NASA Hubble Space Telescope Daily Report #4693

HUBBLE SPACE TELESCOPE DAILY REPORT #4693

Continuing to collect World Class Science

PERIOD COVERED: 5am September 10 – 5am September 11, 2008 (DOY 254/0900z-255/0900z)

OBSERVATIONS SCHEDULED

FGS 11212

Filling the Period Gap for Massive Binaries

The current census of binaries among the massive O-type stars is seriously incomplete for systems in the period range from years to millennia because the radial velocity variations are too small and the angular separations too close for easy detection. Here we propose to discover binaries in this observational gap through a Faint Guidance Sensor SNAP survey of relatively bright targets listed in the Galactic O Star Catalog. Our primary goal is to determine the binary frequency among those in the cluster/association, field, and runaway groups. The results will help us assess the role of binaries in massive star formation and in the processes that lead to the ejection of massive stars from their natal clusters. The program will also lead to the identification of new, close binaries that will be targets of long term spectroscopic and high angular resolution observations to determine their masses and distances. The results will also be important for the interpretation of the spectra of suspected and newly identified binary and multiple systems.

FGS 11819

Certifying the SMOV4 FGS AMA Stars with FGS1r

This proposal observes the candidate SMOV4 “AMA stars” prior to SM4 to certify which of them are unresolved point sources, and hence is an appropriate AMA target. Each target is to be observed in a 1-orbit visit using FGS1r in its highly angular resolution Transfer mode with two exposures. Exposure 1 utilizes a 0.8″ scan path with 20 scans which will provide high S/N for the detection of binary down to ~12 mas, while the second exposure utilizes a 6″ scan path to provide sensitivity to putative wide companions.

FGS 11842

Long Term Stability of FGS1r in Position Mode

It is known from our experience with FGS3, and later with FGS1r, that an FGS on orbit experiences long term evolution, presumably due to disorption of water from the instrument’s graphite epoxy composits. This manifests principally as a change in the plate scale and secondarily as a change in the geometric distortions. These effects are well modeled by adjustments to the rhoA and kA parameters which are used to transform the star selector servo angles into FGS (x, y) detector space coordinates. By observing the relative positions of selected stars in a standard cluster at a fixed telescope pointing and orientation, the evolution of rhoA and kA can be monitored and calibrated to preserve the astrometric performance of FGS1r.

NIC1/NIC2/NIC3 11820

NICMOS Post-SAA Calibration – CR Persistence Part 7

Internals for CR persistence

NIC2 11548

NICMOS Imaging of Protostars in the Orion A Cloud: The Role of Environment in Star Formation

We propose NICMOS observations of a sample of 252 protostars identified in the Orion A cloud with the Spitzer Space Telescope. These observations will image the scattered light escaping the protostellar envelopes, providing information on the shapes of outflow cavities, the inclinations of the protostars, and the overall morphologies of the envelopes. In addition, we ask for Spitzer time to obtain 55-95 micron spectra of 75 of the protostars. Combining these new data with existing 3.6 to 70 micron photometry and forthcoming 5-40 micron spectra measured with the Spitzer Space Telescope, we will determine the physical properties of the protostars such as envelope density, luminosity, infall rate, and outflow cavity opening angle. By examining how these properties vary with stellar density (i.e. clusters vs groups vs isolation) and the properties of the surrounding molecular cloud; we can directly measure how the surrounding environment influences protostellar evolution, and consequently, the formation of stars and planetary systems. Ultimately, this data will guide the development of a theory of protostellar evolution.

WFPC2 10884

The Dynamical Structure of Ellipticals in the Coma and Abell 262 Clusters

We propose to obtain images of 13 relatively luminous early type galaxies in the Coma cluster and Abell 262 for which we have already collected ground based major and minor axis spectra and images. The higher resolution HST images will enable us to study the central regions of these galaxies which is crucial to our dynamical modelling. The complete data set will allow us to perform a full dynamical analysis and to derive the dark matter content and distribution, the stellar orbital structure, and the stellar population properties of these objects, probing the predictions of galaxy formation models. The dynamical analysis will be performed using an up-to- date axi-symmetric orbit superposition code.

WFPC2 11113

Binaries in the Kuiper Belt: Probes of Solar System Formation and Evolution

The discovery of binaries in the Kuiper Belt and related small body populations is powering a revolutionary step forward in the study of this remote region. Three quarters of the known binaries in the Kuiper Belt have been discovered with HST, most by our snapshot surveys. The statistics derived from this work are beginning to yield surprising and unexpected results. We have found a strong concentration of binaries among low-inclination Classicals, a possible size cutoff to binaries among the Centaurs, an apparent preference for nearly equal mass binaries, and a strong increase in the number of binaries at small separations. We propose to continue this successful program in Cycle 16; we expect to discover at least 13 new binary systems, targeted to subgroups where these discoveries can have the greatest impact.

WFPC2 11156

Monitoring Active Atmospheres on Uranus and Neptune

We propose Snapshot observations of Uranus and Neptune to monitor changes in their atmospheres on time scales of weeks and months. Uranus equinox is only months away, in December 2007. Hubble Space Telescope observations during the past several years {Hammel et al. 2005, Icarus 175, 284 and references therein} have revealed strongly wavelength- dependent latitudinal structure, the presence of numerous visible-wavelength cloud features in the northern hemisphere, at least one very long-lived discrete cloud in the southern hemisphere, and in 2006 the first dark spot ever seen on Uranus. Long-term ground-based observations {Lockwood and Jerzekiewicz, 2006, Icarus 180, 442; Hammel and Lockwood 2007, Icarus 186, 291} reveal seasonal brightness changes whose origins are not well understood. Recent near- IR images of Neptune obtained using adaptive optics on the Keck Telescope, together with HST observations {Sromovsky et al. 2003, Icarus 163, 256 and references therein} which include previous Snapshot programs {GO 8634, 10170, 10534} show a general increase in activity at south temperate latitudes until 2004, when Neptune returned to a rather Voyager-like appearance. Further Snapshot observations of these two dynamic planets will elucidate the nature of long-term changes in their zonal atmospheric bands and clarify the processes of formation, evolution, and dissipation of discrete albedo features.

FLIGHT OPERATIONS SUMMARY:

Significant Spacecraft Anomalies: (The following are preliminary reports of potential non-nominal performance that will be investigated.)

HSTARS:

11480 ACS Checksum mismatch during JV0027 installation @ 254/18:00z

During installation of ACS FSW JV0027 (CS5.11 ASIC 3.1A) the checksum mismatched during step 8 of OPS Request 18265. It was expected that JLSTCKSM =’abcd’x, but read back ‘abcc’x.

11481 WFPC status buffer message 290 @ 254/19:27:01z Parameter = 62012, time = 1767, received after SMS started.

11482 WFPC status buffer message 290 @ 254/19:39:11z Parameter = 64051, time = 7607, received after SMS started.

11483 NCC (NICMOS CRYO-COOLER) SAFED @255/7:57:45z Status Buffer Message

EXEC=908, Parameter=128(Octal) was received. The action request byte from the 8051 in operate mode had the bit set to safe the NCC.

COMPLETED OPS REQUEST:

• 18262-1 NSSC-1 FSW b18.6.5 Installation @ 254/16:26z
• 18259-1 ESM FSW 7.0.0 Installation @ 254/18:24z
• 18269-0 Turn OFF WFPC-II Replacement Heater @ 254/21:03z
• 18267-1 CONTINGENCY NCS CPL Reservoir Setpoint Change @ 254/21:06z
• 18270-0 Update t_min and t_setpt for NCS CPL @ 254/21:55z
• 18271-0 Set up NSSC Memory Monitor @ 254/22:17z
• 18272-0 Safe WF-2 @ 254/23:43z
• 18267-2 CONTINGENCY NCS CPL Reservoir Setpoint Change @ 255/00:03z
• 18264-2 WF/PC-II RAM Dump and Compare (ROP NS-16) @ 255/00:35z
• 18266-1 Update WFPC-II POM position in SHP after NSSC 8.6.5 FSW
• Installation @ 255/00:48z18265-0 ACS JV0027 EEPROM Installation @ 255/05:52z
• 18260-3 NCS Recovery and Cooldown @ 255/06:53z
• 18273-0 Turn On NCS CPL Startup Heater 255/08:33:52z

COMPLETED OPS NOTES: None

                          SCHEDULED     SUCCESSFUL

FGS GSacq                 11                 11
FGS REacq                 03                 03
OBAD with Maneuver        27                 27

SIGNIFICANT EVENTS:

QUEEN loaded and NCS Safed

Steps 4 through 31 of Ops Request 18262 were successfully executed to load QUEEN and safe the NICMOS Cooling System. The Queen FSW was loaded and dumped. The FSW team verified the contents. The NCC was transitioned down and the cooling system was safed. There were no concerns or issues in the NCC transition or safing. Queen was started and operated nominally.

NSSC-1 BL 8.6.5 Loaded/Activated

Ops Request 18262 was completed at 16:26 UTC. NSSC-1 BL 8.6.5 processing was activated at 16:06 UTC. ESM 7.0 installation will proceed immediately via Ops Request 18259, ~ 2? hours AHEAD of schedule.

ESM FSW Loaded

Ops Request 18259 was successfully executed to load and verify the ESM 8051 Flight Software, version 7.0.0. The ESM is currently in Operate and performing nominally. The 254 SMS was loaded and the pointer was set in preparation of SMS intercept. WFPC-2 Recovery will begin viaSMS at 19:20z. The CPL startup will begin shortly, followed by the ACS FSW load.

WFPCII SMS Recovery and NCS restart

status buffer error messages were received while WFPC2 was being recovered from the planned safemode following a successful NSSC-I FSW installation. At GMT 254/19:27:00 WFPC-II status buffer message 290 was reported with parameter 26510(dec). The error indicated the temperature of the AFM was lower than what the stored commanding was expecting, resulting in the AFM RTCS exiting prematurely. The likely cause of this error was an incorrect temperature range utilized in the stored program commands. At GMT 254/19:39 a second WFPC-II status buffer message 290 with parameter 26665(dec) was reported. This error indicated that the WFPC-II microprocessor checksum failed during execution of UIDLE. Following a meeting with Project management, WFPC-II was placed into safe mode via OPS Request 18272 to prevent further stored program commanding of the instrument. ACS FSW installation and NCS cool down are not affected and are proceeding ahead of schedule. The NCS compressor was turned on at ~255:01:28. As of 255/03:12:00, the NCS was returned to its nominal PID Operate state, beginning the NICMOS/NCS cooldown to the operational setpoint of 72.39 K in earnest. The system transitioned to the Surge state, where the Compressor maximum speed is limited to 7043 rps. The system remained in Surge until the Turboalternator inlet temperature fell below the 82 K level from its current reading of 103.4 K. At that point, full authority was granted to the PID Control Law to ramp the Compressor to its maximum allowed speed of 7330 rps. With the ramping down of the Compressor for the NCS shutdown beginning at roughly 254/13:16, the total down time for the NCS during the NSSC-1 and ESM installations was just short of 14 hours total.

NCS Safing.

At 255/07:57:45, the NCC Safed, due to a speed violation on the Circulator as reported by DT 120. The CPL continues to operate.

ACS FSW JV0027 (CS 5.11, ASIC 3.1A) Successfully Installed

ACS FSW JV0027 was successfully installed via OR#18265 at 255/05:51 GMT. A memory dump was performed and verified by Payload FSW. The instrument was transitioned to Operate Mode. No problems were observed. ACS was commanded to Safe mode to intercept the recovery SMS at 255/11:00 GMT.