FUSE Observer's Advisory Committee
Minutes for Meeting No. 11
2004 November 2-3, IAP, Paris


FOAC: Michael Crenshaw, Andrea Dupree, Cynthia Froning, Graham Harper, Jay Holberg, Alain Lecavelier des Estangs, Jason Prochaska, Evan Skillman, and Nicole St-Louis

(not present) Ed Fitzpatrick, Sumner Starrfield, and Ken Sembach

FUSE Team: Warren Moos, William Blair, Mary Beth Kaiser, B-G Andersson

Agencies: George Sonneborn (NASA), Alfred Vidal-Madjar (CNES)

Welcoming Remarks: Alfred Vidal-Madjar welcomed the members of the FOAC to their first meeting in France on behalf of the CNES. He also announced that CNES will be sending a new person to work on FUSE mission operations and data management at JHU. The FOAC welcomed this contribution and drafted a statement of support for CNES efforts in this area.

New FOAC members Michael Crenshaw and Edward Fitzpatrick (not present) were welcomed. This was Graham Harper's last meeting. His valued service on the committee and his active chairmanship of the FOAC were acknowledged.

Observatory Status - Blair (JHU) The overall efficiency of the mission remained high during the first half of Cycle 5, although there was some decline in the efficiency of scheduling science observations due to the need to include more constrained observations which had been carried over from earlier cycles. This did, however, result in a substantial clearing of these hold over observations. It was estimated that approximately 1.8 Ms of observing time will be carried over into Cycle 6.

These was a safeing event in June that resulted in the closure of the aperture doors, no subsequent impact on instrument performance was noted. The high voltage was raised on SiC 2A on July 20, 2004. In August a substantial increase in the noise level of the side B pitch gyro was noted. This noise, which showed a strong exponential-like temporal increase, resulted in a marked increase in pointing jitter. On September 28, the decision was made to switch to 1 Gyro mode. This resolved the pointing jitter and the spacecraft will operate in 1 the Gyro mode for the foreseeable future. Observing efficiency in 1-gyeo mode is not noticeably different from 2-gyro mode.

Instrumental sensitivities, which had been declining during the first three years of the mission, have apparently leveled off, particularly in the LiF channels.

A switch from LWRS aperture to MDRS aperture as the default aperture for bright targets (histogram mode) observations was implemented in July. Science requirements of existing programs were reviewed and programs with bona fide requirements for SiC coverage had their requested time doubled.

Projections of improved sky coverage advertised in Cycle 6 are meeting expectations.

CALFuse v3.0.7 was released in August and the delivery of v3.0 processed data to MAST was begun in September of 2004.

Jean-Micheal Desert of IAP reported on data archiving activities at IAP and recent improvements to the FUSE database and the ability to link to other data sets and resources.

Response to the Senior Review - Sonneborn

The 2004 Senior Review recommended that the FUSE mission be continued through FY08, along with planning for a possible close out of the mission in FY09. The FUSE project's response is summarized below.

  1. The mission can maintain full scientific capabilities and productivity, as well as adequate levels of GI support, into FY05 and FY06.
  2. The recommended funding levels for FY07 and FY08 will necessitate some reduction in FUSE capabilities and productivity. However, the mission's ability to pursue forefront scientific problems will not be compromised.
  3. GI funding levels will be maintained at a level commensurate with the mission's capabilities and productivity.
  4. FY07 funding guidelines can be met through planned staff reductions and automation of mission activities.
  5. FY08 funding guidelines can be met through elimination and consolidation of management activities.
  6. Plans for FY07-08 operations will be submitted to SR 2006.
  7. The mission will have to be higher risks accepted in spacecraft operations and observational planning.
  8. As a result, there may be increased observational inefficiency and lower data volume.

The FOAC discussed these and related issues which will inevidividly arise from budget restrictions in the coming years. It was recognized by the FOAC that FUSE will encounter difficulties in maintaining both a high level of data quality and preserving the current levels of scientific observing time. In light of this, the FOAC recognized that user services may suffer as a consequence.

Cycle 6 Status - Sonneborn:

  1. 183 proposals were received and 28.6 Msec proposed.
  2. Results are expected to be announced before the January AAS meeting.

Bright Target Observations:

An overview of the results of various "Overbright Target" tests was presented. The SiC only option, which provides 3-5X the nominal brightness limit, was deemed viable and is now being pushed to its useful limit. The Scattered Light Technique and the Defocus Technique have been demonstrated but have been shown to be difficult to implement. Substantial testing was done, involving nearly 1Ms of observing time and many FTE months of project time. The FOAC discussed these results and the project recommendations and has adopted the following statement.

FOAC Recommendation on Very Bright Target Observations:

The FOAC notes the significant effort that has been made by the FUSE project in developing workable schemes for observations of very bright targets. It is clear from the results of these tests that the routine implementation of such observations will not be possible. The level of effort needed to conduct and to reduce such observations is extensive and competes directly for limited project resources. The FOAC unanimously agreed that the Project Scientist has the authority to remove particular problem targets from the FUSE target list upon the recommendation of the FUSE project.

Therefore we recommend that:

  1. No further development of bright target techniques be undertaken.
  2. The Project Scientist should contact all PIs with pending bright target observations, asking that they carefully reevaluate the scientific case for making such observations. If after such consideration an overwhelmingly strong scientific case is presented by the PI for individual targets, NASA should consider whether an ad hoc peer review would be beneficial to help prioritize these observations.
  3. The Project Scientist is encouraged to offer PI's with impacted programs, appropriate observing time in compensation.
  4. The FUSE project should avoid bright target observations, or observations in proximity to bright targets, which might constitute unacceptable safety risks to the mission.

Action Items:

  1. The Project Scientist will seek a new FOAC member to replace Graham Harper.
  2. The Project is requested to inform FUSE observers when their data do not pass the automatic data quality checks and when there it has been decided not to reschedule those particular observations. A checklist of subsequent verifications will be provided so that observers can establish for themselves the validity of the data.
  3. The Project is requested to examine the possibility of flagging suspect data before it is sent to the MAST archives.
  4. The Project will consider and prioritize mission operations, data processing, data archiving and user support activities and report their conclusions and options at the next FOAC meeting.