FUSE Observer's Advisory Committee
Meeting Minutes No. 1
28 April 1999

The NASA Project Scientist for FUSE, George Sonneborn of the Goddard Space Flight Center, convened the first FUSE Observer's Advisory Committee (FOAC) meeting on Wednesday, 28 April 1999, at Johns Hopkins University (JHU) in Baltimore, Maryland. Attendees at the meeting included:

Committee members : Bregman, Chu, Deharveng, Federman, Guinan, Harper, Hutchings, Koratkar, Raymond, Wannier

NASA : Sonneborn

JHU : Andersson, Blair, Friedman, Massa, Moos, Murphy, Oegerle, Weaver

This document contains our notes from the first FOAC meeting. Each boldface heading below represents an area of significant discussion during the meeting.

Function of the FOAC

Sonneborn emphasized that the primary purpose of the FOAC is to advise NASA on matters related to the Guest Investigator (GI) program. He suggested that advice from the FOAC might be particularly helpful in the following areas:

  1. Implementation of the Cycle 1 GI program
  2. FUSE data products and analysis
  3. Cycle 2 NRA schedule and policies
  4. Cycle 1 GI data analysis budgets

Mission Status

Warren Moos welcomed the FOAC to JHU. He stressed that FUSE is different from many other NASA astronomy missions in that FUSE observing time during the three-year prime mission is divided approximately equally between the PI Team and Guest Investigators. The mission had a total cost cap for the development phase, so if something "new" was needed, something else had to be cut as there was no extra money available. The budget for the operations phase is also limited, but is not formally "capped" by NASA. He encouraged the FOAC to "push" for what it felt was important as that would help the Project to set priorities.

George Sonneborn said the FUSE launch date moved into June as a result of delays in the launch of a Delta III rocket that preceded the FUSE launch.

A program of Early Release Observations (ERO) is planned. These were prepared by the FUSE Science Team and will be executed at the end of the Science Verification phase and before the official start of normal science operations. The ERO data will be released through the FUSE archive web site several months after the observations. This will allow the scientists involved enough time to analyze the spectra and prepare results for publication.

Science Operations

JHU staff reviewed the status of mission planning and scheduling (Blair), the results of satellite thermal-vacuum testing and expected on-orbit performance (Friedman), and science data processing (Oegerle).

Mission Planning and Scheduling

The FOAC asked if a weekly (or periodic) list of planned observations could be posted on the web to give observers a chance to see when their observations would be executed. Andersson pointed out that the nature of the FUSE mission planning process makes it difficult to provide high-fidelity schedules on time scales of more than a few days. The FOAC acknowledged this and said that they were willing to accept that the observing schedule may change, but that a weekly listing of "targets nominally on the observing list" would still be useful. Blair said that the Mission Planning Team intends to make every effort to schedule observations with specific time requirements in the specified windows.

Data Processing and Analysis

Oegerle reviewed the calibration steps in the FUSE science data pipeline that leads from the raw 2D image to 1D extracted spectra. During the discussion, several FOAC members said that some intermediate data products (between the full 2D raw images and the fully extracted and summed 1D spectra) would be very important for understanding and interpreting FUSE spectra. There was discussion of how this information could be made available to the observer.

Two principal areas of concern were discussed: (1) how to identify and correct for detector features that get summed into the 1D spectrum, and (2) how to achieve maximum spectral resolution (for bright sources) when summing over the full height of the astigmatic spectrum smears the line spread function. One suggestion was that the corrected 2D detector image could be output (in addition to the 1D summed spectrum) in a number (3-9) of Y bins (across the dispersion). This is not possible with the current design of the FUSE science data pipeline. Another possibility would be to extract the spectra with different widths in the Y-direction (i.e., effectively only extracting the core of the astigmatic spread).

The science data pipeline is still incomplete, as it requires some flight data. The issues discussed at the FOAC will be considered in the long-term plans for the pipeline, and an update on its status will be provided at the next FOAC meeting.

FUSE Data Workshop

B-G Andersson presented the Project's intention to organize a data workshop for FUSE GIs in the late fall (tentatively November). The FOAC endorsed the idea and asked that the selection of the date for the meeting take into account the HST TAC schedule, holidays, etc.

It was noted that a data workshop would also benefit potential Cycle 2 proposers, whether or not they are also Cycle 1 observers (i. e., already selected as GIs).

FUSE GI Budgets

The FUSE GI budget appears to be fairly healthy. Award letters from NASA-HQ will be sent to US FUSE GIs this summer. Grants will initiated this fall, once FY2000 funds are available.

Cycle 2 Call for Proposals

The current schedule for Cycle 2 activities is:

  1. Release NRA : Nov-Dec 1999
  2. Proposals due : Mar 2000
  3. Proposal review : Apr-May 2000
  4. Selections announced : Jun 2000
  5. Phase 2 proposals due : Aug 2000
  6. Start Cycle 2 : Oct 2000


The FOAC discussed internal administration issues. Committee membership will be nominally for 2 years. Some of the initial membership may be asked to step aside after 1-1.5 years to permit the appointment of new members.

The FOAC felt that the first meeting had worked very well without a formal Chair and, thus, declined to elect one. George Sonneborn was asked to act as convener of future meetings, with the expectation that the FOAC will appoint individual members to specific tasks on a case-by-case basis (e.g., presentations to NASA HQ, etc.).


The next FOAC meeting will be held in the fall of 1999.

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