Hubble Space Telescope Daily Report #2668 19-20 July 2000
HUBBLE SPACE TELESCOPE
DAILY REPORT #2668
PERIOD COVERED: 0000Z (UTC) 07/19/00 – 0000Z (UTC) 07/20/00
Daily Status Report as of 202/0000Z
1.0 OBSERVATIONS SCHEDULED AND ACCOMPLISHED:
1.1 Completed WF/PC-2 8632 (A UV Atlas of Nearby Galaxies)
The WF/PC-2 was used to perform a snapshot survey of local galaxies at UV wavelengths with the F300W filter. The aim of the project is to build a reference UV Atlas of normal galaxies, whose optical images are well known, with the highest possible degree of information, covering all the morphological types and luminosity classes. The proposal completed normally.
1.2 Completed Three Sets of STIS/CCD 8808 (POMS Test Proposal: STIS Non-Scripted Parallel Proposal Continuation III)
The Space Telescope Imaging Spectrograph (CCD) was used to make non-scripted, parallel observations as part of a POMS test proposal. The observations completed with no anomalous activity.
1.3 Completed STIS/CCD/MA1 8279 (Cataclysmic Variable Disk Winds: A High Time and Spectral Resolution Study of Flow Inhomogeneity)
The Space Telescope Imaging Spectrograph (CCD and MA1) was used to observe disks and disk winds that are found in many astrophysical settings. The proposal completed nominally.
1.4 Completed Two Sets of WF/PC-2 8544 (POMS Test Proposal: WFII Backup Parallel Archive Proposal II)
The WF/PC-2 was used to execute a POMS test proposal that was designed to simulate scientific plans. No problems were encountered.
1.5 Completed STIS/CCD 8437 (Dark Monitor-Part 2 C8)
The Space Telescope Imaging Spectrograph (CCD) was used to monitor the darks. The proposal completed nominally.
1.6 Completed Three Sets of STIS/MA1/MA2 8859 (MAMA Dispersion Solution Check)
The Space Telescope Imaging Spectrograph (MA1 and MA2) was used to determine wavelength dispersion solutions on a yearly basis as part of a long-term monitoring program. Deep engineering wavecals for each MAMA grating will be obtained. The pointing problems discussed in 2.3 occurred before the second iteration of this proposal, and all observations in that iteration and the final one were lost. Otherwise, the observations completed nominally with no further problems.
1.7 Completed WF/PC-2 8220 (Galaxy M/L Ratios, the Morphology-Density Relation, and Weak Lensing in the z=0.93 Cluster of 3C336)
The WF/PC-2 was used to obtain deep mosaic images for the radio selected cluster around 3C336 at z=0.93. This proposal is the last part of a program to take large HST WFPC2 mosaics of distant clusters. We augment the HST mosaics of the clusters with extensive ground-based spectroscopy and imaging from the Keck, MMT, ESO-VLT, NTT, and WHT telescopes. The observations completed, and there were no reported problems.
1.8 Completed Four Sets of STIS/CCD 8260 (Searching for the Hydrogen Reionization Edge of the Universe at 5HST)
The Space Telescope Imaging Spectrograph (CCD) was used to observe one of 36 parallel orbits {4–5 fields of 5–8 orbits each} to constrain the H Lyman-edge in emission that marks the transition from a neutral to a fully ionized IGM at a predicted zion~eq5–15. This edge is due to recombination from the H Lyman series and Lyman continuum, and can be used to constrain zion, one of the most important unknown quantities in large scale structure and cosmology. The pointing problems discussed in 2.3 occurred during the second iteration of this proposal, partially affecting that iteration. It was not solved until after the forth iteration, so the third and fourth iterations were completely lost. Otherwise, the proposal completed nominally with no further problems..
1.9 Completed Two Sets of WF/PC-2 8445 (WF/PC-2 Cycle 8 Earth Flats)
The WF/PC-2 was used to make Cycle 8 Earth flat calibration observations. This is to obtain sequences of earth streak flats to construct high quality flat fields for the WF/PC-2 filter set. . The pointing problems discussed in 2.3 occurred before the second iteration of this proposal, and all observations in that iteration were
lost. Otherwise, the observations were executed as scheduled, and no further anomalies were noted.
1.10 Completed WF/PC-2 8599 (A Census of Nuclear Star Clusters in Late-Type Spiral Galaxies)
The WF/PC-2 was used to conduct an I-band snapshot survey of a well-defined sample of nearby, face-on spiral galaxies of type Scd or later. The proposal completed nominally.
1.11 Completed STIS/CCD 8236 (Black Holes and Gas Disks in a Complete Sample of Radio-Loud Ellipticals – II: Kinematics)
The Space Telescope Imaging Spectrograph (CCD) was used to make observations of the radio-loud elliptical galaxy UGC-12064. From these observations we will measure the black hole masses, determine the nature, kinematics, and structure of the central gas disks and obtain a modeled upper limit to their mass accretion rates. A wavelength calibration image was also taken. The observations were completed as planned, and no problems were reported.
1.12 Completed WF/PC-2 8805 (POMS Test Proposal: WFII Parallel Archive Proposal Continuation)
The WF/PC-2 was used to perform a generic target version of the WFPC2 Archival Pure Parallel program. The program will be used to take parallel images of random areas of the sky, following the recommendations of the Parallels Working. The proposal completed with no reported problems.
1.13 Completed WF/PC-2 8110 (Supernova Remnants in a Cloudy Interstellar Medium)
The WF/PC-2 was used to observe small cloudlets in the interstellar medium {ISM} that may have a marked effect on the physical structure and evolution of supernova remnants {SNRs}. These WF/PC-2 images can be combined with complementary observations in other wavelength regimes to identify cloudlets inside remnants, trace SNR shock fronts, determine the physical parameters of interior cloudlets and compare them to those of the hot interior, and investigate the evaporation of shocked cloudlets into the hot cavities of the SNRs. There were no reported problems.
1.14 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.
2.0 FLIGHT OPERATIONS SUMMARY:
2.1 Guide Star Acquisitions:
Scheduled Acquisitions: 6
Successful: 6
Scheduled Re-acquisitions: 10
Successful: 6
See 2.3 for an explanation of the four re-acquisition failures (at 201/1311Z, 201/1414Z, 201/1623Z, and 201/1800Z).
2.2 FHST Updates:
Scheduled: 11
Successful: 11
2.3 Operations Notes:
Using ROP SR-1A, the SSR EDAC error counter was cleared twice.
The engineering status buffer limits were adjusted three times per ROP DF-18A.
Flight software (FSW) 1.3A RAM installation was performed on HST between 210/121000Z and 210/124000Z. A post-installation regression indicated nominal performance. The subsequent re-acquisition at 210/131100Z failed when the search radius limit was exceeded. Real-time maps showed a large attitude error. Further analysis indicated that the FSW installation overwrote the RGA alignment tables containing the Gyro 6 "shadow" mode and the related biases. The installed FSW had contained the previous alignments and biases with Gyro 6 in the control loop. This caused the attitude error. After several false starts due to commanding problems when TDRS-E events were removed from the schedule (HSTARs 7735 and 7736 as well as a TTR), the correct FSW-related tables were re-uplinked at 210/1448Z, and additional maps and a successful ARU/PRT were performed at 201/1815Z. The following re-acquisition successfully achieved fine lock. Additional table and software dumps confirmed that the FSW was properly configured and operating nominally. Most of these events are captured in HSTAR 7734. Proposals affected are described in 1.6, 1.8 and 1.9.
During the EPS checkout following the FSW installation, SEs discovered that the impedance induced by the Power Control Unit (PCU) fault had appeared at approximately 20 mohms. Data extractions indicate that the impedance between batteries 5 and 6 were at 0 mohms through the orbit night period ending at 197/2154Z. A shift of approximately 5 mohms was first observed at entry to orbit night at 197/2255Z. The impedance gradually increased over the following two days to the current level of about 20 mohms. EPS will continue to monitor the system closely to characterize system performance under software charge control with the PCU fault.
The battery pressure test limits were updated at 201/1940Z per an operations request.
The VTFE curves were adjusted at 201/2121Z as directed by an operations request.
Per ROP IC-2, SSA transmitter 2 was turned on and off at 201/2257Z.
Real-time operation transitioned to the CCS "C" string at 202/0305Z when the "B" string stopped updating at 202/0235Z (HSTAR 7737). "B" string was again configured as prime at 202/0716Z.
Using ROP NS-03, the NSSC-1 status buffer was dumped and reset at 202/0615Z.
3.0 SIGNIFICANT FORTHCOMING EVENTS:
Continuation of normal science observations and calibrations.
