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Space Telescope Users Committee
September 1994

			   STUC REPORT (Sept. 1994) 
    
    The Space Telescope Users Committee met on September 8-9, 1994, at STScI.
    The STUC met jointly with the Servicing Science Working Group (SSWG)
    on the first day to review the project status, budget, and prospects
    for long-term operation of the spacecraft.  The second day was concerned
    largely with interaction of HST users with STScI.
    
    With regards to material presented jointly to the STUC and SSWG, we
    summarize as follows:
    
    1. The HST project manager presented a somber status report on flight
    spares for the 1997 refurbishment mission, as well as the long-term plans for
    developing advanced spare components (fine guidance sensors, batteries,
    solid-state data recorders, gyros, and so on) that would be required to
    ensure operation of HST over its full 15-year mission.
    The recent budget cuts applied to the project have essentially curtailed
    all work on second-generation flight spares, leaving the project with
    a small inventory of parts on hand to service any component failures that
    may occur prior to the 1997 mission.  The project also reported that
    additional 10% budget reductions have been requested from 1996 on.
    The project could not identify additional savings to be obtained
    without resorting to a number of options that the STUC considers to
    be extremely unattractive.  These include waiving the HST Level I
    requirements, terminating the Advanced Camera, reducing the data analysis
    money by greater than 50%, and so on.
    
    We find that at the very minimum, the HST project is not being allowed to plan
    sensibly for long-term support of the 15-year mission due to the projected
    shortage of money required to develop and support the hardware required.
    We are furthered concerned that if component failures on orbit continue as
    they have in the past, operation of the spacecraft more than a few years
    into the future may be at serious risk.  We further find this situation
    remarkable, given 1) the investment made to the program so far, 2) the
    success of the repair mission, 3) the demonstrated performance of the
    repaired telescope, all leading to 4) the keen interest of the public in
    the recent discoveries made by the repaired telescope.
    
    The STUC has the distinct impression that the perception still exists, both
    within NASA and without, that the HST budget can be further reduced
    without seriously jeopardizing the future scientific returns from HST.
    We are surprised by the persistence of this perception, given that none
    of the six reviews of the project budget conducted so far this
    year (one by the STUC itself) have been able to identify excess moneys
    or savings to be obtained that did not have an adverse effect on the
    operation of HST. 
    
    2. The STUC was briefed on the current plans to expand the role of the
    STScI in NASA's educational and public outreach activities and views the
    STScI role as an important way to disseminate to Congress, NASA, and the
    general public the remarkable scientific results now being obtained in
    spite of a dangerously tight budget.  The STUC is willing to contribute
    to this effort in any way that it can.
    
    3. The STUC commends the Project on restoring the Advanced Camera to the
    program and issuing an AO to which all qualified proposers may respond.
    However, we are concerned that at the level of funding envisaged, the
    resulting instrument may not be a significant advance over WFPC-II; in this
    case we feel that the question of proceeding with funding for the AC as
    opposed to other pressing HST needs should be carefully examined. We
    strongly support efforts to enlist funding support form other individual
    nations or groups to enhance the performance of the AC.  We note that the
    ``Frontiers of Space Imaging Study'' clearly identified the Advanced Camera
    as a means to enhance and ensure continued scientific returns over
    the lifetime of the HST mission, a point of view that we endorse.
    
    4. STIS and NIC remain on schedule and budget for the 1997 mission.
    The project clearly understands that withholding money from either
    instrument at this late stage will ultimately only result in delayed
    deployment of the instruments and larger long-term costs.  We understand
    that with modest effort, it may be possible to equip STIS with additional
    optical and UV filters.  This may be an attractive ``insurance'' option
    for providing some UV, or even optical imaging capability, should FOC or
    WFPC2 fail prior to deployment of the Advanced Camera.
    We encourage the project and STIS team to investigate this option.
    
    With regards to material presented solely to the STUC, we
    summarize as follows:
    
    1. The STUC was very impressed by both the execution and the high quality
    of the scientific data that came out of the HST observing campaign during 
    the impact of the fragments of comet Shoemaker-Levy 9 with Jupiter in July 
    1994.  We commend the STScI and all of the individuals involved.  Of 
    particular note was the organization beginning with the call for proposals, 
    through the mini-TAC review and selection, and the subsequent prompt funding 
    of investigators which ensured adequate planning and preparation.  
    This latter contributed not only to the high quality of the results but
    also to their prompt dissemination to both the public and the astronomical
    community.  This experience should provide a model for future HST
    observing campaigns.
    
    2. The STUC notes a minor breakdown in communications regarding the
    completion of on-orbit characterization and calibration of the scientific
    instruments following the successful repair mission.  In one particular
    example, GHRS side 1 data obtained through mid-summer 1994 were processed 
    in the pipeline using pre-repair mission theoretical sensitivity curves, yet
    users of this instrument were not directly notified when the on-orbit
    calibration files became available.  This information was duly placed in
    STEIS (dated July 20, 1994), but it is clear that the members of STUC (and
    probably most users) do not browse in STEIS unless notified of the need to
    do so, preferably by e-mail.  In general, we ask that STScI alert observers
    upon receipt of their observations of any outstanding calibration problems.
    
    3. We reviewed the plans for evaluating Cycle 5 proposals, and note that
    the number of panels has expanded from 6 to 8.  We note that the division
    of proposals into various categories, while necessary, is somewhat arbitrary
    and should not in any case be used as criteria for dividing telescope time
    among the various sub-fields of interest.  STScI has expressed its goal
    of encouraging the TAC to allocate time in an attempt to define the best
    science program overall, regardless of the mix of problems, and we encourage
    this approach.  We also commend STScI for changing the allocation from
    spacecraft time to orbits for Cycle 5, as well as for implementing greatly
    simplified proposal forms.
    
    4. We commend STScI for development of the PRESTO and POSS programs
    to assist observers with development of their Phase II proposals
    and reduction of observations once their observations have been obtained.
    We find it attractive to be able to interact with a small group of
    individuals for the wide variety of problems that may arise in the
    planning and reduction of observations.  We especially endorse having a
    responsible PhD level person (with associated support staff) as being
    THE contact for any given program.  At the same time, we strongly support
    the creation of a single database structure where the status of any proposal
    or problem is tracked by the system itself, rather than the memory or
    availability of any single person.  It is extremely important to ensure
    that programs do not ``fall through the cracks'' at any stage of their
    implementation.  Portions of this database should be available to the
    outside users, with due regard to the security of the individual GO proposal.
    
    A key aspect of the POSS approach is the analysis ``hotseat,'' which
    provides a constantly available and monitored point of contact to STScI.
    We recommend adoption of a hotseat phone or email contact by the PRESTO
    program, and all other STScI programs involving extensive contact
    or interaction with HST users.  We also urge that all such hotseat or
    general points of contact be clearly posted as an ongoing feature in each
    STScI Newsletter issue.
    
    5. The STUC is also concerned with having the best scientific advice
    available for preparation and analysis of the observations.
    In short, understanding what an observer is attempting to accomplish
    and forestalling problems will in many cases require interaction
    with STScI staff capable of understanding both the technical and
    scientific aims of the proposals.  We thus encourage involvement of the
    STScI research staff in both the PRESTO and POSS programs.
    
    6. We suggest that STScI clarify the definition and utility of dark-time
    (that is the portion of the orbit during which the spacecraft is within
    the earth's shadow) for programs that require the lowest backgrounds.
    This has become especially important now that users must fill entire orbits.
    We wish to know under what imaging and spectroscopy conditions dark-time
    should be requested, and suggest clear instructions be added to the
    Phase II handbooks.  Similarly, we recommend that STScI work with T. Ake
    from GSFC to implement a low particle background scheduling algorithm for
    those programs for which this is an important requirement, along with the
    relevant documentation and instructions.
    
    7. We were pleased to see that the STSDAS group continues to upgrade this
    software package in a time of decreasing man-power, and were pleased to see
    their cautious approach in converting (parts of) STSDAS to a C or C++
    environment, avoiding the many pitfalls that other observatories have
    encountered in similar transitions. We urge that the STSDAS group be able to
    continue their important work, as many HST users depend on this software
    package as their sole environment to reduce and analyze HST data.