/1/2/3 7824 (Deep NIC Images of 20 High-Z Damped Ly-Alpha Galaxies) The Near Infrared Camera (Cameras One, Two and Three) was used to make observations of the high-Z damped Lyman-Alpha (DLA) galaxy PC0056+012. The HST imaging together with ground-based spectroscopy will unify absorption-line studies and faint galaxy imaging studies, providing a comprehensive picture of the history of assembly, star formation, gas consumption, and chemical enrichment in the DLA galaxies. The observations were completed as planned, and no problems were reported. 1.15 Completed Two Sets of STIS/CCD 8064 (POMS Test Proposal: STIS Non-Scripted Parallel Proposal - Backup) The Space Telescope Imaging Spectrograph (CCD) was used to conduct a non-scripted parallel POMS test. The observations were completed as scheduled, and no problems were reported. 1.16 Completed NIC/1/2 7849 (Metallicity and the Cepheid Distance Scale) The Near Infrared Camera (Cameras One and Two) was used to make observations of Cepheid variable stars in the NGC-925 galaxy. The local distance scale to galaxies is largely based on the Cepheid period-luminosity relation. Motivated by the goal of measuring an accurate value of the Hubble constant, HST has been used successfully to discover scores of Cepheid variables in each of about 20 galaxies. The observations were executed as scheduled, and no anomalies were noted. 1.17 Completed STIS/CCD 7912 (STIS Parallel Archive Proposal - Nearby Galaxies - Imaging and Spectroscopy) The Space Telescope Imaging Spectrograph (CCD) was used to make parallel observations of nearby galaxies. This survey will be useful to study the star formation histories, chemical evolution, and distances to these galaxies. These data will be placed immediately into the Hubble Data Archive. The observations were completed as scheduled, and no problems were reported. 1.18 Completed WF/PC-2 8059 (POMS Test Proposal: WF-2 Targeted Parallel Archive Proposal) The WF/PC-2 was used to make observations in parallel with the prime science observations. The parallel opportunities available with WF/PC-2 in the neighborhood of bright galaxies are treated in a slightly different way from the normal pure parallels. Local Group galaxies offer the opportunity for a closer look at young stellar populations. The observations were completed as planned, and no anomalies were reported. 2.0 FLIGHT OPERATIONS SUMMARY: 2.1 Guide Star Acquisitions: Scheduled Acquisitions : 7 Successful : 5 Scheduled Reacquisitions : 8 Successful : 7 The acquisitions at 209/0626Z and at 209/0712Z failed, as did a re-acquisition at 209/0512Z, due to the gyro 6 motor current jump detailed in 2.3. HSTAR 6598 was written for these occurrences. 2.2 FHST Updates: Scheduled : 18 Successful : 14 As documented in HSTAR 6598, updates at 209/0620Z, at 209/0624Z, at 209/0655Z and at 209/0658Z failed due to the gyro 6 motor current jump detailed in 2.3. 2.3 Operations Notes: Using ROP SR-1, the SSR EDAC error counter was cleared. A TTR was written for a recoverable SSAR data drop out at 209/0204Z. HSTAR 6596 describes a gyro 6 motor current jump and an associated motor current error flag which occurred at 209/050150Z. This resulted in gyro 6 being taken offline and an autonomous switch to a three-gyro (gyros 3, 1, and 5) configuration. Operationally, a Three Gyro High/Low Gyro Bias update was performed and uplinked at 209/0736Z, followed by an ARU/PRT at 209/0833Z to correct a four degree roll drift. The acquisition at 209/0917Z was successful and normal spacecraft and science operations resumed. During the approximate four-hour period when the take data flag remained down, science was interrupted. The proposals affected, all of which occurred during the period of the next report, were: part of an iteration and an entire iteration of STIS 8064 (POMS Test Proposal: STIS Non-Scripted Parallel Proposal - Backup), two iterations of NIC 7909 (POMS Test Proposal: WF II Parallel Archive Proposal), two iterations of STIS 7948 (CCD Dark and Bias Monitor -- Cont. to Dec. 98), WF/PC-2 7386 (A Snapshot Survey of Nova Shells), STIS/NIC 7565 (Comparison of Protoplanetary Disks), an iteration of WF/PC-2 7909 (POMS Test Proposal: WF II Parallel Archive Proposal), and most of STIS 7969 (STIS CCD G750L Fringe Flats at Intermediate MSM Positions). Due to the events described above, per ROP NS-6, FOC errors were reset at 209/0801Z. Also, at 209/0833Z, using ROP NS-12, STIS flight software errors were cleared. 3.0 SIGNIFICANT FORTHCOMING EVENTS: Continuation of normal science observations and calibrations. /DMH