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Space Telescope Users Committee
November 1998

The Space Telescope Users Committee (STUC) met in open session on 9-10 November 1998, in the Board Room of the Space Telescope Science Institute. Committee members in attendence were: B. Balick, J. Bally, J. Clarke, R. Fosbury, J. Frogel, L. Kay, P. McCarthy, F. Mirabel, S. Ortolani, S. Terebey, R. Thompson, F. Walter (Chair), H. Weaver, and B. Woodgate. R. Schulte-Ladbeck was absent.

Minutes of the meeting are reported elsewhere.

Readers should note that this report is based on information presented to the STUC in November 1998, and may be superceded by later developments. Readers are urged to refer to the STScI web pages for up-to-date information. Background material is available through the minutes.

Executive Summary

This meeting of the STUC occurred at a relatively tranquil time. The spacecraft is operating well, and the main concerns are with the future. Operating costs for the HST are projected to decrease by about 30% by the year 2010. The STScI is beginning a serious examine of its operations, and this will have some effect upon the users. The SM4 instrument WFC-3, which was envisioned to be a backup camera, has attracted some attention. There are moves afoot to add an IR channel, which will increase its scientific capabilities. However, the source of funding for any additions to the baseline instrument is yet to be identified. Closer to our time, NICMOS is about to run out of cryogen, and the decision on whether or not to fly the NCS will be made in the next few months.

New Director

The STUC welcomes the new director, Steve Beckwith. We look forward to working with him in our capacity as representatives of the users of the HST, to maximize the scientific return of the HST while maintaining acceptable levels of user support.

HST Scheduling

The STUC applauds the efforts of the STScI scheduling team, lead by Peggy Stanley, to clear up the backlog of cycle 4 and 5 proposals and to achieve the mandated level of NICMOS science. They have succeeded in this demanding task while keeping the observing efficiency of the HST high.


The STUC applauds the direct approach the STScI is taking with respect to "Cheap-Ops", and looks forward to working closely with the Director's office to identify ways to decrease operating costs. It is in everyone's interests to reduce costs in such a way as to minimize direct impacts on the users of the HST.

The User Survey

The STUC applauds the User Support Assessment Group for its User Survey, and thanks all users who responded. As the available resources decrease, it is inevitable that some user support will be affected, and the best way to determine those cuts which will hurt the least is to ask the users. We further thank those users who have volunteered to serve on the focus groups.

Community Parallels

The committee is pleased to see the high level of use of the community parallel data, and urges that the program be continued.

Moving Target Issues

The STUC strongly supports the STScI's plan to produce finder charts for Moving Target observations in time to support Cycle 8 Solar System programs, if not earlier. The STUC encourages the STScI to continue its investigation of the problem of the large pixel shifts seen in adjacent STIS images, and to implement corrective action if analysis identifies a feasible solution.

NICMOS Calibration

The shortened lifetime of NICMOS posed a significant challenge, to which the Institute responded capably and successfully. STScI has achieved its goal of maximizing science data taken with NICMOS and provided rapid preliminary calibration and distribution of pipleline software CALNICA and CALNICB.

However the STUC has a serious concern with the slow progress made on NICMOS calibration and characterization during the past year. The situation remains essentially unchanged from that of the September 1997 HST Calibration Workshop. Results of the recent User Survey show a high level of dissatisfaction with NICMOS calibration.

NICMOS is the first near-infrared instrument for STScI, and represents an important opportunity to develop in-house NIR expertise as well as to demonstrate to the astronomical community that STScI will capably handle its transition to NGST.

Given budget and staffing realities this may be the time to consider a more flexible approach to NICMOS support. The pipeline paradigm does not easily accomodate the interactive approach that NICMOS users have found necessary to reduce their data.

To improve accessibility to a wider range of users and improve the scientific return of NICMOS data, enough information should be provided with the standard data products so that capable observers without NIR experience can diagnose problems and identify proven solutions. To achieve this goal we encourage STScI to mine the knowledge and existing software of the NICMOS Instrument Team as well as experienced NICMOS users.

The WFC-3

STUC strongly supports the stretch concept of extending the wavelength range of WFC-3 to 1.9 microns by the addition of a near-IR channel. This concept would provide major and exciting new scientific opportunities for the 2nd decade of HST observations. In addition, such a near-IR capability would be a valuable link to and complement for observations with NGST. It will also provide an important complement to SIRTF observations. We recognize that the window of opportunity for initiating this stretch concept is narrow and urge that engineering development studies procede with all due haste. We look forward to working with STScI and the HST project to develop innovative ways to begin funding this stretch concept.

The inclusion of a near-IR channel on WFC-3 must not compromise the baseline UV/optical camera, and must not delay the scheduled launch of the SM4 mission.

The STUC has created a subcommittee, consisting of B. Balick, J. Frogel, P. McCarthy, and S. Terebey, to investigate the scientific case for the IR channel, and to examine ways of funding this option. The subcommittee shall report its findings and recommendations to STUC for further action.

The STUC strongly recommends that the HST project appoint a prominent and influential scientist to be scientific advocate for the IR channel on the WFC-3.

The Hubble Fellowship Program

The Hubble Fellowship is an extremely successful program, whose success can be measured by the number of imitative fellowship programs that now exist. However, the committee suggests that there are too many Hubble Fellowships being awarded each year. With 45 Hubble fellows at any one time, the fellowship is not as prestigious as it once was. The STUC recommends that the STScI and the HST project reduce the number of Hubble fellows to no more than 10 per year.

The STUC is extremely hesitant to recommend decreases in GO support, without assurance that these funds will revert to the user community. We recommend that all savings made by reducing the number of Hubble Fellows be returned to the user community, either by increasing the pools of funds available for GO use, or by earmarking these funds to support development of the WFC-3 IR-stretch concept.

This report submitted by Frederick M. Walter on behalf of the Space Telescope Users Committee February 1998